Merge branch 'dev' into persisted-suspense

packages/app/e2e/performance/timeline-stability/README.md

@@ -0,0 +1,61 @@
+# Timeline Layout Continuity
+
+Run from `packages/app`:
+
+```sh
+bun run test:stability
+```
+
+The suite runs a production build in one Chromium worker. Selected scenarios use deterministic 4x CPU stress after application readiness. This is a stress profile, not emulation of a specific device.
+
+## What It Proves
+
+The continuity probe samples DOM-derived layout and visibility state across browser render opportunities. Tests declare explicit contracts such as:
+
+- Preserve a visible semantic anchor while the user is away from the bottom.
+- Preserve end anchoring while active content grows or new content appears.
+- Keep adjacent visible rows ordered without material overlap.
+- Keep user-selected disclosure state through updates and virtualization.
+- Avoid a sampled blank interval while one visible surface replaces another.
+- Preserve logical row and control identity where local state or focus depends on it.
+- Keep keyboard, wheel, and nested-scroll ownership consistent during remeasurement.
+
+The suite exercises real browser reducer, projection, component, virtualizer, layout, focus, and interaction code. The backend and event producer are controlled fixtures.
+
+## What It Does Not Prove
+
+The pass/fail oracle does not inspect every compositor-presented pixel. A sample taken after `requestAnimationFrame` is a DOM/layout observation, not proof that every sampled state was displayed or that every displayed frame was sampled.
+
+The suite does not provide complete coverage for:
+
+- Compositor-only or raster-only glitches.
+- Color, contrast, canvas, WebGL, masks, irregular clips, or arbitrary occlusion.
+- Physical display refresh rates, native OS scaling, or a named low-end device.
+- TCP packetization, proxy buffering, or the complete real server/provider pipeline.
+
+Playwright video, trace, screenshots, and observation JSON are diagnostic evidence. They are not pixel baselines and do not participate in normal pass/fail decisions.
+
+For optional before/violation/after screenshots, set `OPENCODE_STABILITY_CAPTURE=1`. Capture is opt-in because compositor readback can perturb timing.
+
+## Test Layers
+
+- **Projection:** admitted rows, grouping, labels, and final visible states.
+- **Local state:** disclosure state, identity, duplicate delivery, and virtualization restoration.
+- **Interaction:** wheel, keyboard, nested scrolling, actionability, and focus behavior.
+- **Layout continuity:** anchoring, adjacency, responsive reflow, and visible surface handoffs.
+- **Reducer hardening:** validly shaped but intentionally reordered, duplicated, removed, or replaced events.
+- **Oracle contract:** pure analyzer and browser sampler calibration tests.
+
+Production-lifecycle fixtures should model states emitted by the current producer. Impossible or reordered sequences belong in reducer-hardening tests and must not be described as normal provider behavior.
+
+## Diagnostics
+
+Failures retain:
+
+- `video.webm`
+- `trace.zip`
+- failure screenshot
+- sampled DOM/layout trace JSON
+- event markers and summarized violations
+
+The analyzer records both unclipped layout bounds and ancestor-clipped visible intersections. Scrollbar and raw `scrollTop` changes alone do not fail continuity checks; user-visible semantic anchor movement does.

packages/app/e2e/performance/timeline-stability/adverse.spec.ts

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+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  shell,
+  textPart,
+  toolPart,
+  userMessage,
+  waitForVisualSettle,
+  type TimelineMessage,
+} from "./fixture"
+
+test.describe("timeline adverse visual stability", () => {
+  test("does not pull a scrolled-away user while an active shell grows", async ({ page }, testInfo) => {
+    const activeShellID = "prt_adverse_01_shell"
+    const messages = [
+      ...history(24),
+      userMessage(),
+      assistantMessage([shell(activeShellID, "running")], { completed: false }),
+    ]
+    const timeline = await setupTimeline(page, {
+      messages,
+      settings: { shellToolPartsExpanded: true },
+      cpuRate: 4,
+      eventRetry: 30,
+    })
+    const scroller = page.locator(".scroll-view__viewport", {
+      has: page.locator('[data-timeline-row="AssistantPart"]'),
+    })
+    await scroller.evaluate((element) => {
+      element.dispatchEvent(new WheelEvent("wheel", { bubbles: true, cancelable: true, deltaY: -450 }))
+      element.scrollTop = Math.max(0, element.scrollHeight - element.clientHeight - 450)
+    })
+    await page.waitForTimeout(150)
+    await expect
+      .poll(() => scroller.evaluate((element) => element.scrollHeight - element.clientHeight - element.scrollTop))
+      .toBeGreaterThan(100)
+    const anchor = await scroller.evaluate((element) => {
+      const view = element.getBoundingClientRect()
+      return [...element.querySelectorAll<HTMLElement>("[data-timeline-key]")].find((row) => {
+        const rect = row.getBoundingClientRect()
+        return rect.top >= view.top + 40 && rect.bottom <= view.bottom - 40
+      })?.dataset.timelineKey
+    })
+    expect(anchor).toBeTruthy()
+    await waitForVisualSettle(page, [`[data-timeline-key="${anchor}"]`])
+
+    const regions = defineVisualRegions({
+      anchor: { selector: `[data-timeline-key="${anchor}"]` },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(shell(activeShellID, "running", lines(1))), 180)
+    await timeline.send(partUpdated(shell(activeShellID, "running", lines(10))), 90)
+    await timeline.send(partUpdated(shell(activeShellID, "running", lines(50))), 350)
+    await timeline.send(partUpdated(shell(activeShellID, "completed", lines(50))), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "scrolled-away-shell",
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: ["anchor"] },
+        { type: "unique", regions: ["anchor"] },
+        { type: "stable", regions: ["anchor"] },
+        { type: "fixed", regions: ["anchor"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+      ]),
+    )
+  })
+
+  test("preserves an explicit shell state across virtualization", async ({ page }) => {
+    const targetID = "prt_virtual_shell"
+    const messages = [
+      userMessage(undefined, { id: "msg_0000_virtual_user", created: 1700000000000 }),
+      assistantMessage([shell(targetID, "completed", lines(20))], {
+        id: "msg_0001_virtual_assistant",
+        parentID: "msg_0000_virtual_user",
+        created: 1700000001000,
+      }),
+      ...history(35, 10),
+    ]
+    await setupTimeline(page, { messages, settings: { shellToolPartsExpanded: false } })
+    const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+    await scroller.evaluate((element) => {
+      element.dispatchEvent(new WheelEvent("wheel", { bubbles: true, cancelable: true, deltaY: -1_000 }))
+      element.scrollTop = 0
+    })
+    await page.waitForTimeout(300)
+    const trigger = page.locator(`[data-timeline-part-id="${targetID}"] [data-slot="collapsible-trigger"]`)
+    await expect(trigger).toBeVisible()
+    await trigger.click()
+    await expect(trigger).toHaveAttribute("aria-expanded", "true")
+
+    await scroller.evaluate((element) => (element.scrollTop = element.scrollHeight))
+    await expect(page.locator(`[data-timeline-part-id="${targetID}"]`)).toHaveCount(0)
+    await scroller.evaluate((element) => (element.scrollTop = 0))
+    await expect(trigger).toBeVisible()
+    await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  })
+
+  test("keeps narrow viewport rows ordered during long shell growth", async ({ page }, testInfo) => {
+    const shellID = "prt_narrow_01_shell"
+    const followingID = "prt_narrow_02_following"
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage(
+          [shell(shellID, "running"), textPart(followingID, "A narrow following row that wraps across lines.")],
+          {
+            completed: false,
+          },
+        ),
+      ],
+      settings: { shellToolPartsExpanded: true },
+      viewport: { width: 430, height: 800 },
+      cpuRate: 4,
+    })
+    await waitForVisualSettle(page, [
+      `[data-timeline-part-id="${shellID}"]`,
+      `[data-timeline-part-id="${followingID}"]`,
+    ])
+    const regions = defineVisualRegions({
+      shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(shell(shellID, "running", wideLines(10))), 100)
+    await timeline.send(partUpdated(shell(shellID, "running", wideLines(50))), 300)
+    await timeline.send(partUpdated(shell(shellID, "completed", wideLines(50))), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "narrow-shell",
+      trace,
+      visualPlan(
+        regions,
+        [
+          { type: "required", regions: ["shell", "following"] },
+          { type: "unique", regions: ["shell", "following"] },
+          { type: "stable", regions: ["shell", "following"] },
+          { type: "opacity", regions: "all" },
+          { type: "continuity", regions: "all" },
+          { type: "motion", regions: "all", maxPositionReversals: 0 },
+          { type: "label-stability", regions: "all" },
+          { type: "preserve-bottom-anchor" },
+          { type: "flow", regions: ["shell", "following"] },
+        ],
+        { perMarker: true },
+      ),
+    )
+  })
+
+  test("keeps visible rows ordered while resizing desktop to narrow and back", async ({ page }, testInfo) => {
+    const shellID = "prt_resize_01_shell"
+    const contextIDs = ["prt_resize_02_read", "prt_resize_03_glob"]
+    const followingID = "prt_resize_04_following"
+    await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([
+          shell(shellID, "completed", wideLines(15)),
+          toolPart(contextIDs[0]!, "read", "completed", { filePath: "src/a.ts" }),
+          toolPart(contextIDs[1]!, "glob", "completed", { path: ".", pattern: "**/*.ts" }),
+          textPart(followingID, "Following responsive timeline content that wraps on narrow screens."),
+        ]),
+      ],
+      settings: { shellToolPartsExpanded: true },
+      cpuRate: 4,
+      seedHistory: true,
+    })
+    const group = `[data-timeline-part-ids="${contextIDs.join(",")}"]`
+    const regions = defineVisualRegions({
+      shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      context: { selector: group, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await page.setViewportSize({ width: 430, height: 800 })
+    await page.waitForTimeout(500)
+    await page.setViewportSize({ width: 900, height: 800 })
+    await page.waitForTimeout(500)
+    await page.setViewportSize({ width: 1400, height: 900 })
+    await page.waitForTimeout(500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "responsive-resize",
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: ["shell", "context", "following"] },
+        { type: "unique", regions: ["shell", "context", "following"] },
+        { type: "stable", regions: ["shell", "context", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 4, maxReversals: 4 },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["shell", "context", "following"] },
+      ]),
+    )
+  })
+})
+
+function history(count: number, offset = 0): TimelineMessage[] {
+  return Array.from({ length: count }, (_, index) => {
+    const value = index + offset
+    const prefix = `msg_0${String(value).padStart(3, "0")}_history`
+    const userID = `${prefix}_a_user`
+    return [
+      userMessage(undefined, { id: userID, created: 1699990000000 + value * 10_000 }),
+      assistantMessage(
+        [
+          textPart(
+            `prt_history_${String(value).padStart(3, "0")}`,
+            `Historical response ${value}. ${"Stable history content. ".repeat(8)}`,
+          ),
+        ],
+        {
+          id: `${prefix}_b_assistant`,
+          parentID: userID,
+          created: 1699990001000 + value * 10_000,
+        },
+      ),
+    ]
+  }).flat()
+}
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}
+
+function wideLines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1} ${"wide-output-".repeat(20)}`).join("\n")
+}

packages/app/e2e/performance/timeline-stability/context-matrix.spec.ts

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+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantID,
+  assistantMessage,
+  event,
+  partUpdated,
+  setupTimeline,
+  textPart,
+  toolPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+const inputs = {
+  read: { filePath: "src/a.ts", offset: 0, limit: 120 },
+  glob: { path: ".", pattern: "**/*.ts" },
+  grep: { path: ".", pattern: "stable", include: "*.ts" },
+  list: { path: "src" },
+}
+
+test("appends context operations while the group is expanded", async ({ page }, testInfo) => {
+  const firstID = "prt_append_01_read"
+  const followingID = "prt_append_99_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([toolPart(firstID, "read", "running", inputs.read), textPart(followingID, "Following append")], {
+        completed: false,
+      }),
+    ],
+    cpuRate: 4,
+  })
+  const initialGroup = `[data-timeline-part-ids="${firstID}"]`
+  await page.locator(`${initialGroup} [data-slot="collapsible-trigger"]`).click()
+  await waitForVisualSettle(page, [initialGroup, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    context: {
+      selector: '[data-timeline-part-ids^="prt_append_01_read"]',
+      closest: '[data-timeline-row="AssistantPart"]',
+    },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(toolPart("prt_append_02_glob", "glob", "running", inputs.glob)), 180)
+  await timeline.send(partUpdated(toolPart("prt_append_03_grep", "grep", "completed", inputs.grep)), 240)
+  await timeline.send(partUpdated(toolPart("prt_append_04_list", "list", "completed", inputs.list)), 500)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "context-append",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["context", "following"] },
+        { type: "unique", regions: ["context", "following"] },
+        { type: "stable", regions: ["context", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: ["following"], maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["context", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+  await expect(
+    page.locator(
+      '[data-timeline-part-ids="prt_append_01_read,prt_append_02_glob,prt_append_03_grep,prt_append_04_list"]',
+    ),
+  ).toBeVisible()
+  await expect(
+    page.locator('[data-timeline-part-ids^="prt_append_01_read"] [data-slot="collapsible-trigger"]'),
+  ).toHaveAttribute("aria-expanded", "true")
+})
+
+test("splits and merges context groups when a middle text part changes", async ({ page }, testInfo) => {
+  const textID = "prt_split_02_text"
+  const followingID = "prt_split_99_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart("prt_split_01_read", "read", "completed", inputs.read),
+        textPart(textID, "Boundary"),
+        toolPart("prt_split_03_glob", "glob", "completed", inputs.glob),
+        textPart(followingID, "Following split groups"),
+      ]),
+    ],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    event("message.part.removed", { sessionID: "ses_timeline_stability", messageID: assistantID, partID: textID }),
+    500,
+  )
+  await expect(page.locator('[data-timeline-part-ids="prt_split_01_read,prt_split_03_glob"]')).toBeVisible()
+  await timeline.send(partUpdated(textPart(textID, "Boundary restored")), 500)
+  await expect(page.locator('[data-timeline-part-ids="prt_split_01_read"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-part-ids="prt_split_03_glob"]')).toBeVisible()
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "context-split-merge",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["following"] },
+        { type: "unique", regions: ["following"] },
+        { type: "stable", regions: ["following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 1 },
+        { type: "label-stability", regions: "all" },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+test("removing the first context member replaces the group once without overlapping following content", async ({
+  page,
+}, testInfo) => {
+  const ids = ["prt_key_01_read", "prt_key_02_glob", "prt_key_03_grep"]
+  const followingID = "prt_key_99_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(ids[0]!, "read", "completed", inputs.read),
+        toolPart(ids[1]!, "glob", "completed", inputs.glob),
+        toolPart(ids[2]!, "grep", "completed", inputs.grep),
+        textPart(followingID, "Following replaced group"),
+      ]),
+    ],
+    cpuRate: 4,
+  })
+  const original = page.locator(`[data-timeline-part-ids="${ids.join(",")}"]`)
+  const originalRowKey = await original.evaluate((element) =>
+    element.closest("[data-timeline-key]")?.getAttribute("data-timeline-key"),
+  )
+  await original.locator('[data-slot="collapsible-trigger"]').click()
+  await expect(original.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "true")
+  const regions = defineVisualRegions({
+    context: {
+      selector: '[data-timeline-part-ids*="prt_key_02_glob"]',
+      closest: '[data-timeline-row="AssistantPart"]',
+    },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    event("message.part.removed", { sessionID: "ses_timeline_stability", messageID: assistantID, partID: ids[0] }),
+    500,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "context-first-remove",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["context", "following"] },
+      { type: "unique", regions: ["context", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0 },
+      { type: "label-stability", regions: "all" },
+      { type: "flow", regions: ["context", "following"] },
+    ]),
+  )
+  await expect(page.locator(`[data-timeline-part-ids="${ids.slice(1).join(",")}"]`)).toBeVisible()
+  expect(
+    await page
+      .locator(`[data-timeline-part-ids="${ids.slice(1).join(",")}"]`)
+      .evaluate((element) => element.closest("[data-timeline-key]")?.getAttribute("data-timeline-key")),
+  ).toBe(originalRowKey)
+  await expect(
+    page.locator(`[data-timeline-part-ids="${ids.slice(1).join(",")}"] [data-slot="collapsible-trigger"]`),
+  ).toHaveAttribute("aria-expanded", "true")
+})

packages/app/e2e/performance/timeline-stability/environment-matrix.spec.ts

@@ -0,0 +1,113 @@
+import { test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  shell,
+  textPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+// Fractional scaling exercises different browser rounding than the baseline.
+for (const deviceScaleFactor of [1, 1.25]) {
+  test(`keeps shell growth ordered at device scale ${deviceScaleFactor}`, async ({ page }, testInfo) => {
+    const shellID = `prt_dpr_${String(deviceScaleFactor).replace(".", "_")}_01_shell`
+    const followingID = `prt_dpr_${String(deviceScaleFactor).replace(".", "_")}_02_following`
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([shell(shellID, "running"), textPart(followingID, "Following scaled shell")], {
+          completed: false,
+        }),
+      ],
+      settings: { shellToolPartsExpanded: true },
+      cpuRate: 4,
+      deviceScaleFactor,
+      seedHistory: true,
+    })
+    await waitForVisualSettle(page, [
+      `[data-timeline-part-id="${shellID}"]`,
+      `[data-timeline-part-id="${followingID}"]`,
+    ])
+    const regions = defineVisualRegions({
+      shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(shell(shellID, "running", lines(20))), 180)
+    await timeline.send(partUpdated(shell(shellID, "completed", lines(20))), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(testInfo, `dpr-${deviceScaleFactor}`, trace, shellPlan(regions))
+  })
+}
+
+for (const reducedMotion of [true]) {
+  test(`keeps shell and status transitions ordered with reduced motion ${reducedMotion}`, async ({
+    page,
+  }, testInfo) => {
+    const shellID = `prt_motion_${reducedMotion}_01_shell`
+    const followingID = `prt_motion_${reducedMotion}_02_following`
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([shell(shellID, "running"), textPart(followingID, "Following motion profile")], {
+          completed: false,
+        }),
+      ],
+      settings: { shellToolPartsExpanded: true },
+      reducedMotion,
+      cpuRate: 4,
+      seedHistory: true,
+    })
+    await waitForVisualSettle(page, [
+      `[data-timeline-part-id="${shellID}"]`,
+      `[data-timeline-part-id="${followingID}"]`,
+    ])
+    const regions = defineVisualRegions({
+      shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(shell(shellID, "completed", lines(10))), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(testInfo, `reduced-motion-${reducedMotion}`, trace, shellPlan(regions))
+  })
+}
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}
+
+function shellPlan<Regions extends ReturnType<typeof defineVisualRegions>>(
+  regions: Regions & Record<"shell" | "following", { selector: string }>,
+) {
+  return visualPlan(
+    regions,
+    [
+      { type: "required", regions: ["shell", "following"] },
+      { type: "unique", regions: ["shell", "following"] },
+      { type: "stable", regions: ["shell", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0 },
+      { type: "label-stability", regions: "all" },
+      { type: "preserve-bottom-anchor" },
+      { type: "flow", regions: ["shell", "following"] },
+    ],
+    { perMarker: true },
+  )
+}

packages/app/e2e/performance/timeline-stability/file-matrix.spec.ts

@@ -0,0 +1,121 @@
+import { test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  textPart,
+  toolPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+const profiles = [
+  { name: "edit", tool: "edit", input: { filePath: "src/edit.ts" } },
+  {
+    name: "multi patch",
+    tool: "apply_patch",
+    input: { files: ["src/a.ts", "src/b.ts", "src/old.ts", "src/moved.ts"] },
+  },
+] as const
+
+for (const profile of profiles) {
+  test(`stabilizes ${profile.name} pending to completed`, async ({ page }, testInfo) => {
+    const partID = `prt_file_matrix_${profiles.indexOf(profile)}`
+    const followingID = `prt_file_matrix_following_${profiles.indexOf(profile)}`
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage(
+          [
+            toolPart(partID, profile.tool, "pending", profile.input),
+            textPart(followingID, `Following ${profile.name}`),
+          ],
+          { completed: false },
+        ),
+      ],
+      settings: { editToolPartsExpanded: true },
+      cpuRate: 4,
+    })
+    await waitForVisualSettle(page, [`[data-timeline-part-id="${partID}"]`, `[data-timeline-part-id="${followingID}"]`])
+    const regions = defineVisualRegions({
+      tool: { selector: `[data-timeline-part-id="${partID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(toolPart(partID, profile.tool, "running", profile.input)), 180)
+    await timeline.send(partUpdated(completedPart(partID, profile)), 900)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      `file-${profile.name}`,
+      trace,
+      visualPlan(
+        regions,
+        [
+          { type: "required", regions: ["tool", "following"] },
+          { type: "unique", regions: ["tool", "following"] },
+          { type: "stable", regions: ["tool", "following"] },
+          { type: "opacity", regions: "all" },
+          { type: "continuity", regions: "all" },
+          { type: "motion", regions: "all", maxPositionReversals: 0, maxReversals: 1 },
+          { type: "label-stability", regions: "all" },
+          { type: "preserve-bottom-anchor" },
+          { type: "flow", regions: ["tool", "following"] },
+        ],
+        { perMarker: true },
+      ),
+    )
+  })
+}
+
+function completedPart(partID: string, profile: (typeof profiles)[number]) {
+  if (profile.tool === "edit") {
+    return toolPart(partID, profile.tool, "completed", profile.input, {
+      metadata: {
+        filediff: {
+          file: "src/edit.ts",
+          additions: 50,
+          deletions: 50,
+          before: source(50, false),
+          after: source(50, true),
+        },
+      },
+    })
+  }
+  const files = [
+    patchFile("src/a.ts", "update"),
+    patchFile("src/b.ts", "add"),
+    patchFile("src/old.ts", "delete"),
+    { ...patchFile("src/moved.ts", "move"), move: "src/new-place.ts" },
+  ]
+  return toolPart(partID, profile.tool, "completed", profile.input, { metadata: { files } })
+}
+
+function patchFile(filePath: string, type: "add" | "update" | "delete" | "move") {
+  return {
+    filePath,
+    relativePath: filePath,
+    type,
+    additions: type === "delete" ? 0 : 20,
+    deletions: type === "add" ? 0 : 20,
+    before: type === "add" ? undefined : source(20, false),
+    after: type === "delete" ? undefined : source(20, true),
+  }
+}
+
+function source(count: number, changed: boolean) {
+  return Array.from(
+    { length: count },
+    (_, index) => `export const value${index} = ${changed ? index + 1 : index}\n`,
+  ).join("")
+}

packages/app/e2e/performance/timeline-stability/file-mutation.spec.ts

@@ -0,0 +1,113 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  textPart,
+  toolPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+test("adds patch files incrementally without resetting outer expansion", async ({ page }, testInfo) => {
+  const patchID = "prt_incremental_01_patch"
+  const followingID = "prt_incremental_02_following"
+  const first = patchFile("src/a.ts", "update")
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage(
+        [
+          toolPart(patchID, "apply_patch", "running", { files: [first.filePath] }, { metadata: { files: [first] } }),
+          textPart(followingID, "Following incremental patch"),
+        ],
+        { completed: false },
+      ),
+    ],
+    settings: { editToolPartsExpanded: true },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  const trigger = page.locator(`[data-timeline-part-id="${patchID}"] [data-slot="collapsible-trigger"]`).first()
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${patchID}"]`, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    patch: { selector: `[data-timeline-part-id="${patchID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  const second = patchFile("src/b.ts", "add")
+  const third = patchFile("src/old.ts", "delete")
+  await timeline.send(
+    partUpdated(
+      toolPart(
+        patchID,
+        "apply_patch",
+        "running",
+        { files: [first.filePath, second.filePath] },
+        { metadata: { files: [first, second] } },
+      ),
+    ),
+    240,
+  )
+  await timeline.send(
+    partUpdated(
+      toolPart(
+        patchID,
+        "apply_patch",
+        "completed",
+        { files: [first.filePath, second.filePath, third.filePath] },
+        { metadata: { files: [first, second, third] } },
+      ),
+    ),
+    800,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "incremental-patch",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["patch", "following"] },
+        { type: "unique", regions: ["patch", "following"] },
+        { type: "stable", regions: ["patch", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: ["following"], maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["patch", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await expect(page.locator('[data-scope="apply-patch"] [data-type="delete"]')).toBeVisible()
+})
+
+function patchFile(filePath: string, type: "add" | "update" | "delete") {
+  return {
+    filePath,
+    relativePath: filePath,
+    type,
+    additions: type === "delete" ? 0 : 4,
+    deletions: type === "add" ? 0 : 3,
+    before: type === "add" ? undefined : source(false),
+    after: type === "delete" ? undefined : source(true),
+  }
+}
+
+function source(changed: boolean) {
+  return Array.from({ length: 12 }, (_, index) => `export const value${index} = ${changed ? index + 1 : index}\n`).join(
+    "",
+  )
+}

packages/app/e2e/performance/timeline-stability/fixture.test.ts

@@ -0,0 +1,68 @@
+import { describe, expect, test } from "bun:test"
+import {
+  assistantMessage,
+  event,
+  toolPart,
+  userMessage,
+  validateTimelineEvent,
+  validateTimelineMessages,
+  type PartSeed,
+} from "./fixture"
+
+describe("timeline fixture validation", () => {
+  test("accepts a valid timeline", () => {
+    expect(validateTimelineMessages([userMessage(), assistantMessage()])).toHaveLength(2)
+  })
+
+  test("rejects malformed SDK values at runtime", () => {
+    expect(() =>
+      assistantMessage([], {
+        error: { name: "APIError", data: { message: "failed" } } as never,
+      }),
+    ).toThrow()
+    expect(() =>
+      validateTimelineEvent({
+        directory: "C:/OpenCode/TimelineStability",
+        payload: {
+          id: "evt_invalid_status",
+          type: "session.status",
+          properties: { sessionID: "ses_timeline_stability", status: { type: "retry", attempt: 1 } },
+        },
+      }),
+    ).toThrow()
+  })
+
+  test("rejects duplicate IDs and orphan assistants", () => {
+    expect(() => validateTimelineMessages([userMessage(), userMessage()])).toThrow(/duplicate message ID/)
+    expect(() =>
+      validateTimelineMessages([userMessage(), assistantMessage([], { parentID: "msg_missing_parent" })]),
+    ).toThrow(/parent user/)
+  })
+
+  test("assigns deterministic event IDs", () => {
+    const first = event("session.status", { sessionID: "ses_timeline_stability", status: { type: "busy" } })
+    const second = event("session.status", { sessionID: "ses_timeline_stability", status: { type: "idle" } })
+    expect(first.payload.id).toMatch(/^evt_timeline_\d{4}$/)
+    expect(Number(second.payload.id.slice(-4))).toBe(Number(first.payload.id.slice(-4)) + 1)
+  })
+})
+
+if (false) {
+  const userSeed = { id: "prt_type_user", type: "text", text: "typed" } satisfies PartSeed<"user">
+  userMessage([userSeed])
+
+  // @ts-expect-error Tool completion fields are not valid while pending.
+  toolPart("prt_invalid_pending", "bash", "pending", {}, { output: "impossible" })
+  // @ts-expect-error Tool completion fields are not valid while running.
+  toolPart("prt_invalid_running", "bash", "running", {}, { output: "impossible" })
+  // @ts-expect-error Tool error fields are not valid after completion.
+  toolPart("prt_invalid_completed", "bash", "completed", {}, { error: "impossible" })
+
+  assistantMessage([
+    // @ts-expect-error Agent references belong to user messages, not assistant messages.
+    { id: "prt_invalid_owner", type: "agent", name: "explore", source: { value: "@explore", start: 0, end: 8 } },
+  ])
+
+  // @ts-expect-error Retry status events require message and next.
+  event("session.status", { sessionID: "ses_timeline_stability", status: { type: "retry", attempt: 1 } })
+}

packages/app/e2e/performance/timeline-stability/fixture.ts

@@ -0,0 +1,561 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { Event } from "@opencode-ai/schema/event"
+import { SessionStatusEvent } from "@opencode-ai/schema/session-status-event"
+import { SessionV1 } from "@opencode-ai/schema/session-v1"
+import type {
+  AssistantMessage,
+  GlobalEvent,
+  Message,
+  Part,
+  Session,
+  SessionStatus,
+  ToolPart,
+  ToolState,
+  UserMessage,
+} from "@opencode-ai/sdk/v2/client"
+import { expect, type Page } from "@playwright/test"
+import { Schema } from "effect"
+import { mockOpenCodeServer } from "../../utils/mock-server"
+import { installSseTransport } from "../../utils/sse-transport"
+import { expectSessionTitle } from "../../utils/waits"
+
+export const directory = "C:/OpenCode/TimelineStability"
+export const projectID = "proj_timeline_stability"
+export const sessionID = "ses_timeline_stability"
+export const userID = "msg_1000_timeline_user"
+export const assistantID = "msg_1001_timeline_assistant"
+export const title = "Timeline visual stability"
+export const model = { providerID: "opencode", modelID: "claude-opus-4-6", variant: "max" }
+
+type TimelinePayload = Extract<
+  GlobalEvent["payload"],
+  {
+    type:
+      | "message.updated"
+      | "message.removed"
+      | "message.part.updated"
+      | "message.part.removed"
+      | "message.part.delta"
+      | "session.status"
+  }
+>
+
+type DeepReadonly<Value> = Value extends readonly unknown[]
+  ? { readonly [Key in keyof Value]: DeepReadonly<Value[Key]> }
+  : Value extends object
+    ? { readonly [Key in keyof Value]: DeepReadonly<Value[Key]> }
+    : Value
+
+export type TimelineEvent = DeepReadonly<Omit<GlobalEvent, "payload"> & { payload: TimelinePayload }>
+export type EventPayload = TimelineEvent
+export type ToolStatus = ToolState["status"]
+export type TimelineMessage = { info: UserMessage; parts: Part[] } | { info: AssistantMessage; parts: Part[] }
+
+type UserPart = Extract<Part, { type: "text" | "file" | "agent" | "subtask" }>
+type AssistantPart = Exclude<Part, { type: "agent" | "subtask" }>
+type OwnedPart<Owner extends Message["role"]> = Owner extends "user" ? UserPart : AssistantPart
+export type PartSeed<Owner extends Message["role"]> =
+  OwnedPart<Owner> extends infer Candidate
+    ? Candidate extends Part
+      ? Omit<Candidate, "sessionID" | "messageID">
+      : never
+    : never
+
+type ToolOptions<State extends ToolStatus> = State extends "pending"
+  ? { output?: never; title?: never; metadata?: never; error?: never }
+  : State extends "running"
+    ? { title?: string; metadata?: Record<string, unknown>; output?: never; error?: never }
+    : State extends "error"
+      ? { error?: string; metadata?: Record<string, unknown>; output?: never; title?: never }
+      : { output?: string; title?: string; metadata?: Record<string, unknown>; error?: never }
+
+const decodeOptions = { errors: "all", onExcessProperty: "error" } as const
+const decodeMessage = Schema.decodeUnknownSync(SessionV1.WithParts)
+const decodePart = Schema.decodeUnknownSync(SessionV1.Part)
+const decodeStatus = Schema.decodeUnknownSync(SessionStatusEvent.Info)
+const timelineEventSchema = Schema.Union([
+  eventSchema("message.updated", SessionV1.Event.MessageUpdated.data),
+  eventSchema("message.removed", SessionV1.Event.MessageRemoved.data),
+  eventSchema("message.part.updated", SessionV1.Event.PartUpdated.data),
+  eventSchema("message.part.removed", SessionV1.Event.PartRemoved.data),
+  eventSchema("message.part.delta", SessionV1.Event.PartDelta.data),
+  eventSchema("session.status", SessionStatusEvent.Status.data),
+])
+const decodeEvent = Schema.decodeUnknownSync(timelineEventSchema)
+let eventSequence = 0
+
+export async function setupTimeline(
+  page: Page,
+  input: {
+    messages?: TimelineMessage[]
+    settings?: Record<string, boolean>
+    sessions?: Session[]
+    cpuRate?: number
+    viewport?: { width: number; height: number }
+    eventRetry?: number
+    reducedMotion?: boolean
+    locale?: string
+    deviceScaleFactor?: number
+    seedHistory?: boolean
+  } = {},
+) {
+  const sessions = input.sessions ?? [session()]
+  const messages = validateTimelineMessages([
+    ...(input.seedHistory ? historyMessages(18) : []),
+    ...(input.messages ?? [userMessage(), assistantMessage()]),
+  ])
+  const active = messages.findLast((message) => message.info.role === "assistant")
+  const initialStatus = decodeStatus(
+    active?.info.role === "assistant" && active.info.time.completed === undefined ? { type: "busy" } : { type: "idle" },
+    decodeOptions,
+  )
+  const transport = await installSseTransport<EventPayload>(page, {
+    server: `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`,
+    retry: input.eventRetry ?? 20,
+  })
+  await mockOpenCodeServer(page, {
+    directory,
+    project: project(),
+    provider: provider(),
+    sessions,
+    sessionStatus: { [sessionID]: initialStatus },
+    pageMessages: () => ({
+      items: messages,
+    }),
+  })
+  await page.addInitScript((settings) => {
+    localStorage.setItem(
+      "settings.v3",
+      JSON.stringify({
+        general: {
+          editToolPartsExpanded: false,
+          shellToolPartsExpanded: false,
+          showReasoningSummaries: false,
+          showSessionProgressBar: true,
+          ...settings,
+        },
+      }),
+    )
+  }, input.settings ?? {})
+  if (input.locale) {
+    await page.addInitScript((locale) => {
+      localStorage.setItem("opencode.global.dat:language", JSON.stringify({ locale }))
+    }, input.locale)
+  }
+  if (input.reducedMotion) await page.emulateMedia({ reducedMotion: "reduce" })
+  await page.setViewportSize(input.viewport ?? { width: 1400, height: 900 })
+  if (input.deviceScaleFactor) {
+    const devtools = await page.context().newCDPSession(page)
+    const viewport = input.viewport ?? { width: 1400, height: 900 }
+    await devtools.send("Emulation.setDeviceMetricsOverride", {
+      width: viewport.width,
+      height: viewport.height,
+      deviceScaleFactor: input.deviceScaleFactor,
+      mobile: false,
+    })
+  }
+  await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+  await transport.waitForConnection()
+  await expectSessionTitle(page, title)
+  if (input.cpuRate && input.cpuRate > 1) {
+    const devtools = await page.context().newCDPSession(page)
+    await devtools.send("Emulation.setCPUThrottlingRate", { rate: input.cpuRate })
+  }
+
+  return {
+    transport,
+    async send(event: TimelineEvent, delay = 0) {
+      const valid = validateTimelineEvent(event)
+      await transport.send(valid, { marker: describeEvent(valid) })
+      if (delay) await page.waitForTimeout(delay)
+    },
+    async sendAll(sequence: { event: TimelineEvent; delay: number }[]) {
+      for (const item of sequence) {
+        const valid = validateTimelineEvent(item.event)
+        await transport.send(valid, { marker: describeEvent(valid) })
+        await page.waitForTimeout(item.delay)
+      }
+    },
+    async settle(frames = 3) {
+      await page.evaluate(
+        (frames) =>
+          new Promise<void>((resolve) => {
+            let remaining = frames
+            const tick = () => {
+              remaining--
+              if (remaining <= 0) return resolve()
+              requestAnimationFrame(tick)
+            }
+            requestAnimationFrame(tick)
+          }),
+        frames,
+      )
+    },
+    async waitForPart(partID: string) {
+      await expect(page.locator(`[data-timeline-part-id="${partID}"]`).first()).toBeVisible()
+    },
+  }
+}
+
+function describeEvent(event: EventPayload) {
+  if (event.payload.type === "message.part.updated") {
+    const part = event.payload.properties.part
+    return [
+      event.payload.type,
+      part.id,
+      part.type === "tool" ? part.tool : part.type,
+      part.type === "tool" ? part.state.status : undefined,
+    ]
+      .filter(Boolean)
+      .join(":")
+  }
+  if (event.payload.type === "session.status") {
+    const status = event.payload.properties.status
+    return [event.payload.type, status.type, status.type === "retry" ? status.attempt : undefined]
+      .filter((value) => value !== undefined)
+      .join(":")
+  }
+  return event.payload.type
+}
+
+export function event<const Type extends TimelinePayload["type"]>(
+  type: Type,
+  properties: Extract<TimelinePayload, { type: Type }>["properties"],
+): TimelineEvent
+export function event(type: TimelinePayload["type"], properties: TimelinePayload["properties"]): TimelineEvent {
+  return validateTimelineEvent({
+    directory,
+    payload: { id: `evt_timeline_${String(++eventSequence).padStart(4, "0")}`, type, properties },
+  })
+}
+
+export function validateTimelineEvent(input: unknown): TimelineEvent {
+  return decodeEvent(input, decodeOptions)
+}
+
+export function validateTimelineMessages(input: readonly TimelineMessage[]): TimelineMessage[] {
+  input.forEach((message) => decodeMessage(message, decodeOptions))
+  const messages = [...input]
+  const messageIDs = new Set<string>()
+  const partIDs = new Set<string>()
+  const users = new Set(messages.filter((message) => message.info.role === "user").map((message) => message.info.id))
+
+  messages.forEach((message) => {
+    if (messageIDs.has(message.info.id))
+      throw new Error(`Timeline fixture has duplicate message ID: ${message.info.id}`)
+    messageIDs.add(message.info.id)
+    if (message.info.role === "assistant" && !users.has(message.info.parentID))
+      throw new Error(`Timeline assistant ${message.info.id} must reference a parent user in the fixture`)
+    message.parts.forEach((part) => {
+      if (part.sessionID !== message.info.sessionID || part.messageID !== message.info.id)
+        throw new Error(`Timeline part ${part.id} ownership does not match message ${message.info.id}`)
+      if (message.info.role === "user" && !["text", "file", "agent", "subtask"].includes(part.type))
+        throw new Error(`Timeline user message ${message.info.id} cannot own ${part.type} part ${part.id}`)
+      if (message.info.role === "assistant" && ["agent", "subtask"].includes(part.type))
+        throw new Error(`Timeline assistant message ${message.info.id} cannot own ${part.type} part ${part.id}`)
+      if (partIDs.has(part.id)) throw new Error(`Timeline fixture has duplicate part ID: ${part.id}`)
+      partIDs.add(part.id)
+    })
+  })
+  return messages
+}
+
+export async function waitForVisualSettle(page: Page, selectors: string[], stableFrames = 3) {
+  await page.waitForFunction(
+    ({ selectors, stableFrames }) => {
+      const elements = selectors.map((selector) => document.querySelector<HTMLElement>(selector))
+      if (elements.some((element) => !element)) return false
+      return new Promise<boolean>((resolve) => {
+        let stable = 0
+        let previous = ""
+        const sample = () => {
+          const signature = JSON.stringify(
+            elements.map((element) => {
+              const rect = element!.getBoundingClientRect()
+              return [Math.round(rect.top * 10), Math.round(rect.bottom * 10), Math.round(rect.height * 10)]
+            }),
+          )
+          stable = signature === previous ? stable + 1 : 0
+          previous = signature
+          const ordered = elements
+            .slice(1)
+            .every(
+              (element, index) =>
+                elements[index]!.getBoundingClientRect().bottom <= element!.getBoundingClientRect().top + 0.5,
+            )
+          if (stable >= stableFrames && ordered) return resolve(true)
+          requestAnimationFrame(sample)
+        }
+        requestAnimationFrame(sample)
+      })
+    },
+    { selectors, stableFrames },
+  )
+}
+
+export function historyMessages(count: number): TimelineMessage[] {
+  return Array.from({ length: count }, (_, index) => {
+    const value = String(index).padStart(4, "0")
+    const historyUserID = `msg_0${value}_history_a_user`
+    return [
+      userMessage(undefined, { id: historyUserID, created: 1690000000000 + index * 10_000 }),
+      assistantMessage(
+        [
+          {
+            id: `prt_0${value}_history_text`,
+            type: "text",
+            text: `Historical response ${index}. ${"Existing session content keeps the virtual timeline realistic. ".repeat(5)}`,
+          },
+        ],
+        {
+          id: `msg_0${value}_history_b_assistant`,
+          parentID: historyUserID,
+          created: 1690000001000 + index * 10_000,
+        },
+      ),
+    ]
+  }).flat()
+}
+
+export function partUpdated(part: Part | PartSeed<"assistant">) {
+  const owned = "messageID" in part ? part : { ...part, sessionID, messageID: assistantID }
+  decodePart(owned, decodeOptions)
+  return event("message.part.updated", {
+    sessionID,
+    part: owned,
+    time: 1700000002000,
+  })
+}
+
+export function partDelta(partID: string, delta: string, messageID = assistantID) {
+  return event("message.part.delta", { sessionID, messageID, partID, field: "text", delta })
+}
+
+export function messageUpdated(info: Message) {
+  return event("message.updated", { sessionID, info })
+}
+
+export function status(type: SessionStatus["type"], attempt = 1) {
+  return event("session.status", {
+    sessionID,
+    status: type === "retry" ? { type, attempt, message: "Rate limited", next: 1700000010000 } : { type },
+  })
+}
+
+export function userMessage(
+  parts?: PartSeed<"user">[],
+  input: { id?: string; summary?: UserMessage["summary"]; created?: number } = {},
+): Extract<TimelineMessage, { info: { role: "user" } }> {
+  const id = input.id ?? userID
+  const seeds = parts ?? [userText("Build the timeline stability matrix.", { id: `prt_${id}_text` })]
+  const message = {
+    info: {
+      id,
+      sessionID,
+      role: "user",
+      time: { created: input.created ?? 1700000000000 },
+      summary: input.summary ?? { diffs: [] },
+      agent: "build",
+      model,
+    },
+    parts: seeds.map((part) => ({
+      ...part,
+      sessionID,
+      messageID: id,
+    })),
+  } satisfies Extract<TimelineMessage, { info: { role: "user" } }>
+  decodeMessage(message, decodeOptions)
+  return message
+}
+
+export function assistantMessage(
+  parts: PartSeed<"assistant">[] = [],
+  input: {
+    id?: string
+    parentID?: string
+    completed?: boolean
+    error?: AssistantMessage["error"]
+    created?: number
+  } = {},
+): Extract<TimelineMessage, { info: { role: "assistant" } }> {
+  const id = input.id ?? assistantID
+  const message = {
+    info: {
+      id,
+      sessionID,
+      role: "assistant",
+      time: {
+        created: input.created ?? 1700000001000,
+        ...(input.completed === false ? {} : { completed: (input.created ?? 1700000001000) + 1_000 }),
+      },
+      parentID: input.parentID ?? userID,
+      modelID: model.modelID,
+      providerID: model.providerID,
+      mode: "build",
+      agent: "build",
+      path: { cwd: directory, root: directory },
+      cost: 0.01,
+      tokens: { input: 100, output: 200, reasoning: 0, cache: { read: 0, write: 0 } },
+      variant: "max",
+      ...(input.error ? { error: input.error } : {}),
+    },
+    parts: parts.map((part) => ({ ...part, sessionID, messageID: id })),
+  } satisfies Extract<TimelineMessage, { info: { role: "assistant" } }>
+  decodeMessage(message, decodeOptions)
+  return message
+}
+
+export function userText(
+  text: string,
+  input: Partial<Omit<Extract<PartSeed<"user">, { type: "text" }>, "type" | "text">> = {},
+): Extract<PartSeed<"user">, { type: "text" }> {
+  return { id: "prt_user_text", type: "text", text, ...input }
+}
+
+export function textPart(id: string, text: string): Extract<PartSeed<"assistant">, { type: "text" }> {
+  return { id, type: "text", text }
+}
+
+export function reasoningPart(id: string, text: string): Extract<PartSeed<"assistant">, { type: "reasoning" }> {
+  return { id, type: "reasoning", text, time: { start: 1700000001000 } }
+}
+
+export function toolPart(
+  id: string,
+  tool: string,
+  state: "pending",
+  input: Record<string, unknown>,
+  options?: ToolOptions<"pending">,
+): Omit<ToolPart, "sessionID" | "messageID">
+export function toolPart(
+  id: string,
+  tool: string,
+  state: "running",
+  input: Record<string, unknown>,
+  options?: ToolOptions<"running">,
+): Omit<ToolPart, "sessionID" | "messageID">
+export function toolPart(
+  id: string,
+  tool: string,
+  state: "completed",
+  input: Record<string, unknown>,
+  options?: ToolOptions<"completed">,
+): Omit<ToolPart, "sessionID" | "messageID">
+export function toolPart(
+  id: string,
+  tool: string,
+  state: "error",
+  input: Record<string, unknown>,
+  options?: ToolOptions<"error">,
+): Omit<ToolPart, "sessionID" | "messageID">
+export function toolPart(
+  id: string,
+  tool: string,
+  state: ToolStatus,
+  input: Record<string, unknown>,
+  options: ToolOptions<ToolStatus> = {},
+): Omit<ToolPart, "sessionID" | "messageID"> {
+  const base = { id, type: "tool" as const, callID: `call_${id}`, tool }
+  if (state === "pending") return { ...base, state: { status: state, input, raw: "" } }
+  if (state === "running")
+    return {
+      ...base,
+      state: {
+        status: state,
+        input,
+        title: options.title,
+        metadata: options.metadata ?? {},
+        time: { start: 1700000001000 },
+      },
+    }
+  if (state === "error")
+    return {
+      ...base,
+      state: {
+        status: state,
+        input,
+        error: options.error ?? "Tool failed",
+        metadata: options.metadata ?? {},
+        time: { start: 1700000001000, end: 1700000002000 },
+      },
+    }
+  return {
+    ...base,
+    state: {
+      status: state,
+      input,
+      output: options.output ?? "Completed",
+      title: options.title ?? tool,
+      metadata: options.metadata ?? {},
+      time: { start: 1700000001000, end: 1700000002000 },
+    },
+  }
+}
+
+export function shell(
+  id: string,
+  state: ToolStatus,
+  output = "",
+  command = `echo ${id}`,
+): Omit<ToolPart, "sessionID" | "messageID"> {
+  if (state === "pending") return toolPart(id, "bash", state, { command })
+  if (state === "running")
+    return toolPart(id, "bash", state, { command }, { title: command, metadata: { command, output } })
+  if (state === "error")
+    return toolPart(id, "bash", state, { command }, { error: output || undefined, metadata: { command, output } })
+  return toolPart(id, "bash", state, { command }, { title: command, output, metadata: { command, output } })
+}
+
+export function completedAssistantInfo(info: AssistantMessage): AssistantMessage {
+  return { ...info, time: { ...info.time, completed: 1700000003000 } }
+}
+
+export function project() {
+  return {
+    id: projectID,
+    worktree: directory,
+    vcs: "git",
+    name: "timeline-stability",
+    time: { created: 1700000000000, updated: 1700000000000 },
+    sandboxes: [],
+  }
+}
+
+export function session(input: Partial<Session> = {}): Session {
+  return {
+    id: sessionID,
+    slug: "timeline-stability",
+    projectID,
+    directory,
+    title,
+    version: "dev",
+    time: { created: 1700000000000, updated: 1700000000000 },
+    ...input,
+  }
+}
+
+function eventSchema<
+  const Type extends TimelinePayload["type"],
+  const Properties extends Schema.Codec<unknown, unknown>,
+>(type: Type, properties: Properties) {
+  return Schema.Struct({
+    directory: Schema.String,
+    project: Schema.optional(Schema.String),
+    workspace: Schema.optional(Schema.String),
+    payload: Schema.Struct({ id: Event.ID, type: Schema.Literal(type), properties }),
+  })
+}
+
+function provider() {
+  return {
+    all: [
+      {
+        id: "opencode",
+        name: "OpenCode",
+        models: { "claude-opus-4-6": { id: "claude-opus-4-6", name: "Claude Opus 4.6", limit: { context: 200_000 } } },
+      },
+    ],
+    connected: ["opencode"],
+    default: { providerID: "opencode", modelID: "claude-opus-4-6" },
+  }
+}

packages/app/e2e/performance/timeline-stability/interaction.spec.ts

@@ -0,0 +1,242 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import { assistantMessage, setupTimeline, shell, textPart, toolPart, userMessage, waitForVisualSettle } from "./fixture"
+
+test("expands and collapses a long completed shell without overlap", async ({ page }, testInfo) => {
+  const shellID = "prt_interaction_01_shell"
+  const followingID = "prt_interaction_02_following"
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([shell(shellID, "completed", lines(50)), textPart(followingID, "Following shell expansion")]),
+    ],
+    settings: { shellToolPartsExpanded: false },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  const trigger = page.locator(`[data-timeline-part-id="${shellID}"] [data-slot="collapsible-trigger"]`)
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${shellID}"]`, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  const plan = visualPlan(regions, [
+    { type: "required", regions: ["shell", "following"] },
+    { type: "unique", regions: ["shell", "following"] },
+    { type: "stable", regions: ["shell", "following"] },
+    { type: "opacity", regions: "all" },
+    { type: "continuity", regions: "all" },
+    { type: "motion", regions: "all", maxPositionReversals: 0 },
+    { type: "label-stability", regions: "all" },
+    { type: "preserve-bottom-anchor" },
+    { type: "flow", regions: ["shell", "following"] },
+  ])
+  await startVisualProbe(page, regions)
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await page.waitForTimeout(500)
+  const expanded = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "shell-expand", expanded, plan)
+
+  await startVisualProbe(page, regions)
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+  await page.waitForTimeout(500)
+  const collapsed = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "shell-collapse", collapsed, plan)
+})
+
+test("expands and collapses a completed context group without overlap", async ({ page }, testInfo) => {
+  const ids = [
+    "prt_interaction_01_read",
+    "prt_interaction_02_glob",
+    "prt_interaction_03_grep",
+    "prt_interaction_04_list",
+  ]
+  const group = `[data-timeline-part-ids="${ids.join(",")}"]`
+  const followingID = "prt_interaction_context_following"
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(ids[0]!, "read", "completed", { filePath: "src/a.ts" }),
+        toolPart(ids[1]!, "glob", "completed", { path: ".", pattern: "**/*.ts" }),
+        toolPart(ids[2]!, "grep", "completed", { path: ".", pattern: "stable" }),
+        toolPart(ids[3]!, "list", "completed", { path: "src" }),
+        textPart(followingID, "Following context expansion"),
+      ]),
+    ],
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  const trigger = page.locator(`${group} [data-slot="collapsible-trigger"]`)
+  await waitForVisualSettle(page, [group, `[data-timeline-part-id="${followingID}"]`])
+  for (const [name, expanded] of [
+    ["context-expand", true],
+    ["context-collapse", false],
+    ["context-reexpand", true],
+  ] as const) {
+    const regions = defineVisualRegions({
+      context: { selector: group, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    await trigger.click()
+    await expect(trigger).toHaveAttribute("aria-expanded", String(expanded))
+    await page.waitForTimeout(500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      name,
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: ["context", "following"] },
+        { type: "unique", regions: ["context", "following"] },
+        { type: "stable", regions: ["context", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["context", "following"] },
+      ]),
+    )
+  }
+})
+
+test("expands and collapses an edit diff without moving twice", async ({ page }, testInfo) => {
+  const editID = "prt_interaction_edit"
+  const followingID = "prt_interaction_edit_following"
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(
+          editID,
+          "edit",
+          "completed",
+          { filePath: "src/edit.ts" },
+          {
+            metadata: {
+              filediff: {
+                file: "src/edit.ts",
+                additions: 40,
+                deletions: 40,
+                before: source(40, false),
+                after: source(40, true),
+              },
+            },
+          },
+        ),
+        textPart(followingID, "Following edit expansion"),
+      ]),
+    ],
+    settings: { editToolPartsExpanded: false },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  const trigger = page.locator(`[data-timeline-part-id="${editID}"] [data-slot="collapsible-trigger"]`).first()
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${editID}"]`, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    edit: { selector: `[data-timeline-part-id="${editID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await page.waitForTimeout(900)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "edit-expand",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["edit", "following"] },
+      { type: "unique", regions: ["edit", "following"] },
+      { type: "stable", regions: ["edit", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0, maxReversals: 1 },
+      { type: "label-stability", regions: "all" },
+      { type: "preserve-bottom-anchor" },
+      { type: "flow", regions: ["edit", "following"] },
+    ]),
+  )
+})
+
+test("shows all and expands historical diff summary without overlap", async ({ page }, testInfo) => {
+  const firstUser = userMessage(undefined, {
+    summary: {
+      diffs: Array.from({ length: 12 }, (_, index) => ({
+        file: `src/diff-${index}.ts`,
+        additions: 1,
+        deletions: 1,
+        patch: `@@ -1 +1 @@\n-export const value = ${index}\n+export const value = ${index + 1}`,
+      })),
+    },
+  })
+  const nextUserID = "msg_2000_diff_interaction_user"
+  await setupTimeline(page, {
+    messages: [
+      firstUser,
+      assistantMessage(),
+      userMessage(undefined, { id: nextUserID, created: 1700000010000 }),
+      assistantMessage([], {
+        id: "msg_2001_diff_interaction_assistant",
+        parentID: nextUserID,
+        created: 1700000011000,
+      }),
+    ],
+    cpuRate: 4,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  await scroller.evaluate((element) => (element.scrollTop = 0))
+  const diff = page.locator('[data-timeline-row="DiffSummary"]')
+  const following = page.locator(`[data-message-id="${nextUserID}"]`).first()
+  await expect(diff).toBeVisible()
+  const regions = defineVisualRegions({
+    diff: { selector: '[data-timeline-row="DiffSummary"]' },
+    following: { selector: `[data-message-id="${nextUserID}"]` },
+  })
+  await startVisualProbe(page, regions)
+  await page.getByText(/show all/i).click()
+  await page.waitForTimeout(500)
+  await diff.locator('[data-slot="session-turn-diff-trigger"]').first().click()
+  await page.waitForTimeout(900)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "diff-summary-expand",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["diff", "following"] },
+      { type: "unique", regions: ["diff", "following"] },
+      { type: "stable", regions: ["diff", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 1, maxReversals: 2 },
+      { type: "label-stability", regions: "all" },
+      { type: "flow", regions: ["diff", "following"] },
+    ]),
+  )
+})
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}
+
+function source(count: number, changed: boolean) {
+  return Array.from(
+    { length: count },
+    (_, index) => `export const value${index} = ${changed ? index + 1 : index}\n`,
+  ).join("")
+}

packages/app/e2e/performance/timeline-stability/lifecycle.spec.ts

@@ -0,0 +1,157 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  mapVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  completedAssistantInfo,
+  messageUpdated,
+  partDelta,
+  partUpdated,
+  reasoningPart,
+  setupTimeline,
+  shell,
+  status,
+  textPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+test.describe("timeline visual lifecycle stability", () => {
+  test("streams empty, short, and long parallel shells to staggered completion", async ({ page }, testInfo) => {
+    test.setTimeout(180_000)
+    const ids = ["prt_parallel_01_empty", "prt_parallel_02_short", "prt_parallel_03_long"] as const
+    const initial = ids.map((id) => shell(id, "running"))
+    const followingID = "prt_parallel_04_following"
+    const assistant = assistantMessage([...initial, textPart(followingID, "Following all parallel shells.")], {
+      completed: false,
+    })
+    const timeline = await setupTimeline(page, {
+      messages: [userMessage(), assistant],
+      settings: { shellToolPartsExpanded: true, showReasoningSummaries: true },
+      cpuRate: 4,
+      eventRetry: 24,
+      seedHistory: true,
+    })
+    await timeline.send(status("busy"), 150)
+    for (const id of ids) await timeline.waitForPart(id)
+    const scroller = page.locator(".scroll-view__viewport", {
+      has: page.locator('[data-timeline-row="AssistantPart"]'),
+    })
+    await scroller.evaluate((element) => (element.scrollTop = element.scrollHeight))
+    const regions = defineVisualRegions({
+      prt_shell_empty: shellRegion(ids[0]),
+      prt_shell_short: shellRegion(ids[1]),
+      prt_shell_long: shellRegion(ids[2]),
+      following: shellRegion(followingID),
+    })
+    await waitForVisualSettle(page, [`[data-timeline-part-id="${followingID}"]`])
+    await startVisualProbe(page, regions)
+    await timeline.sendAll([
+      { event: partUpdated(shell(ids[0]!, "completed", "")), delay: 180 },
+      { event: partUpdated(shell(ids[2]!, "running", lines(10))), delay: 70 },
+      { event: partUpdated(shell(ids[1]!, "running", lines(2))), delay: 110 },
+      { event: partUpdated(shell(ids[2]!, "running", lines(25))), delay: 80 },
+      { event: partUpdated(shell(ids[1]!, "completed", lines(2))), delay: 260 },
+      { event: partUpdated(shell(ids[2]!, "running", lines(50))), delay: 100 },
+      { event: partUpdated(shell(ids[2]!, "completed", lines(50))), delay: 450 },
+      { event: messageUpdated(completedAssistantInfo(assistant.info)), delay: 100 },
+      { event: status("idle"), delay: 700 },
+    ])
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "parallel-shells",
+      trace,
+      visualPlan(
+        regions,
+        [
+          { type: "required", regions: ["prt_shell_empty", "prt_shell_short", "prt_shell_long", "following"] },
+          { type: "unique", regions: ["prt_shell_empty", "prt_shell_short", "prt_shell_long"] },
+          { type: "stable", regions: ["prt_shell_empty", "prt_shell_short", "prt_shell_long", "following"] },
+          { type: "opacity", regions: "all" },
+          { type: "continuity", regions: "all" },
+          { type: "motion", regions: "all", maxPositionReversals: 0, maxReversals: 4 },
+          { type: "label-stability", regions: "all" },
+          { type: "preserve-bottom-anchor" },
+          { type: "flow", regions: ["prt_shell_empty", "prt_shell_short", "prt_shell_long", "following"] },
+        ],
+        { perMarker: true },
+      ),
+    )
+    await expect(page.locator(`[data-timeline-part-id="${ids[2]}"] [data-slot="bash-pre"]`)).toContainText("line 50")
+
+    const short = page.locator(`[data-timeline-part-id="${ids[1]}"]`)
+    await short.locator('[data-slot="collapsible-trigger"]').click()
+    await expect(short.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "false")
+    await timeline.send(partUpdated(textPart("prt_late_sibling", "A later sibling rerender.")), 250)
+    await expect(short.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "false")
+  })
+
+  test("replaces thinking with streamed reasoning and text without a blank visible turn", async ({
+    page,
+  }, testInfo) => {
+    const reasoningID = "prt_reasoning_visible"
+    const textID = "prt_streamed_text"
+    const assistant = assistantMessage([], { completed: false })
+    const timeline = await setupTimeline(page, {
+      messages: [userMessage(), assistant],
+      settings: { showReasoningSummaries: true },
+      cpuRate: 4,
+    })
+    await timeline.send(status("busy"), 120)
+    await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+
+    const regions = defineVisualRegions({
+      thinking: { selector: '[data-timeline-row="Thinking"]' },
+      reasoning: {
+        selector: `[data-timeline-part-id="${reasoningID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+      text: { selector: `[data-timeline-part-id="${textID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    })
+    await startVisualProbe(page, regions)
+    await timeline.send(partUpdated(reasoningPart(reasoningID, "")), 100)
+    await expect(page.locator(`[data-timeline-part-id="${reasoningID}"]`)).toHaveCount(0)
+    await timeline.send(partUpdated(reasoningPart(reasoningID, "## Planning\n\nChecking the visible timeline.")), 160)
+    await timeline.waitForPart(reasoningID)
+    await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+    await timeline.send(partUpdated(textPart(textID, "Starting")), 100)
+    await timeline.send(partDelta(textID, " **stable"), 90)
+    await timeline.send(partDelta(textID, " output** with `code` and [a link"), 130)
+    await timeline.send(partDelta(textID, "](https://example.com)."), 220)
+    await timeline.send(messageUpdated(completedAssistantInfo(assistant.info)), 120)
+    await timeline.send(status("idle"), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "reasoning-text-handoff",
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: ["reasoning", "text"] },
+        { type: "continuous-any", regions: ["thinking", "reasoning", "text"] },
+        { type: "unique", regions: ["reasoning", "text"] },
+        { type: "stable", regions: ["reasoning", "text"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxReversals: 4 },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["reasoning", "text"] },
+      ]),
+    )
+    await expect(page.locator(`[data-timeline-part-id="${textID}"]`)).toContainText("stable output")
+  })
+})
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}
+
+function shellRegion(id: string) {
+  return { selector: `[data-timeline-part-id="${id}"]`, closest: '[data-timeline-row="AssistantPart"]' }
+}

packages/app/e2e/performance/timeline-stability/oracle-browser.spec.ts

@@ -0,0 +1,75 @@
+import { expect, test } from "@playwright/test"
+import {
+  analyzeVisualObservations,
+  defineVisualRegions,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import { assistantMessage, setupTimeline, textPart, userMessage } from "./fixture"
+
+test("detects blanking caused by ancestor opacity", async ({ page }) => {
+  const partID = "prt_oracle_ancestor_opacity"
+  await setupTimeline(page, { messages: [userMessage(), assistantMessage([textPart(partID, "Visible content")])] })
+  const row = page.locator(`[data-timeline-part-id="${partID}"]`).first()
+  const regions = defineVisualRegions({
+    content: { selector: `[data-timeline-part-id="${partID}"]` },
+  })
+  await startVisualProbe(page, regions)
+  await row.evaluate((element) => {
+    element.parentElement!.style.opacity = "0"
+  })
+  await page.waitForTimeout(50)
+  await row.evaluate((element) => {
+    element.parentElement!.style.opacity = "1"
+  })
+  await page.waitForTimeout(50)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  const issues = analyzeVisualObservations(
+    trace.samples,
+    visualPlan(regions, [
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all" },
+      { type: "label-stability", regions: "all" },
+    ]),
+  )
+
+  expect(issues.some((issue) => issue.includes("blanked between visible frames"))).toBe(true)
+})
+
+test("detects root opacity when probing descendant opacity", async ({ page }) => {
+  const partID = "prt_oracle_descendant_opacity"
+  await setupTimeline(page, { messages: [userMessage(), assistantMessage([textPart(partID, "Visible content")])] })
+  const row = page.locator(`[data-timeline-part-id="${partID}"]`).first()
+  await row.evaluate((element) => {
+    element.innerHTML = '<span data-probe-opacity="true">Visible content</span>'
+  })
+  const regions = defineVisualRegions({
+    content: {
+      selector: `[data-timeline-part-id="${partID}"]`,
+      opacitySelectors: ['[data-probe-opacity="true"]'],
+    },
+  })
+  await startVisualProbe(page, regions)
+  await row.evaluate((element) => {
+    ;(element as HTMLElement).style.opacity = "0"
+  })
+  await page.waitForTimeout(50)
+  await row.evaluate((element) => {
+    ;(element as HTMLElement).style.opacity = "1"
+  })
+  await page.waitForTimeout(50)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  const issues = analyzeVisualObservations(
+    trace.samples,
+    visualPlan(regions, [
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all" },
+      { type: "label-stability", regions: "all" },
+    ]),
+  )
+
+  expect(issues.some((issue) => issue.includes("blanked between visible frames"))).toBe(true)
+})

packages/app/e2e/performance/timeline-stability/playwright.config.ts

@@ -0,0 +1,17 @@
+import config from "../playwright.config"
+
+export default {
+  ...config,
+  testDir: ".",
+  testMatch: "**/*.spec.ts",
+  outputDir: "../../test-results/timeline-stability",
+  reporter: [["html", { outputFolder: "../../playwright-report/timeline-stability", open: "never" }], ["line"]],
+  retries: 0,
+  workers: 1,
+  use: {
+    ...config.use,
+    trace: "retain-on-failure",
+    screenshot: "only-on-failure",
+    video: "retain-on-failure",
+  },
+}

packages/app/e2e/performance/timeline-stability/scroll-interaction.spec.ts

@@ -0,0 +1,353 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  shell,
+  textPart,
+  userMessage,
+  type TimelineMessage,
+} from "./fixture"
+
+test("does not reverse visible rows when the user wheels during shell remeasurement", async ({ page }, testInfo) => {
+  const shellID = "prt_wheel_01_shell"
+  const followingID = "prt_wheel_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      ...history(12),
+      userMessage(),
+      assistantMessage([shell(shellID, "running"), textPart(followingID, "Following wheel interaction")], {
+        completed: false,
+      }),
+    ],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+    reducedMotion: true,
+    seedHistory: true,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(shell(shellID, "running", lines(30))), 80)
+  await scroller.evaluate((element) =>
+    element.dispatchEvent(new WheelEvent("wheel", { bubbles: true, cancelable: true, deltaY: -180 })),
+  )
+  await scroller.evaluate((element) => (element.scrollTop -= 180))
+  await timeline.send(partUpdated(shell(shellID, "running", lines(50))), 250)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "wheel-during-resize", trace, rowPairPlan(regions, 1))
+})
+
+test("keeps moving upward while drag-selecting above the timeline", async ({ page }) => {
+  await setupTimeline(page, {
+    messages: history(80),
+    viewport: { width: 1400, height: 700 },
+    reducedMotion: true,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  const text = page.getByText("History 79.", { exact: false })
+  await expect(text).toBeVisible()
+  await scroller.evaluate((element) => {
+    element.dataset.selectionLength = "0"
+    document.addEventListener("selectionchange", () => {
+      element.dataset.selectionLength = String(
+        Math.max(Number(element.dataset.selectionLength), window.getSelection()?.toString().length ?? 0),
+      )
+    })
+  })
+  const textBox = await text.boundingBox()
+  const scrollBox = await scroller.boundingBox()
+  expect(textBox).not.toBeNull()
+  expect(scrollBox).not.toBeNull()
+  if (!textBox || !scrollBox) return
+
+  await page.mouse.move(textBox.x + textBox.width - 10, textBox.y + textBox.height / 2)
+  await page.mouse.down()
+  await page.mouse.move(textBox.x + 20, scrollBox.y - 120, { steps: 30 })
+
+  await expect.poll(() => scroller.evaluate((element) => Number(element.dataset.selectionLength))).toBeGreaterThan(0)
+  await expect
+    .poll(() => scroller.evaluate((element) => element.scrollHeight - element.clientHeight - element.scrollTop))
+    .toBeGreaterThan(500)
+  await page.mouse.up()
+})
+
+test("does not pull a keyboard-scrolled user during shell remeasurement", async ({ page }, testInfo) => {
+  const shellID = "prt_keyboard_01_shell"
+  const followingID = "prt_keyboard_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      ...history(12),
+      userMessage(),
+      assistantMessage([shell(shellID, "running"), textPart(followingID, "Following keyboard interaction")], {
+        completed: false,
+      }),
+    ],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  await scroller.focus()
+  for (let index = 0; index < 3; index++) {
+    await scroller.press("PageUp")
+    await page.waitForTimeout(250)
+  }
+  await expect
+    .poll(() => scroller.evaluate((element) => element.scrollHeight - element.clientHeight - element.scrollTop), {
+      timeout: 20_000,
+    })
+    .toBeGreaterThan(80)
+  await page.waitForFunction(() => {
+    const root = [...document.querySelectorAll<HTMLElement>(".scroll-view__viewport")].find((element) =>
+      element.querySelector("[data-timeline-row]"),
+    )
+    if (!root) return false
+    return new Promise<boolean>((resolve) => {
+      const top = root.scrollTop
+      requestAnimationFrame(() => requestAnimationFrame(() => resolve(Math.abs(root.scrollTop - top) <= 0.5)))
+    })
+  })
+  const anchor = await scroller.evaluate((element) => {
+    const view = element.getBoundingClientRect()
+    return [...element.querySelectorAll<HTMLElement>("[data-timeline-key]")].find((row) => {
+      const rect = row.getBoundingClientRect()
+      return rect.top >= view.top + 40 && rect.bottom <= view.bottom - 40
+    })?.dataset.timelineKey
+  })
+  expect(anchor).toBeTruthy()
+  const regions = defineVisualRegions({
+    anchor: { selector: `[data-timeline-key="${anchor}"]` },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(shell(shellID, "running", lines(50))), 400)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "keyboard-during-resize", trace, anchorPlan(regions))
+})
+
+test("tracks keyboard scrolling from a focused timeline descendant", async ({ page }, testInfo) => {
+  const shellID = "prt_descendant_keyboard_01_shell"
+  const timeline = await setupTimeline(page, {
+    messages: [...history(12), userMessage(), assistantMessage([shell(shellID, "completed", lines(5))])],
+    settings: { shellToolPartsExpanded: false },
+    cpuRate: 4,
+    reducedMotion: true,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  const row = page.locator(`[data-timeline-part-id="${shellID}"]`).first()
+  const trigger = page.locator(`[data-timeline-part-id="${shellID}"] [data-slot="collapsible-trigger"]`)
+  await row.evaluate((element) => element.setAttribute("tabindex", "0"))
+  await row.focus()
+  for (let index = 0; index < 3; index++) {
+    await row.press("PageUp")
+    await page.waitForTimeout(250)
+  }
+  await expect
+    .poll(() => scroller.evaluate((element) => element.scrollHeight - element.clientHeight - element.scrollTop))
+    .toBeGreaterThan(5)
+  const anchor = await scroller.evaluate((element) => {
+    const view = element.getBoundingClientRect()
+    return [...element.querySelectorAll<HTMLElement>("[data-timeline-key]")].find((row) => {
+      const rect = row.getBoundingClientRect()
+      return rect.top >= view.top + 40 && rect.bottom <= view.bottom - 40
+    })?.dataset.timelineKey
+  })
+  expect(anchor).toBeTruthy()
+  const regions = defineVisualRegions({
+    anchor: { selector: `[data-timeline-key="${anchor}"]` },
+  })
+  await startVisualProbe(page, regions)
+  await trigger.click()
+  await page.waitForTimeout(300)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "descendant-keyboard-resize", trace, anchorPlan(regions))
+})
+
+test("does not claim keyboard scrolling owned by a nested scrollable", async ({ page }) => {
+  const shellID = "prt_nested_keyboard_shell"
+  await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([shell(shellID, "completed", lines(50))])],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+    reducedMotion: true,
+    seedHistory: true,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  const nested = page.locator(`[data-timeline-part-id="${shellID}"] [data-scrollable]`)
+  await nested.evaluate((element) => (element.scrollTop = element.scrollHeight))
+  await nested.focus()
+  await page.waitForFunction(() => {
+    const root = [...document.querySelectorAll<HTMLElement>(".scroll-view__viewport")].find((element) =>
+      element.querySelector("[data-timeline-row]"),
+    )
+    if (!root) return false
+    return new Promise<boolean>((resolve) => {
+      const top = root.scrollTop
+      requestAnimationFrame(() => requestAnimationFrame(() => resolve(Math.abs(root.scrollTop - top) <= 0.5)))
+    })
+  })
+  const before = await scroller.evaluate((element) => element.scrollTop)
+  const nestedBefore = await nested.evaluate((element) => element.scrollTop)
+  await nested.press("PageUp")
+  await page.waitForTimeout(300)
+  expect(await scroller.evaluate((element) => element.scrollTop)).toBe(before)
+  expect(await nested.evaluate((element) => element.scrollTop)).toBeLessThan(nestedBefore)
+
+  await nested.evaluate((element) => (element.scrollTop = 0))
+  await scroller.evaluate((element) => (element.scrollTop = Math.min(300, element.scrollHeight - element.clientHeight)))
+  const boundaryBefore = await scroller.evaluate((element) => element.scrollTop)
+  expect(boundaryBefore).toBeGreaterThan(0)
+  await nested.press("PageUp")
+  await expect.poll(() => scroller.evaluate((element) => element.scrollTop)).toBeLessThan(boundaryBefore)
+
+  const nonOverflowing = page.locator(`[data-timeline-part-id="${shellID}"]`).first()
+  await nonOverflowing.evaluate((element) => {
+    element.setAttribute("data-scrollable", "")
+    element.setAttribute("tabindex", "0")
+  })
+  await nonOverflowing.focus()
+  const nonOverflowBefore = await scroller.evaluate((element) => element.scrollTop)
+  await nonOverflowing.press("PageUp")
+  await expect.poll(() => scroller.evaluate((element) => element.scrollTop)).toBeLessThan(nonOverflowBefore)
+})
+
+test("jump to latest lands on stable final rows after offscreen growth", async ({ page }, testInfo) => {
+  const shellID = "prt_jump_01_shell"
+  const followingID = "prt_jump_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      ...history(20),
+      userMessage(),
+      assistantMessage([shell(shellID, "running"), textPart(followingID, "Latest visible row")], { completed: false }),
+    ],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  await scroller.evaluate(
+    (element) => (element.scrollTop = Math.max(0, element.scrollHeight - element.clientHeight - 600)),
+  )
+  await timeline.send(partUpdated(shell(shellID, "running", lines(50))), 300)
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await page.getByRole("button", { name: /Jump to latest/i }).click()
+  await expect(page.locator(`[data-timeline-part-id="${followingID}"]`)).toBeVisible()
+  await page.waitForTimeout(600)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "jump-latest",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["shell", "following"] },
+      { type: "unique", regions: ["shell", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 1 },
+      { type: "label-stability", regions: "all" },
+      { type: "acquire-bottom-anchor" },
+      { type: "flow", regions: ["shell", "following"] },
+    ]),
+  )
+})
+
+test("handles a single row taller than the viewport", async ({ page }, testInfo) => {
+  const shellID = "prt_tall_01_shell"
+  const followingID = "prt_tall_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([shell(shellID, "running"), textPart(followingID, "After tall row")], { completed: false }),
+    ],
+    settings: { shellToolPartsExpanded: true },
+    viewport: { width: 900, height: 360 },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(shell(shellID, "completed", lines(100))), 700)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "taller-than-viewport",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["shell", "following"] },
+      { type: "unique", regions: ["shell", "following"] },
+      { type: "stable", regions: ["shell", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0 },
+      { type: "label-stability", regions: "all" },
+      { type: "preserve-bottom-anchor" },
+      { type: "flow", regions: ["shell", "following"] },
+    ]),
+  )
+})
+
+function history(count: number): TimelineMessage[] {
+  return Array.from({ length: count }, (_, index) => {
+    const prefix = `msg_${String(index).padStart(4, "0")}_scroll`
+    const userID = `${prefix}_a_user`
+    return [
+      userMessage(undefined, { id: userID, created: 1690000000000 + index * 10_000 }),
+      assistantMessage(
+        [textPart(`prt_${String(index).padStart(4, "0")}_scroll`, `History ${index}. ${"content ".repeat(30)}`)],
+        {
+          id: `${prefix}_b_assistant`,
+          parentID: userID,
+          created: 1690000001000 + index * 10_000,
+        },
+      ),
+    ]
+  }).flat()
+}
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}
+
+function rowPairPlan(
+  regions: Record<"shell" | "following", { selector: string; closest?: string }>,
+  maxPositionReversals: number,
+) {
+  return visualPlan(regions, [
+    { type: "required", regions: ["shell", "following"] },
+    { type: "unique", regions: ["shell", "following"] },
+    { type: "stable", regions: ["shell", "following"] },
+    { type: "opacity", regions: "all" },
+    { type: "continuity", regions: "all" },
+    { type: "motion", regions: "all", maxPositionReversals },
+    { type: "label-stability", regions: "all" },
+    { type: "flow", regions: ["shell", "following"] },
+  ])
+}
+
+function anchorPlan(regions: Record<"anchor", { selector: string; closest?: string }>) {
+  return visualPlan(regions, [
+    { type: "required", regions: ["anchor"] },
+    { type: "unique", regions: ["anchor"] },
+    { type: "stable", regions: ["anchor"] },
+    { type: "fixed", regions: ["anchor"] },
+    { type: "opacity", regions: "all" },
+    { type: "continuity", regions: "all" },
+    { type: "motion", regions: "all", maxPositionReversals: 0 },
+    { type: "label-stability", regions: "all" },
+  ])
+}

packages/app/e2e/performance/timeline-stability/shell-matrix.spec.ts

@@ -0,0 +1,255 @@
+import { test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  shell,
+  textPart,
+  userMessage,
+  waitForVisualSettle,
+} from "./fixture"
+
+const profiles = [
+  {
+    name: "empty running to completed",
+    updates: [{ state: "completed" as const, output: "", delay: 350 }],
+  },
+  {
+    name: "50 lines arriving incrementally",
+    updates: [
+      { state: "running" as const, output: lines(1), delay: 100 },
+      { state: "running" as const, output: lines(10), delay: 160 },
+      { state: "running" as const, output: lines(25), delay: 90 },
+      { state: "running" as const, output: lines(50), delay: 220 },
+      { state: "completed" as const, output: lines(50), delay: 500 },
+    ],
+  },
+  {
+    name: "wide ANSI and CRLF output",
+    updates: [
+      {
+        state: "running" as const,
+        output: Array.from({ length: 20 }, (_, index) => `\u001b[32mline ${index}\u001b[0m ${"wide-".repeat(30)}`).join(
+          "\r\n",
+        ),
+        delay: 240,
+      },
+      {
+        state: "completed" as const,
+        output: Array.from({ length: 20 }, (_, index) => `line ${index} ${"wide-".repeat(30)}`).join("\n"),
+        delay: 500,
+      },
+    ],
+  },
+] as const
+
+for (const profile of profiles) {
+  test(`keeps rows stable for shell ${profile.name}`, async ({ page }, testInfo) => {
+    const shellID = `prt_matrix_${profiles.indexOf(profile)}_01_shell`
+    const followingID = `prt_matrix_${profiles.indexOf(profile)}_02_following`
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([shell(shellID, "running"), textPart(followingID, "Following shell row")], {
+          completed: false,
+        }),
+      ],
+      settings: { shellToolPartsExpanded: true },
+      cpuRate: 4,
+      seedHistory: true,
+    })
+    const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+    await scroller.evaluate((element) => (element.scrollTop = element.scrollHeight))
+    await waitForVisualSettle(page, [
+      `[data-timeline-part-id="${shellID}"]`,
+      `[data-timeline-part-id="${followingID}"]`,
+    ])
+    const regions = defineVisualRegions({
+      shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    for (const update of profile.updates) {
+      await timeline.send(partUpdated(shell(shellID, update.state, update.output)), update.delay)
+    }
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      `shell-${profiles.indexOf(profile)}`,
+      trace,
+      visualPlan(
+        regions,
+        [
+          { type: "required", regions: ["shell", "following"] },
+          { type: "unique", regions: ["shell", "following"] },
+          { type: "stable", regions: ["shell", "following"] },
+          { type: "opacity", regions: "all" },
+          { type: "continuity", regions: "all" },
+          { type: "motion", regions: "all", maxPositionReversals: 0, maxReversals: 1 },
+          { type: "label-stability", regions: "all" },
+          { type: "preserve-bottom-anchor" },
+          { type: "flow", regions: ["shell", "following"] },
+        ],
+        { perMarker: true },
+      ),
+    )
+  })
+}
+
+test("keeps following row stable when a collapsed shell receives 50 lines", async ({ page }, testInfo) => {
+  const shellID = "prt_matrix_collapsed_01_shell"
+  const followingID = "prt_matrix_collapsed_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([shell(shellID, "running"), textPart(followingID, "Following collapsed shell")], {
+        completed: false,
+      }),
+    ],
+    settings: { shellToolPartsExpanded: false },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${shellID}"]`, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(shell(shellID, "running", lines(50))), 240)
+  await timeline.send(partUpdated(shell(shellID, "completed", lines(50))), 500)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "collapsed-shell",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["shell", "following"] },
+        { type: "unique", regions: ["shell", "following"] },
+        { type: "stable", regions: ["shell", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: ["following"], maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["shell", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+test("keeps rows stable when a running shell becomes an error", async ({ page }, testInfo) => {
+  const shellID = "prt_matrix_error_01_shell"
+  const followingID = "prt_matrix_error_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([shell(shellID, "running", lines(10)), textPart(followingID, "Following failed shell")], {
+        completed: false,
+      }),
+    ],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${shellID}"]`, `[data-timeline-part-id="${followingID}"]`])
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    partUpdated({
+      ...shell(shellID, "error"),
+      state: {
+        status: "error",
+        input: { command: `echo ${shellID}` },
+        error: "Command failed after output",
+        metadata: {},
+        time: { start: 1700000001000, end: 1700000002000 },
+      },
+    }),
+    500,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "shell-error",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["shell", "following"] },
+        { type: "unique", regions: ["shell", "following"] },
+        { type: "stable", regions: ["shell", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: ["following"], maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["shell", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+test("keeps rows stable when later text arrives before shell output", async ({ page }, testInfo) => {
+  const shellID = "prt_late_text_01_shell"
+  const followingID = "prt_late_text_02_following"
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([shell(shellID, "running")], { completed: false })],
+    settings: { shellToolPartsExpanded: true },
+    cpuRate: 4,
+    seedHistory: true,
+  })
+  await waitForVisualSettle(page, [`[data-timeline-part-id="${shellID}"]`])
+  const regions = defineVisualRegions({
+    shell: { selector: `[data-timeline-part-id="${shellID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: {
+      selector: `[data-timeline-part-id="${followingID}"]`,
+      closest: '[data-timeline-row="AssistantPart"]',
+    },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(textPart(followingID, "Later assistant content arrived before shell output.")), 240)
+  await timeline.send(partUpdated(shell(shellID, "running", lines(20))), 300)
+  await timeline.send(partUpdated(shell(shellID, "completed", lines(20))), 600)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "late-text-before-shell-output",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["shell", "following"] },
+        { type: "unique", regions: ["shell", "following"] },
+        { type: "stable", regions: ["shell"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "preserve-bottom-anchor" },
+        { type: "flow", regions: ["shell", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}

packages/app/e2e/performance/timeline-stability/tool-mutation.spec.ts

@@ -0,0 +1,106 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  partUpdated,
+  session,
+  sessionID,
+  setupTimeline,
+  textPart,
+  toolPart,
+  userMessage,
+} from "./fixture"
+
+test("adds a task child-session link without replacing the task row", async ({ page }, testInfo) => {
+  const taskID = "prt_task_link"
+  const childID = "ses_task_child"
+  const input = { description: "Inspect child", subagent_type: "explore" }
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([toolPart(taskID, "task", "running", input)], { completed: false })],
+    sessions: [session(), session({ id: childID, parentID: sessionID, title: "Inspect child" })],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    task: { selector: `[data-timeline-part-id="${taskID}"] [data-slot="collapsible-trigger"]` },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    partUpdated(toolPart(taskID, "task", "completed", input, { metadata: { sessionId: childID } })),
+    500,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "task-link",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["task"] },
+      { type: "unique", regions: ["task"] },
+      { type: "stable", regions: ["task"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 0 },
+      { type: "label-stability", regions: "all" },
+    ]),
+  )
+  await expect(
+    page.locator(`a[href$="/session/${childID}"]`, { has: page.locator('[data-component="task-tool-card"]') }),
+  ).toBeVisible()
+})
+
+test("changes generic tool arguments without replacing the row", async ({ page }, testInfo) => {
+  const toolID = "prt_generic_mutation"
+  const followingID = "prt_generic_mutation_following"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage(
+        [
+          toolPart(toolID, "mcp_probe", "running", { target: "one", count: 1 }),
+          textPart(followingID, "Following generic tool"),
+        ],
+        { completed: false },
+      ),
+    ],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    tool: { selector: `[data-timeline-part-id="${toolID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    partUpdated(toolPart(toolID, "mcp_probe", "running", { target: "two", count: 2, mode: "deep" })),
+    200,
+  )
+  await timeline.send(
+    partUpdated(toolPart(toolID, "mcp_probe", "completed", { target: "two", count: 2, mode: "deep" })),
+    400,
+  )
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "generic-mutation",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["tool", "following"] },
+        { type: "unique", regions: ["tool", "following"] },
+        { type: "stable", regions: ["tool", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["tool", "following"] },
+      ],
+      { perMarker: true },
+    ),
+  )
+})

packages/app/e2e/performance/timeline-stability/tools.spec.ts

@@ -0,0 +1,198 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantMessage,
+  directory,
+  partUpdated,
+  session,
+  sessionID,
+  setupTimeline,
+  status,
+  textPart,
+  toolPart,
+  userMessage,
+} from "./fixture"
+
+test.describe("timeline tool state stability", () => {
+  test("moves lightweight tools through pending, running, and completed without replacing rows", async ({
+    page,
+  }, testInfo) => {
+    const ids = ["webfetch", "websearch", "task", "skill", "custom"] as const
+    const inputs = {
+      webfetch: { url: "https://example.com/docs" },
+      websearch: { query: "timeline stability" },
+      task: { description: "Inspect timeline", subagent_type: "explore" },
+      skill: { name: "stability" },
+      custom: { target: "timeline", depth: 2 },
+    }
+    const names = { webfetch: "webfetch", websearch: "websearch", task: "task", skill: "skill", custom: "mcp_probe" }
+    const questionID = "prt_state_question"
+    const todoID = "prt_state_todo"
+    const initial = [
+      ...ids.map((id) => toolPart(`prt_state_${id}`, names[id], "pending", inputs[id])),
+      toolPart(questionID, "question", "pending", questionInput()),
+      toolPart(todoID, "todowrite", "pending", { todos: [{ content: "Hidden", status: "pending" }] }),
+      textPart("prt_state_following", "Following lightweight tools"),
+    ]
+    const childID = "ses_timeline_child"
+    const timeline = await setupTimeline(page, {
+      messages: [userMessage(), assistantMessage(initial, { completed: false })],
+      sessions: [session(), session({ id: childID, parentID: sessionID, title: "Inspect timeline" })],
+      cpuRate: 4,
+    })
+    await timeline.send(status("busy"), 120)
+    for (const id of ids) await timeline.waitForPart(`prt_state_${id}`)
+    await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toHaveCount(0)
+    await expect(page.locator(`[data-timeline-part-id="${todoID}"]`)).toHaveCount(0)
+
+    const regionIDs = [
+      "prt_state_webfetch",
+      "prt_state_websearch",
+      "prt_state_task",
+      "prt_state_skill",
+      "prt_state_custom",
+    ] as const
+    const regions = defineVisualRegions({
+      prt_state_webfetch: toolRegion(regionIDs[0]),
+      prt_state_websearch: toolRegion(regionIDs[1]),
+      prt_state_task: toolRegion(regionIDs[2]),
+      prt_state_skill: toolRegion(regionIDs[3]),
+      prt_state_custom: toolRegion(regionIDs[4]),
+    })
+    await startVisualProbe(page, regions)
+    for (const [index, id] of ids.entries()) {
+      await timeline.send(
+        partUpdated(toolPart(`prt_state_${id}`, names[id], "running", inputs[id])),
+        [80, 240, 100, 360, 140][index],
+      )
+    }
+    for (const [index, id] of ["skill", "webfetch", "custom", "task", "websearch"].entries()) {
+      const key = id as (typeof ids)[number]
+      const metadata = key === "task" ? { sessionId: childID } : key === "websearch" ? { provider: "exa" } : {}
+      const output = key === "websearch" ? "Result https://example.com/result" : "Completed"
+      await timeline.send(
+        partUpdated(toolPart(`prt_state_${key}`, names[key], "completed", inputs[key], { metadata, output })),
+        [110, 70, 280, 130, 420][index],
+      )
+    }
+    await timeline.send(
+      partUpdated(
+        toolPart(questionID, "question", "completed", questionInput(), { metadata: { answers: [["Keep it stable"]] } }),
+      ),
+      350,
+    )
+    await timeline.waitForPart(questionID)
+    await timeline.send(status("idle"), 500)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "lightweight-tools",
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: regionIDs },
+        { type: "unique", regions: regionIDs },
+        { type: "stable", regions: regionIDs },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxReversals: 4 },
+        { type: "label-stability", regions: "all" },
+      ]),
+    )
+    await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toContainText("Keep it stable")
+    await expect(page.locator(`[data-timeline-part-id="${todoID}"]`)).toHaveCount(0)
+    await expect(
+      page.locator(`a[href$="/session/${childID}"]`, { has: page.locator('[data-component="task-tool-card"]') }),
+    ).toBeVisible()
+    await expect(page.getByRole("button", { name: /Exa Web Search/ })).toBeVisible()
+  })
+
+  test("keeps an expanded mixed context group stable through staggered completion and error", async ({
+    page,
+  }, testInfo) => {
+    const ids = ["prt_ctx_01_read", "prt_ctx_02_glob", "prt_ctx_03_grep", "prt_ctx_04_list"]
+    const tools = ["read", "glob", "grep", "list"]
+    const inputs = [
+      { filePath: "src/a.ts", offset: 0, limit: 120 },
+      { path: directory, pattern: "**/*.ts" },
+      { path: directory, pattern: "stability", include: "*.ts" },
+      { path: "src" },
+    ]
+    const context = ids.map((id, index) => toolPart(id, tools[index]!, "pending", inputs[index]!))
+    const timeline = await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([...context, textPart("prt_ctx_following", "Following context")], { completed: false }),
+      ],
+      cpuRate: 4,
+    })
+    await timeline.send(status("busy"), 100)
+    const groupSelector = `[data-timeline-part-ids="${ids.join(",")}"]`
+    const group = page.locator(groupSelector)
+    await expect(group).toBeVisible()
+    await group.locator('[data-slot="collapsible-trigger"]').click()
+    await expect(group.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "true")
+
+    const regions = defineVisualRegions({
+      status: {
+        selector: `${groupSelector} [data-component="tool-status-title"]`,
+        opacitySelectors: ['[data-slot="tool-status-active"]', '[data-slot="tool-status-done"]'],
+      },
+      context: { selector: groupSelector, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: '[data-timeline-part-id="prt_ctx_following"]',
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    for (const [index, delay] of [90, 260, 70, 380].entries()) {
+      await timeline.send(partUpdated(toolPart(ids[index]!, tools[index]!, "running", inputs[index]!)), delay)
+    }
+    await timeline.send(partUpdated(toolPart(ids[1]!, tools[1]!, "completed", inputs[1]!)), 130)
+    await timeline.send(partUpdated(toolPart(ids[3]!, tools[3]!, "completed", inputs[3]!)), 210)
+    await timeline.send(
+      partUpdated(toolPart(ids[0]!, tools[0]!, "error", inputs[0]!, { error: "Read interrupted" })),
+      110,
+    )
+    await timeline.send(partUpdated(toolPart(ids[2]!, tools[2]!, "completed", inputs[2]!)), 250)
+    await expect(group.locator('[data-component="tool-status-title"]')).toHaveAttribute("aria-label", "Explored")
+    await timeline.send(status("idle"), 700)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    await reportVisualStability(
+      testInfo,
+      "mixed-context",
+      trace,
+      visualPlan(regions, [
+        { type: "required", regions: ["context", "following"] },
+        { type: "unique", regions: ["context"] },
+        { type: "stable", regions: ["context"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxReversals: 4 },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["context", "following"] },
+      ]),
+    )
+    await expect(group.locator('[data-component="tool-status-title"]')).toHaveAttribute("aria-label", "Explored")
+    await expect(group.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "true")
+    await group.locator('[data-slot="collapsible-trigger"]').click()
+    await expect(group.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "false")
+    await timeline.send(partUpdated(textPart("prt_ctx_late_sibling", "Later sibling content")), 200)
+    await expect(group.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "false")
+    await group.locator('[data-slot="collapsible-trigger"]').click()
+    await expect(group.locator('[data-slot="collapsible-trigger"]')).toHaveAttribute("aria-expanded", "true")
+  })
+})
+
+function questionInput() {
+  return { questions: [{ header: "Stability", question: "Keep it stable?", options: [] }] }
+}
+
+function toolRegion(id: string) {
+  return { selector: `[data-timeline-part-id="${id}"]`, closest: '[data-timeline-row="AssistantPart"]' }
+}

packages/app/e2e/performance/timeline-stability/transition-matrix.spec.ts

@@ -0,0 +1,272 @@
+import { expect, test } from "@playwright/test"
+import {
+  defineVisualRegions,
+  reportVisualStability,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../../utils/visual-stability"
+import {
+  assistantID,
+  assistantMessage,
+  completedAssistantInfo,
+  event,
+  messageUpdated,
+  partDelta,
+  partUpdated,
+  setupTimeline,
+  shell,
+  status,
+  textPart,
+  toolPart,
+  userMessage,
+} from "./fixture"
+
+test("keeps unchanged siblings stable while a middle part is inserted and removed", async ({ page }, testInfo) => {
+  const firstID = "prt_mutation_01_first"
+  const middleID = "prt_mutation_02_middle"
+  const lastID = "prt_mutation_03_last"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([textPart(firstID, "First stable row"), textPart(lastID, "Last stable row")], {
+        completed: false,
+      }),
+    ],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    first: { selector: `[data-timeline-part-id="${firstID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    last: { selector: `[data-timeline-part-id="${lastID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partUpdated(textPart(middleID, "Inserted middle row. ".repeat(12))), 350)
+  await expect(page.locator(`[data-timeline-part-id="${middleID}"]`)).toBeVisible()
+  await timeline.send(
+    event("message.part.removed", { sessionID: "ses_timeline_stability", messageID: assistantID, partID: middleID }),
+    500,
+  )
+  await expect(page.locator(`[data-timeline-part-id="${middleID}"]`)).toHaveCount(0)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "middle-insert-remove", trace, stablePairPlan(regions, 1))
+})
+
+test("streams text through growth, canonical replacement, and completion", async ({ page }, testInfo) => {
+  const textID = "prt_text_reconcile"
+  const followingID = "prt_text_reconcile_following"
+  const assistant = assistantMessage([textPart(textID, "Starting"), textPart(followingID, "Following text row")], {
+    completed: false,
+  })
+  const timeline = await setupTimeline(page, { messages: [userMessage(), assistant], cpuRate: 4 })
+  const regions = defineVisualRegions({
+    text: { selector: `[data-timeline-part-id="${textID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    following: { selector: `[data-timeline-part-id="${followingID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(partDelta(textID, " streamed content"), 100)
+  await timeline.send(partDelta(textID, "\n\n- item one\n- item two\n- item three"), 180)
+  await timeline.send(partUpdated(textPart(textID, "Canonical replacement with a shorter final paragraph.")), 200)
+  await timeline.send(messageUpdated(completedAssistantInfo(assistant.info)), 500)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "text-reconcile",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["text", "following"] },
+      { type: "unique", regions: ["text", "following"] },
+      { type: "stable", regions: ["text", "following"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all", maxPositionReversals: 1, maxReversals: 2 },
+      { type: "label-stability", regions: "all" },
+      { type: "preserve-bottom-anchor" },
+      { type: "flow", regions: ["text", "following"] },
+    ]),
+  )
+})
+
+test("inserts a completed question between stable rows", async ({ page }, testInfo) => {
+  const firstID = "prt_question_01_first"
+  const questionID = "prt_question_02_hidden"
+  const lastID = "prt_question_03_last"
+  const input = { questions: [{ header: "Choice", question: "Keep stable?", options: [] }] }
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage(
+        [
+          textPart(firstID, "Before question"),
+          toolPart(questionID, "question", "running", input),
+          textPart(lastID, "After question"),
+        ],
+        { completed: false },
+      ),
+    ],
+    cpuRate: 4,
+  })
+  await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toHaveCount(0)
+  const regions = defineVisualRegions({
+    first: { selector: `[data-timeline-part-id="${firstID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+    last: { selector: `[data-timeline-part-id="${lastID}"]`, closest: '[data-timeline-row="AssistantPart"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    partUpdated(toolPart(questionID, "question", "completed", input, { metadata: { answers: [["Yes"]] } })),
+    600,
+  )
+  await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toBeVisible()
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(testInfo, "question-insert", trace, stablePairPlan(regions, 0))
+})
+
+test("replaces thinking with an assistant error without a blank turn", async ({ page }, testInfo) => {
+  const assistant = assistantMessage([], { completed: false })
+  const timeline = await setupTimeline(page, { messages: [userMessage(), assistant], cpuRate: 4 })
+  await timeline.send(status("busy"), 150)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+  const regions = defineVisualRegions({
+    thinking: { selector: '[data-timeline-row="Thinking"]' },
+    error: { selector: '[data-timeline-row="Error"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    messageUpdated({
+      ...assistant.info,
+      error: { name: "APIError", data: { message: "Provider failed visibly", isRetryable: false } },
+    }),
+    500,
+  )
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await expect(page.locator('[data-timeline-row="Error"]')).toContainText("Provider failed visibly")
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "thinking-error",
+    trace,
+    visualPlan(regions, [
+      { type: "required", regions: ["thinking", "error"] },
+      { type: "continuous-any", regions: ["thinking", "error"] },
+      { type: "unique", regions: ["thinking", "error"] },
+      { type: "opacity", regions: "all" },
+      { type: "continuity", regions: "all" },
+      { type: "motion", regions: "all" },
+      { type: "label-stability", regions: "all" },
+    ]),
+  )
+})
+
+test("updates retry attempts and long provider messages without remounting the retry row", async ({
+  page,
+}, testInfo) => {
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([], { completed: false })],
+    cpuRate: 4,
+  })
+  await timeline.send(status("retry", 1), 120)
+  await expect(page.locator('[data-timeline-row="Retry"]')).toBeVisible()
+  const regions = defineVisualRegions({
+    retry: { selector: '[data-timeline-row="Retry"]' },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    event("session.status", {
+      sessionID: "ses_timeline_stability",
+      status: {
+        type: "retry",
+        attempt: 2,
+        message: "A very long provider retry message ".repeat(8),
+        next: Date.now() + 10_000,
+      },
+    }),
+    300,
+  )
+  await timeline.send(status("retry", 3), 300)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "retry-evolution",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["retry"] },
+        { type: "unique", regions: ["retry"] },
+        { type: "stable", regions: ["retry"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+test("reducer-hardening: removes a historical turn one message at a time without moving a visible lower anchor twice", async ({
+  page,
+}, testInfo) => {
+  const removeUserID = "msg_0500_remove_user"
+  const removeAssistantID = "msg_0501_remove_assistant"
+  const anchorUserID = "msg_2000_anchor_user"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(undefined, { id: removeUserID, created: 1690000000000 }),
+      assistantMessage([textPart("prt_remove_text", "Removed historical content. ".repeat(15))], {
+        id: removeAssistantID,
+        parentID: removeUserID,
+        created: 1690000001000,
+      }),
+      userMessage(undefined, { id: anchorUserID, created: 1700000000000 }),
+      assistantMessage([textPart("prt_anchor_text", "Visible anchor response")], {
+        id: "msg_2001_anchor_assistant",
+        parentID: anchorUserID,
+        created: 1700000001000,
+      }),
+    ],
+    cpuRate: 4,
+  })
+  const regions = defineVisualRegions({
+    anchor: { selector: `[data-timeline-row="UserMessage"][data-message-id="${anchorUserID}"]` },
+  })
+  await startVisualProbe(page, regions)
+  await timeline.send(
+    event("message.removed", { sessionID: "ses_timeline_stability", messageID: removeAssistantID }),
+    200,
+  )
+  await timeline.send(event("message.removed", { sessionID: "ses_timeline_stability", messageID: removeUserID }), 500)
+  const trace = await stopVisualProbe<keyof typeof regions>(page)
+  await reportVisualStability(
+    testInfo,
+    "historical-turn-remove",
+    trace,
+    visualPlan(
+      regions,
+      [
+        { type: "required", regions: ["anchor"] },
+        { type: "unique", regions: ["anchor"] },
+        { type: "stable", regions: ["anchor"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all", maxPositionReversals: 0 },
+        { type: "label-stability", regions: "all" },
+      ],
+      { perMarker: true },
+    ),
+  )
+})
+
+function stablePairPlan(
+  regions: Record<"first" | "last", { selector: string; closest?: string }>,
+  maxPositionReversals: number,
+) {
+  return visualPlan(regions, [
+    { type: "required", regions: ["first", "last"] },
+    { type: "unique", regions: ["first", "last"] },
+    { type: "stable", regions: ["first", "last"] },
+    { type: "opacity", regions: "all" },
+    { type: "continuity", regions: "all" },
+    { type: "motion", regions: "all", maxPositionReversals },
+    { type: "label-stability", regions: "all" },
+  ])
+}

packages/app/e2e/performance/timeline/review-pane-scaling-benchmark.spec.ts

@@ -0,0 +1,312 @@
+import type { Page } from "@playwright/test"
+import { benchmark, expect } from "../benchmark"
+import { setupTimelineBenchmark } from "./session-timeline-benchmark.fixture"
+
+const changedLinesPerFile = 100
+const linesPerSide = changedLinesPerFile / 2
+const fileCounts = [1, 10, 100, 1_000, 10_000]
+const filesPerDirectory = 100
+const readyFrames = 3
+const completionTimeoutMs = Number(process.env.REVIEW_PANE_COMPLETION_TIMEOUT_MS ?? 900_000)
+
+type ReviewPaneScalingSample = {
+  observedAtMs: number
+  logicalRows: number
+  treeRows: number
+  fileRows: number
+  diffLines: number
+  header: string
+  ready: boolean
+}
+
+type ReviewPaneScalingProbe = {
+  startedAt?: number
+  firstTreeRowMs?: number
+  logicalTreeReadyMs?: number
+  firstDiffRenderMs?: number
+  stableReadyMs?: number
+  samples: ReviewPaneScalingSample[]
+  frameTimesMs: number[]
+  longTasks: { startTime: number; duration: number }[]
+  stop: () => void
+}
+
+benchmark.describe("performance: review pane scaling", () => {
+  for (const fileCount of fileCounts) {
+    const changedLines = fileCount * changedLinesPerFile
+
+    benchmark(
+      `${changedLines} changed lines across ${fileCount} ${fileCount === 1 ? "file" : "files"}`,
+      async ({ page, report }) => {
+        benchmark.setTimeout(1_200_000)
+        await page.emulateMedia({ reducedMotion: "reduce" })
+
+        const patchByteLimit = Number(process.env.REVIEW_PANE_PATCH_BYTE_LIMIT ?? Number.POSITIVE_INFINITY)
+        if (Number.isNaN(patchByteLimit) || patchByteLimit < 0)
+          throw new Error(`Invalid REVIEW_PANE_PATCH_BYTE_LIMIT: ${process.env.REVIEW_PANE_PATCH_BYTE_LIMIT}`)
+        const responseBody = JSON.stringify(createScalingDiffs(fileCount, patchByteLimit))
+        await setupTimelineBenchmark(page, {
+          historyTurns: 0,
+          eventBatch: 1,
+          newLayoutDesigns: true,
+        })
+        await page.route("**/vcs/diff**", (route) =>
+          route.fulfill({
+            status: 200,
+            contentType: "application/json",
+            headers: { "access-control-allow-origin": "*" },
+            body: responseBody,
+          }),
+        )
+
+        const expectedRows = fileCount + 2 + Math.ceil(fileCount / filesPerDirectory)
+        const metrics = await measureReviewPaneLoad(page, {
+          expectedFile: reviewFile(0),
+          expectedRows,
+        })
+        const search = await measureBroadReviewSearch(page, fileCount)
+
+        expect(metrics.logicalRows).toBe(expectedRows)
+        expect(metrics.fileRows).toBeGreaterThan(0)
+        expect(metrics.treeRows).toBeGreaterThan(0)
+        expect(metrics.diffLines).toBeGreaterThan(0)
+        expect(search.logicalRows).toBe(fileCount)
+        expect(search.renderedRows).toBeGreaterThan(0)
+        report(
+          { ...metrics, search },
+          {
+            fileCount,
+            changedLinesPerFile,
+            changedLines,
+            additions: changedLines / 2,
+            deletions: changedLines / 2,
+            patchLines: changedLines,
+            patchByteLimit: Number.isFinite(patchByteLimit) ? patchByteLimit : null,
+            payloadBytes: new TextEncoder().encode(responseBody).byteLength,
+            expectedRows,
+          },
+        )
+      },
+    )
+  }
+})
+
+async function measureBroadReviewSearch(page: Page, expectedRows: number) {
+  const filter = page.getByRole("searchbox", { name: "Filter files" })
+  await filter.evaluate((element) => {
+    element.addEventListener(
+      "input",
+      () => {
+        ;(window as Window & { __reviewSearchStartedAt?: number }).__reviewSearchStartedAt = performance.now()
+      },
+      { once: true, capture: true },
+    )
+  })
+  await filter.fill("file-")
+
+  return page.evaluate((expectedRows) => {
+    const startedAt = (window as Window & { __reviewSearchStartedAt?: number }).__reviewSearchStartedAt!
+    return new Promise<{ stableMs: number; logicalRows: number; renderedRows: number }>((resolve) => {
+      let previous = -1
+      let streak = 0
+      const sample = () => {
+        const tree = document.querySelector<HTMLElement>('#review-panel [data-component="file-tree-v2"]')
+        const rows = [...document.querySelectorAll<HTMLElement>('#review-panel [data-slot="file-tree-v2-row"]')]
+        const logicalRows = Number(tree?.dataset.totalRows ?? rows.length)
+        const ready =
+          logicalRows === expectedRows && rows.length > 0 && rows.every((row) => row.textContent?.includes("file-"))
+        streak = ready && rows.length === previous ? streak + 1 : ready ? 1 : 0
+        previous = rows.length
+        if (streak >= 3) {
+          resolve({ stableMs: performance.now() - startedAt, logicalRows, renderedRows: rows.length })
+          return
+        }
+        requestAnimationFrame(sample)
+      }
+      requestAnimationFrame(sample)
+    })
+  }, expectedRows)
+}
+
+function createScalingDiffs(fileCount: number, patchByteLimit: number) {
+  const changes = Array.from({ length: linesPerSide }, (_, index) => {
+    const line = String(index).padStart(3, "0")
+    return `-export const value_${line} = "before"\n+export const value_${line} = "after"`
+  }).join("\n")
+  let patchBytes = 0
+  let capped = false
+
+  return Array.from({ length: fileCount }, (_, index) => {
+    const file = reviewFile(index)
+    const fullPatch = [
+      `diff --git a/${file} b/${file}`,
+      `--- a/${file}`,
+      `+++ b/${file}`,
+      `@@ -1,${linesPerSide} +1,${linesPerSide} @@`,
+      changes,
+    ].join("\n")
+    if (index === 0 && fullPatch.length > patchByteLimit)
+      throw new Error(`REVIEW_PANE_PATCH_BYTE_LIMIT must include the active patch (${fullPatch.length} bytes)`)
+    const patch = !capped && patchBytes + fullPatch.length <= patchByteLimit ? fullPatch : emptyReviewPatch(file)
+    if (patch === fullPatch) patchBytes += fullPatch.length
+    else capped = true
+    return {
+      file,
+      patch,
+      additions: linesPerSide,
+      deletions: linesPerSide,
+      status: "modified" as const,
+    }
+  })
+}
+
+function emptyReviewPatch(file: string) {
+  return [`diff --git a/${file} b/${file}`, `--- a/${file}`, `+++ b/${file}`].join("\n")
+}
+
+function reviewFile(index: number) {
+  return `src/review/d${String(Math.floor(index / filesPerDirectory)).padStart(5, "0")}/file-${String(index).padStart(5, "0")}.ts`
+}
+
+async function measureReviewPaneLoad(page: Page, input: { expectedFile: string; expectedRows: number }) {
+  const toggle = page.getByRole("button", { name: "Toggle review" })
+  await expect(toggle).toBeVisible()
+  await toggle.evaluate((element) => element.setAttribute("data-review-pane-scaling-toggle", ""))
+  await installReviewPaneScalingProbe(page, input)
+  await toggle.click()
+  await page.waitForFunction(
+    () =>
+      (window as Window & { __reviewPaneScalingProbe?: ReviewPaneScalingProbe }).__reviewPaneScalingProbe
+        ?.stableReadyMs !== undefined,
+    undefined,
+    { timeout: completionTimeoutMs },
+  )
+
+  return page.evaluate(() => {
+    const probe = (window as Window & { __reviewPaneScalingProbe?: ReviewPaneScalingProbe }).__reviewPaneScalingProbe!
+    probe.stop()
+    const startedAt = probe.startedAt!
+    const final = probe.samples.at(-1)!
+    const resources = performance
+      .getEntriesByType("resource")
+      .filter((entry) => entry.name.includes("/vcs/diff")) as PerformanceResourceTiming[]
+    const resource = resources.at(-1)
+    const longTasks = probe.longTasks.filter(
+      (entry) => entry.startTime >= startedAt && entry.startTime <= startedAt + probe.stableReadyMs!,
+    )
+    const frameGaps = probe.frameTimesMs.map((time, index) => time - (probe.frameTimesMs[index - 1] ?? 0))
+
+    return {
+      firstTreeRowMs: probe.firstTreeRowMs ?? null,
+      logicalTreeReadyMs: probe.logicalTreeReadyMs ?? null,
+      firstDiffRenderMs: probe.firstDiffRenderMs ?? null,
+      stableReadyMs: probe.stableReadyMs ?? null,
+      responseStartMs: resource ? resource.responseStart - startedAt : null,
+      responseEndMs: resource ? resource.responseEnd - startedAt : null,
+      responseToStableMs: resource ? probe.stableReadyMs! - (resource.responseEnd - startedAt) : null,
+      treeRows: final.treeRows,
+      logicalRows: final.logicalRows,
+      fileRows: final.fileRows,
+      diffLines: final.diffLines,
+      samples: probe.samples.length,
+      maxFrameGapMs: Math.max(0, ...frameGaps),
+      longTaskCount: longTasks.length,
+      longTaskTotalMs: longTasks.reduce((sum, entry) => sum + entry.duration, 0),
+      maxLongTaskMs: Math.max(0, ...longTasks.map((entry) => entry.duration)),
+    }
+  })
+}
+
+async function installReviewPaneScalingProbe(page: Page, input: { expectedFile: string; expectedRows: number }) {
+  await page.evaluate(
+    ({ expectedFile, expectedRows, stableFrames }) => {
+      let running = true
+      let readyStreak = 0
+      const basename = expectedFile.split("/").at(-1)!
+      const longTaskObserver = PerformanceObserver.supportedEntryTypes.includes("longtask")
+        ? new PerformanceObserver((list) => {
+            probe.longTasks.push(
+              ...list.getEntries().map((entry) => ({ startTime: entry.startTime, duration: entry.duration })),
+            )
+          })
+        : undefined
+      const probe: ReviewPaneScalingProbe = {
+        samples: [],
+        frameTimesMs: [],
+        longTasks: [],
+        stop: () => {
+          running = false
+          longTaskObserver?.disconnect()
+        },
+      }
+
+      const sample = (time: number) => {
+        if (!running || probe.startedAt === undefined) return
+        const panel = document.querySelector<HTMLElement>("#review-panel")
+        const tree = panel?.querySelector<HTMLElement>('[data-component="file-tree-v2"]')
+        const rows = panel?.querySelectorAll('[data-slot="file-tree-v2-row"]') ?? []
+        const fileRows = panel?.querySelectorAll('button[data-slot="file-tree-v2-row"]') ?? []
+        const header =
+          panel?.querySelector<HTMLElement>('[data-slot="session-review-v2-file-header"]')?.textContent?.trim() ?? ""
+        const viewers = panel
+          ? [...panel.querySelectorAll<HTMLElement>('[data-component="file"][data-mode="diff"]')]
+          : []
+        const diffLines = viewers.reduce(
+          (sum, viewer) =>
+            sum + (viewer.querySelector("diffs-container")?.shadowRoot?.querySelectorAll("[data-line]").length ?? 0),
+          0,
+        )
+        const observedAtMs = time - probe.startedAt
+        const logicalRows = Number(tree?.dataset.totalRows ?? rows.length)
+        const ready =
+          logicalRows === expectedRows &&
+          fileRows.length > 0 &&
+          header.includes(basename) &&
+          viewers.length === 1 &&
+          diffLines > 0
+        const previous = probe.samples.at(-1)
+        const stable =
+          ready &&
+          previous?.ready === true &&
+          previous.logicalRows === logicalRows &&
+          previous.treeRows === rows.length &&
+          previous.fileRows === fileRows.length &&
+          previous.diffLines === diffLines &&
+          previous.header === header
+
+        probe.frameTimesMs.push(observedAtMs)
+        probe.samples.push({
+          observedAtMs,
+          logicalRows,
+          treeRows: rows.length,
+          fileRows: fileRows.length,
+          diffLines,
+          header,
+          ready,
+        })
+        if (probe.firstTreeRowMs === undefined && rows.length > 0) probe.firstTreeRowMs = observedAtMs
+        if (probe.logicalTreeReadyMs === undefined && logicalRows === expectedRows)
+          probe.logicalTreeReadyMs = observedAtMs
+        if (probe.firstDiffRenderMs === undefined && diffLines > 0) probe.firstDiffRenderMs = observedAtMs
+        readyStreak = !ready ? 0 : stable ? readyStreak + 1 : 1
+        if (readyStreak === stableFrames) probe.stableReadyMs = observedAtMs
+        if (probe.stableReadyMs === undefined) requestAnimationFrame(sample)
+      }
+
+      longTaskObserver?.observe({ type: "longtask", buffered: true })
+      document.addEventListener(
+        "click",
+        (event) => {
+          const toggle = event.target instanceof Element ? event.target.closest("button") : undefined
+          if (!toggle?.hasAttribute("data-review-pane-scaling-toggle")) return
+          probe.startedAt = performance.now()
+          performance.mark("opencode.review-pane-scaling.click")
+          requestAnimationFrame(sample)
+        },
+        { capture: true, once: true },
+      )
+      ;(window as Window & { __reviewPaneScalingProbe?: ReviewPaneScalingProbe }).__reviewPaneScalingProbe = probe
+    },
+    { ...input, stableFrames: readyFrames },
+  )
+}

packages/app/e2e/performance/timeline/session-parent-hydration-benchmark.spec.ts

@@ -0,0 +1,151 @@
+import type { Page } from "@playwright/test"
+import { expectSessionTitle } from "../../utils/waits"
+import { mockOpenCodeServer } from "../../utils/mock-server"
+import { benchmark, expect, withBenchmarkPage } from "../benchmark"
+import { fixture } from "./session-timeline-stress.fixture"
+import { installStressSessionTabs, stressSessionHref } from "./timeline-test-helpers"
+import { measureSessionSwitch, waitForStableTimeline } from "./session-tab-switch-probe"
+
+type ParentHydrationBenchmarkMode = "natural" | "candidate"
+
+const mode = process.env.SESSION_PARENT_HYDRATION_BENCHMARK_MODE ?? "natural"
+if (mode !== "natural" && mode !== "candidate") throw new Error(`Unknown parent hydration benchmark mode: ${mode}`)
+const userID = "msg_parent_hydration_user"
+const user = {
+  ...fixture.messages[fixture.targetID][0]!,
+  info: { ...fixture.messages[fixture.targetID][0]!.info, id: userID, time: { created: 1700001000000 } },
+  parts: fixture.messages[fixture.targetID][0]!.parts.map((part, index) => ({
+    ...part,
+    id: `prt_parent_hydration_user_${index}`,
+    messageID: userID,
+  })),
+}
+const assistantSeed = fixture.messages[fixture.targetID][3]!
+const assistants = Array.from({ length: 14 }, (_, index) => {
+  const messageID = `msg_parent_hydration_${String(index).padStart(2, "0")}`
+  return {
+    ...assistantSeed,
+    info: {
+      ...assistantSeed.info,
+      id: messageID,
+      parentID: userID,
+      time: { created: 1700001001000 + index * 1_000, completed: 1700001001500 + index * 1_000 },
+    },
+    parts: assistantSeed.parts.map((part, partIndex) => ({
+      ...part,
+      id: `prt_parent_hydration_${String(index).padStart(2, "0")}_${partIndex}`,
+      messageID,
+    })),
+  }
+})
+const messages = [user, ...assistants]
+const target = fixture.sessions.find((session) => session.id === fixture.targetID)!
+const lastID = userID
+const lastPartID = assistants.at(-1)!.parts.at(-1)!.id
+
+benchmark("hydrates an orphaned latest turn after a cold session click", async ({ browser, report }, testInfo) => {
+  benchmark.setTimeout(180_000)
+  const results = [] as Awaited<ReturnType<typeof trial>>[]
+  for (let run = 0; run < 5; run++) {
+    results.push(
+      await withBenchmarkPage(
+        browser,
+        `session-parent-hydration-${mode}-${run}`,
+        (page) => trial(page, mode),
+        testInfo,
+      ),
+    )
+  }
+  const timing = results.map((result) => result.metrics.firstCorrectObservedMs!).sort((a, b) => a - b)
+  report(
+    {
+      results: results.map((result) => ({ ...result.metrics, historyGateCount: result.historyGateCount })),
+      summary: {
+        firstCorrectObservedMs: { min: timing[0], median: timing[2], max: timing.at(-1) },
+        blankSamples: results.map((result) => result.metrics.blankSamples),
+        requestCounts: {
+          list: results.map((result) => result.requestCounts.list),
+          parent: results.map((result) => result.requestCounts.parent),
+        },
+        historyGateCount: results.map((result) => result.historyGateCount),
+      },
+    },
+    { mode },
+  )
+})
+
+async function trial(page: Page, mode: ParentHydrationBenchmarkMode) {
+  const requests: { type: "list" | "parent"; before?: string }[] = []
+  const history = mode === "candidate" ? Promise.withResolvers<void>() : undefined
+  let historyGates = 0
+  await mockOpenCodeServer(page, {
+    sessions: fixture.sessions.filter((session) => session.id === fixture.sourceID),
+    provider: fixture.provider,
+    directory: fixture.directory,
+    project: fixture.project,
+    messageDelay: 50,
+    onMessages: (request) => {
+      if (request.sessionID === fixture.targetID && request.phase === "start")
+        requests.push({ type: "list", before: request.before })
+    },
+    beforeMessagesResponse: (request) => {
+      if (mode !== "candidate" || request.sessionID !== fixture.targetID || !request.before) return Promise.resolve()
+      historyGates++
+      return history!.promise
+    },
+    onMessage: (request) => {
+      if (request.sessionID === fixture.targetID && request.messageID === userID) requests.push({ type: "parent" })
+    },
+    message: (sessionID, messageID) => {
+      if (sessionID !== fixture.targetID || messageID !== userID) return
+      return user
+    },
+    pageMessages: (sessionID, limit, before) => {
+      const items = sessionID === fixture.targetID ? messages : fixture.messages[fixture.sourceID]
+      const end = before ? items.findIndex((message) => message.info.id === before) : items.length
+      const start = Math.max(0, end - limit)
+      return { items: items.slice(start, end), cursor: start > 0 ? items[start]!.info.id : undefined }
+    },
+  })
+  await page.route(`**/session/${fixture.targetID}`, (route) =>
+    route.fulfill({ status: 200, contentType: "application/json", body: JSON.stringify(target) }),
+  )
+  await installStressSessionTabs(page, { sessionIDs: [fixture.sourceID] })
+  await page.goto(stressSessionHref(fixture.sourceID))
+  await expectSessionTitle(page, fixture.expected.sourceTitle)
+  await waitForStableTimeline(page, fixture.expected.sourceMessageIDs.at(-1)!)
+
+  const href = stressSessionHref(fixture.targetID)
+  await page.evaluate(
+    ({ href, title }) => {
+      const link = document.createElement("a")
+      link.id = "parent-hydration-target"
+      link.href = href
+      link.textContent = title
+      document.body.append(link)
+    },
+    { href, title: target.title },
+  )
+  const metrics = await measureSessionSwitch(page, {
+    destinationIDs: messages.map((message) => message.info.id),
+    sourceIDs: fixture.messages[fixture.sourceID].map((message) => message.info.id),
+    lastID,
+    requiredPartID: lastPartID,
+    requireBottomAnchor: false,
+    href,
+    switch: async () => {
+      await page.locator("#parent-hydration-target").click()
+      await expectSessionTitle(page, target.title)
+    },
+  }).finally(() => history?.resolve())
+  expect(metrics.firstCorrectObservedMs).not.toBeNull()
+  const requestCounts = {
+    list: requests.filter((request) => request.type === "list").length,
+    parent: requests.filter((request) => request.type === "parent").length,
+  }
+  if (mode === "candidate") {
+    expect(requestCounts.parent).toBe(1)
+    expect(historyGates).toBe(1)
+  }
+  return { metrics, requestCounts, historyGateCount: historyGates }
+}

packages/app/e2e/performance/timeline/session-tab-switch-benchmark.spec.ts

@@ -2,7 +2,13 @@ import type { Page } from "@playwright/test"
 import { expectSessionTitle } from "../../utils/waits"
 import { benchmark, expect, withBenchmarkPage } from "../benchmark"
 import { fixture } from "./session-timeline-stress.fixture"
-import { installStressSessionTabs, mockStressTimeline, stressSessionHref } from "./timeline-test-helpers"
+import {
+  createReviewDiffs,
+  installStressSessionTabs,
+  installTimelineSettings,
+  mockStressTimeline,
+  stressSessionHref,
+} from "./timeline-test-helpers"
 import { measureSessionSwitch, waitForStableTimeline } from "./session-tab-switch-probe"
 
 type Result = Awaited<ReturnType<typeof measureSessionSwitch>>
@@ -20,8 +26,41 @@ benchmark("benchmarks cold and hot session tab switching", async ({ browser, rep
   report({ results, summary: summarize(results) })
 })
 
-async function trial(page: Page, mode: "cold" | "hot") {
-  await mockStressTimeline(page)
+benchmark(
+  "benchmarks v2 session tab switching with and without the review pane",
+  async ({ browser, report }, testInfo) => {
+    benchmark.setTimeout(360_000)
+    const runs = Number(process.env.SESSION_TAB_SWITCH_RUNS ?? 5)
+    const results = {
+      closed: { cold: [] as Result[], hot: [] as Result[] },
+      open: { cold: [] as Result[], hot: [] as Result[] },
+    }
+    for (const reviewPane of ["closed", "open"] as const) {
+      for (const mode of ["cold", "hot"] as const) {
+        for (let run = 0; run < runs; run++) {
+          results[reviewPane][mode].push(
+            await withBenchmarkPage(
+              browser,
+              `session-tab-switch-v2-${reviewPane}-${mode}-${run}`,
+              (page) => trial(page, mode, { newLayoutDesigns: true, reviewPane }),
+              testInfo,
+            ),
+          )
+        }
+      }
+    }
+    report({ results, summary: summarizeReviewPane(results) }, { runs, reviewDiffs: createReviewDiffs().length })
+  },
+)
+
+async function trial(
+  page: Page,
+  mode: "cold" | "hot",
+  options?: { newLayoutDesigns?: boolean; reviewPane?: "closed" | "open" },
+) {
+  const reviewDiffs = options?.newLayoutDesigns ? createReviewDiffs() : undefined
+  await mockStressTimeline(page, { vcsDiff: reviewDiffs })
+  if (options?.newLayoutDesigns) await installTimelineSettings(page)
   await installStressSessionTabs(page)
   if (mode === "hot") {
     await page.goto(stressSessionHref(fixture.targetID))
@@ -33,6 +72,10 @@ async function trial(page: Page, mode: "cold" | "hot") {
     await expectSessionTitle(page, fixture.expected.sourceTitle)
   }
   await waitForStableTimeline(page, fixture.expected.sourceMessageIDs.at(-1)!)
+  if (options?.reviewPane === "open") {
+    await openReviewPane(page)
+    await waitForStableTimeline(page, fixture.expected.sourceMessageIDs.at(-1)!)
+  }
 
   const destinationIDs = fixture.messages[fixture.targetID].map((message) => message.info.id)
   const sourceIDs = fixture.messages[fixture.sourceID].map((message) => message.info.id)
@@ -70,6 +113,15 @@ function summarize(results: Record<"cold" | "hot", Result[]>) {
   )
 }
 
+function summarizeReviewPane(results: Record<"closed" | "open", Record<"cold" | "hot", Result[]>>) {
+  return Object.fromEntries(
+    Object.entries(results).map(([reviewPane, values]) => [
+      reviewPane,
+      summarize(values as Record<"cold" | "hot", Result[]>),
+    ]),
+  )
+}
+
 async function switchSession(page: Page, sessionID: string, title: string) {
   const href = stressSessionHref(sessionID)
   const tab = page.locator(`[data-slot="titlebar-tabs"] a[href="${href}"]`).first()
@@ -77,3 +129,16 @@ async function switchSession(page: Page, sessionID: string, title: string) {
   await tab.click()
   await expectSessionTitle(page, title)
 }
+
+async function openReviewPane(page: Page) {
+  await page.getByRole("button", { name: "Toggle review" }).click()
+  const panel = page.locator("#review-panel")
+  await expect(panel).toBeVisible()
+  // Text-based readiness works across review implementations; the legacy list mounts
+  // diff viewers lazily while V2 mounts the active preview eagerly.
+  await page.waitForFunction(() => {
+    const panel = document.querySelector<HTMLElement>("#review-panel")
+    const text = panel?.textContent ?? ""
+    return text.includes("generated-000.ts") && text.includes("+3")
+  })
+}

packages/app/e2e/performance/timeline/session-tab-switch-metrics.ts

@@ -4,7 +4,15 @@ export type SessionSwitchSample = {
   source: string[]
   hasVisibleRows: boolean
   last: boolean
+  requiredPartVisible?: boolean
+  bottomAnchorRequired?: boolean
   bottomErrorPx?: number
+  review?: {
+    fileHost: boolean
+    fileHostReplaced: boolean
+    header: string
+    replacedLevels: string[]
+  }
 }
 
 export function classifySessionSwitch(samples: SessionSwitchSample[]) {
@@ -23,6 +31,10 @@ export function classifySessionSwitch(samples: SessionSwitchSample[]) {
       (sample) => sample.hasVisibleRows && sample.destination.length === 0 && sample.source.length === 0,
     ).length,
     sourceSamples: samples.filter((sample) => sample.source.length > 0).length,
+    reviewFileHostMissingSamples: samples.filter((sample) => sample.review && !sample.review.fileHost).length,
+    reviewFileHostReplacedSamples: samples.filter((sample) => sample.review?.fileHostReplaced).length,
+    reviewHeaders: [...new Set(samples.flatMap((sample) => (sample.review ? [sample.review.header] : [])))],
+    reviewReplacedLevels: [...new Set(samples.flatMap((sample) => sample.review?.replacedLevels ?? []))],
   }
 }
 
@@ -31,7 +43,8 @@ export function isCorrectDestination(sample: SessionSwitchSample) {
     sample.destination.length > 0 &&
     sample.source.length === 0 &&
     sample.last &&
-    Math.abs(sample.bottomErrorPx ?? Infinity) <= 1
+    sample.requiredPartVisible !== false &&
+    (sample.bottomAnchorRequired === false || Math.abs(sample.bottomErrorPx ?? Infinity) <= 1)
   )
 }
 

packages/app/e2e/performance/timeline/session-tab-switch-probe.ts

@@ -8,19 +8,56 @@ type SessionSwitchProbe = {
 
 async function installSessionSwitchProbe(
   page: Page,
-  input: { destinationIDs: string[]; sourceIDs: string[]; lastID: string; href: string },
+  input: {
+    destinationIDs: string[]
+    sourceIDs: string[]
+    lastID: string
+    requiredPartID?: string
+    requireBottomAnchor?: boolean
+    href: string
+  },
 ) {
-  await page.evaluate(({ destinationIDs, sourceIDs, lastID, href }) => {
+  await page.evaluate(({ destinationIDs, sourceIDs, lastID, requiredPartID, requireBottomAnchor, href }) => {
     const destination = new Set(destinationIDs)
     const source = new Set(sourceIDs)
     const samples: SessionSwitchSample[] = []
     let started: number | undefined
     let running = true
+    const reviewLevels: Record<string, string> = {
+      panel: "#review-panel",
+      tabs: '#review-panel [data-component="tabs"]',
+      body: '#review-panel [data-slot="session-review-v2-body"]',
+      review: '#review-panel [data-component="session-review-v2"]',
+      preview: '#review-panel [data-slot="session-review-v2-preview"]',
+      scroll: '#review-panel [data-slot="session-review-v2-diff-scroll"]',
+      file: '#review-panel [data-component="file"][data-mode="diff"]',
+    }
+    const initialReviewNodes: Record<string, Element | null> = {}
     const sample = () => {
       if (!running || started === undefined) return
       setTimeout(() => {
         if (!running || started === undefined) return
         const observedAtMs = performance.now() - started
+        const reviewPanel = document.querySelector<HTMLElement>("#review-panel")
+        const reviewFile = reviewPanel?.querySelector('[data-component="file"][data-mode="diff"]')
+        const initialReviewFile = initialReviewNodes.file
+        const replacedLevels = Object.entries(reviewLevels).flatMap(([name, selector]) => {
+          const initial = initialReviewNodes[name]
+          if (!initial) return []
+          const current = document.querySelector(selector)
+          return current && current !== initial ? [name] : []
+        })
+        const review = reviewPanel
+          ? {
+              fileHost: !!reviewFile,
+              fileHostReplaced: !!initialReviewFile && !!reviewFile && reviewFile !== initialReviewFile,
+              header:
+                reviewPanel
+                  .querySelector<HTMLElement>('[data-slot="session-review-v2-file-header"]')
+                  ?.textContent?.trim() ?? "",
+              replacedLevels,
+            }
+          : undefined
         const root = [...document.querySelectorAll<HTMLElement>(".scroll-view__viewport")].find((element) =>
           element.querySelector("[data-timeline-row]"),
         )
@@ -36,6 +73,13 @@ async function installSessionSwitchProbe(
             const rect = element.getBoundingClientRect()
             return rect.bottom > view.top && rect.top < view.bottom
           })
+          const requiredPartVisible = requiredPartID
+            ? [...root.querySelectorAll<HTMLElement>("[data-timeline-part-id]")].some((element) => {
+                if (element.dataset.timelinePartId !== requiredPartID) return false
+                const rect = element.getBoundingClientRect()
+                return rect.width > 0 && rect.height > 0 && rect.bottom > view.top && rect.top < view.bottom
+              })
+            : undefined
           const spacer = root.querySelector<HTMLElement>('[data-timeline-row="bottom-spacer"]')?.getBoundingClientRect()
           samples.push({
             observedAtMs,
@@ -43,10 +87,22 @@ async function installSessionSwitchProbe(
             source: visible.filter((id) => source.has(id)),
             hasVisibleRows,
             last: visible.includes(lastID),
+            requiredPartVisible,
+            bottomAnchorRequired: requireBottomAnchor !== false,
             bottomErrorPx: spacer ? spacer.bottom - view.bottom : undefined,
+            review,
           })
         } else {
-          samples.push({ observedAtMs, destination: [], source: [], hasVisibleRows: false, last: false })
+          samples.push({
+            observedAtMs,
+            destination: [],
+            source: [],
+            hasVisibleRows: false,
+            last: false,
+            requiredPartVisible: requiredPartID ? false : undefined,
+            bottomAnchorRequired: requireBottomAnchor !== false,
+            review,
+          })
         }
         requestAnimationFrame(sample)
       }, 0)
@@ -57,6 +113,9 @@ async function installSessionSwitchProbe(
         const link = event.target instanceof Element ? event.target.closest("a") : undefined
         if (link?.getAttribute("href") !== href) return
         started = performance.now()
+        for (const [name, selector] of Object.entries(reviewLevels)) {
+          initialReviewNodes[name] = document.querySelector(selector)
+        }
         requestAnimationFrame(sample)
       },
       { capture: true, once: true },
@@ -83,7 +142,8 @@ async function waitForStableSessionSwitch(page: Page) {
             sample.destination.length > 0 &&
             sample.source.length === 0 &&
             sample.last &&
-            Math.abs(sample.bottomErrorPx ?? Infinity) <= 1,
+            sample.requiredPartVisible !== false &&
+            (sample.bottomAnchorRequired === false || Math.abs(sample.bottomErrorPx ?? Infinity) <= 1),
         )
       )
     })
@@ -101,13 +161,27 @@ async function collectSessionSwitchResult(page: Page) {
 
 export async function measureSessionSwitch(
   page: Page,
-  input: { destinationIDs: string[]; sourceIDs: string[]; lastID: string; href: string; switch: () => Promise<void> },
+  input: {
+    destinationIDs: string[]
+    sourceIDs: string[]
+    lastID: string
+    requiredPartID?: string
+    requireBottomAnchor?: boolean
+    href: string
+    switch: () => Promise<void>
+  },
 ) {
   const { switch: run, ...probe } = input
   await installSessionSwitchProbe(page, probe)
-  await run()
-  await waitForStableSessionSwitch(page)
-  return collectSessionSwitchResult(page)
+  try {
+    await run()
+    await waitForStableSessionSwitch(page)
+    return await collectSessionSwitchResult(page)
+  } finally {
+    await page.evaluate(() => {
+      ;(window as Window & { __sessionSwitchProbe?: SessionSwitchProbe }).__sessionSwitchProbe?.stop()
+    })
+  }
 }
 
 export async function waitForStableTimeline(page: Page, lastID: string) {

packages/app/e2e/performance/timeline/session-timeline-benchmark.fixture.ts

@@ -93,36 +93,53 @@ const assistantMessage = {
   parts: [editPart],
 }
 
-export async function setupTimelineBenchmark(page: Page, options: { historyTurns: number; eventBatch: number }) {
+export async function setupTimelineBenchmark(
+  page: Page,
+  options: {
+    historyTurns: number
+    eventBatch: number
+    newLayoutDesigns?: boolean
+    vcsDiff?: unknown[]
+    turnDiffs?: unknown[]
+  },
+) {
   const events: EventPayload[] = []
   let eventBatch = options.eventBatch
+  const currentUserMessage = options.turnDiffs
+    ? { ...userMessage, info: { ...userMessage.info, summary: { diffs: options.turnDiffs } } }
+    : userMessage
   await mockOpenCodeServer(page, {
     directory,
     project: project(),
     provider: provider(),
     sessions: [session()],
+    vcsDiff: options.vcsDiff,
     pageMessages: () => ({
       items: [
         ...Array.from({ length: options.historyTurns }, (_, index) => performanceTurn(index)).flat(),
-        userMessage,
+        currentUserMessage,
         assistantMessage,
       ],
     }),
     events: () => events.splice(0, eventBatch),
     eventRetry: 16,
   })
-  await page.addInitScript(() => {
-    localStorage.setItem(
-      "settings.v3",
-      JSON.stringify({
-        general: {
-          editToolPartsExpanded: true,
-          shellToolPartsExpanded: true,
-          showReasoningSummaries: true,
-        },
-      }),
-    )
-  })
+  await page.addInitScript(
+    (input) => {
+      localStorage.setItem(
+        "settings.v3",
+        JSON.stringify({
+          general: {
+            newLayoutDesigns: input.newLayoutDesigns,
+            editToolPartsExpanded: true,
+            shellToolPartsExpanded: true,
+            showReasoningSummaries: true,
+          },
+        }),
+      )
+    },
+    { newLayoutDesigns: options.newLayoutDesigns ?? false },
+  )
   await page.setViewportSize({ width: 1366, height: 768 })
   const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
   const text = page.locator(`[data-timeline-part-id="${textPartID}"]`).first()

packages/app/e2e/performance/timeline/session-timeline-benchmark.spec.ts

@@ -1,3 +1,4 @@
+import type { Page } from "@playwright/test"
 import { benchmark, benchmarkDiagnostics, expect } from "../benchmark"
 import {
   buildInitialStreamEvent,
@@ -6,80 +7,300 @@ import {
   textPartID,
 } from "./session-timeline-benchmark.fixture"
 import { startTimelineProfile } from "./session-timeline-profile"
+import { createReviewDiffs } from "./timeline-test-helpers"
 import {
   collectTimelineStreamMetrics,
   installTimelineStreamProbe,
   startTimelineStreamProbe,
 } from "./session-timeline-stream-probe"
 
+type TimelineStreamOptions = {
+  newLayoutDesigns?: boolean
+  reviewDiffs?: boolean
+  reviewPane?: boolean
+}
+
+type ReviewPaneSample = {
+  observedAtMs: number
+  panelVisible: boolean
+  header: string
+  diffViewers: number
+  diffLines: number
+  codeBlocks: number
+  ready: boolean
+}
+
+type ReviewPaneProbe = {
+  samples: ReviewPaneSample[]
+  start: () => void
+  stop: () => void
+}
+
+const reviewReadyStreak = 3
+
 benchmark.describe("performance: session timeline streaming", () => {
   benchmark("streams assistant text without remounting or oscillating", async ({ page, report }) => {
-    benchmark.setTimeout(480_000)
-    const cpuThrottle = Number(process.env.TIMELINE_CPU_THROTTLE ?? 30)
-    const deltaCount = Number(process.env.TIMELINE_DELTA_COUNT ?? 160)
-    const historyTurns = Number(process.env.TIMELINE_HISTORY_TURNS ?? 320)
-    const eventBatch = Number(process.env.TIMELINE_EVENT_BATCH ?? 1)
-    const minimal = process.env.TIMELINE_MINIMAL === "1"
-    const profileCPU = process.env.TIMELINE_CPU_PROFILE === "1"
-    const profileVisual = !minimal && profileCPU && process.env.TIMELINE_VISUAL_PROFILE !== "0"
+    benchmark.setTimeout(Number(process.env.TIMELINE_COMPLETION_TIMEOUT_MS ?? 420_000) + 60_000)
+    const result = await runTimelineStreamBenchmark(page, {})
+    report(result.metrics, result.context)
+  })
+
+  benchmark("streams assistant text in v2 with review pane closed", async ({ page, report }) => {
+    benchmark.setTimeout(Number(process.env.TIMELINE_COMPLETION_TIMEOUT_MS ?? 420_000) + 60_000)
+    const result = await runTimelineStreamBenchmark(page, { newLayoutDesigns: true })
+    report(result.metrics, result.context)
+  })
+
+  benchmark("streams assistant text in v2 with review diffs and pane closed", async ({ page, report }) => {
+    benchmark.setTimeout(Number(process.env.TIMELINE_COMPLETION_TIMEOUT_MS ?? 420_000) + 60_000)
+    const result = await runTimelineStreamBenchmark(page, { newLayoutDesigns: true, reviewDiffs: true })
+    report(result.metrics, result.context)
+  })
+
+  benchmark("streams assistant text in v2 with review pane open", async ({ page, report }) => {
+    benchmark.setTimeout(Number(process.env.TIMELINE_COMPLETION_TIMEOUT_MS ?? 420_000) + 60_000)
+    const result = await runTimelineStreamBenchmark(page, { newLayoutDesigns: true, reviewPane: true })
+    report(result.metrics, result.context)
+  })
+})
+
+benchmark.describe("performance: review pane", () => {
+  benchmark("loads v2 review diffs and switches active files", async ({ page, report }) => {
+    benchmark.setTimeout(240_000)
+    const historyTurns = Number(process.env.REVIEW_PANE_HISTORY_TURNS ?? 72)
+    const diffs = createReviewDiffs()
     const fixture = await setupTimelineBenchmark(page, {
       historyTurns,
-      eventBatch,
+      eventBatch: 1,
+      newLayoutDesigns: true,
+      vcsDiff: diffs,
     })
 
-    fixture.transport.enqueue(buildInitialStreamEvent(deltaCount))
-    const contentStart = performance.now()
+    fixture.transport.enqueue(buildInitialStreamEvent(1))
     await expect(fixture.text).toBeVisible()
     await expect(fixture.text).toContainText("Implementation plan")
-    const initialContentObservedMs = performance.now() - contentStart
     await fixture.scrollToBottom()
     await fixture.waitForStableGeometry()
 
-    const profile = await startTimelineProfile(page, { cpuThrottle, profileCPU })
-    await installTimelineStreamProbe(page, { textPartID, finalIndex: deltaCount, profileVisual, minimal })
-    const deltas = buildStreamDeltaEvents(deltaCount)
-    await startTimelineStreamProbe(page)
-    fixture.transport.enqueue(deltas)
-
-    await page.waitForFunction(
-      (finalIndex) =>
-        (
-          window as Window & {
-            __timelineStreamBenchmark?: { applied: { index: number }[] }
-          }
-        ).__timelineStreamBenchmark?.applied.some((value) => value.index === finalIndex),
-      deltaCount,
-      { timeout: 420_000 },
-    )
-    await expect(fixture.text).toContainText("benchmark-complete")
-    await expect(fixture.text).toContainText("Streaming")
-    await fixture.waitForStableGeometry()
-    const metrics = await collectTimelineStreamMetrics(page, {
-      textPartID,
-      finalIndex: deltaCount,
-      navigations: benchmarkDiagnostics(page).navigations,
-    })
-    const delivered = deltas.length - fixture.transport.pendingCount()
-    await profile.stop()
+    const open = await measureReviewPaneLoad(page, diffs[0]!.file)
+    const switches = []
+    for (const diff of diffs.slice(1, 4)) switches.push(await measureReviewNextFile(page, diff.file))
 
     report(
       {
-        endToEndInitialContentObservedMs: initialContentObservedMs,
-        ...metrics,
-        deliveredDeltas: delivered,
-        pendingDeltas: fixture.transport.pendingCount(),
+        open,
+        switches,
       },
       {
-        cpuThrottle,
-        profileCPU,
-        profileVisual,
-        minimal,
-        queuedDeltas: deltas.length,
         historyTurns,
-        eventBatch,
+        reviewDiffs: diffs.length,
       },
     )
-
-    await profile.reset()
   })
 })
+
+async function runTimelineStreamBenchmark(page: Page, options: TimelineStreamOptions) {
+  const completionTimeoutMs = Number(process.env.TIMELINE_COMPLETION_TIMEOUT_MS ?? 420_000)
+  const cpuThrottle = Number(process.env.TIMELINE_CPU_THROTTLE ?? 30)
+  const deltaCount = Number(process.env.TIMELINE_DELTA_COUNT ?? 160)
+  const historyTurns = Number(process.env.TIMELINE_HISTORY_TURNS ?? 320)
+  const eventBatch = Number(process.env.TIMELINE_EVENT_BATCH ?? 1)
+  const minimal = process.env.TIMELINE_MINIMAL === "1"
+  const profileCPU = process.env.TIMELINE_CPU_PROFILE === "1"
+  const profileVisual = !minimal && profileCPU && process.env.TIMELINE_VISUAL_PROFILE !== "0"
+  const diffs = options.reviewDiffs || options.reviewPane ? createReviewDiffs() : undefined
+  const fixture = await setupTimelineBenchmark(page, {
+    historyTurns,
+    eventBatch,
+    newLayoutDesigns: options.newLayoutDesigns,
+    // Turn diffs exercise timeline data cost; the pane-open scenario serves the same
+    // diffs through the default git mode so it works across review implementations.
+    turnDiffs: options.reviewDiffs ? diffs : undefined,
+    vcsDiff: options.reviewPane ? diffs : undefined,
+  })
+
+  fixture.transport.enqueue(buildInitialStreamEvent(deltaCount))
+  const contentStart = performance.now()
+  await expect(fixture.text).toBeVisible()
+  await expect(fixture.text).toContainText("Implementation plan")
+  const initialContentObservedMs = performance.now() - contentStart
+  await fixture.scrollToBottom()
+  await fixture.waitForStableGeometry()
+
+  const reviewPane = options.reviewPane && diffs ? await measureReviewPaneLoad(page, diffs[0]!.file) : undefined
+  if (reviewPane) await fixture.waitForStableGeometry()
+
+  const profile = await startTimelineProfile(page, { cpuThrottle, profileCPU })
+  await installTimelineStreamProbe(page, { textPartID, finalIndex: deltaCount, profileVisual, minimal })
+  const deltas = buildStreamDeltaEvents(deltaCount)
+  await startTimelineStreamProbe(page)
+  fixture.transport.enqueue(deltas)
+
+  await page.waitForFunction(
+    (finalIndex) =>
+      (
+        window as Window & {
+          __timelineStreamBenchmark?: { applied: { index: number }[] }
+        }
+      ).__timelineStreamBenchmark?.applied.some((value) => value.index === finalIndex),
+    deltaCount,
+    { timeout: completionTimeoutMs },
+  )
+  await expect(fixture.text).toContainText("benchmark-complete")
+  await expect(fixture.text).toContainText("Streaming")
+  await fixture.waitForStableGeometry()
+  const metrics = await collectTimelineStreamMetrics(page, {
+    textPartID,
+    finalIndex: deltaCount,
+    navigations: benchmarkDiagnostics(page).navigations,
+  })
+  const delivered = deltas.length - fixture.transport.pendingCount()
+  await profile.stop()
+
+  const result = {
+    metrics: {
+      endToEndInitialContentObservedMs: initialContentObservedMs,
+      ...metrics,
+      deliveredDeltas: delivered,
+      pendingDeltas: fixture.transport.pendingCount(),
+      reviewPane: reviewPane ?? null,
+    },
+    context: {
+      cpuThrottle,
+      profileCPU,
+      profileVisual,
+      minimal,
+      queuedDeltas: deltas.length,
+      historyTurns,
+      eventBatch,
+      newLayoutDesigns: options.newLayoutDesigns === true,
+      reviewPane: options.reviewPane === true ? "open" : "closed",
+      reviewDiffs: diffs?.length ?? 0,
+    },
+  }
+
+  await profile.reset()
+  return result
+}
+
+async function measureReviewPaneLoad(page: Page, file: string) {
+  // Default git mode reads the mocked /vcs/diff data, so opening the pane is enough
+  // and the flow works across review pane implementations.
+  await installReviewPaneProbe(page, { file })
+  await startReviewPaneProbe(page)
+  await page.getByRole("button", { name: "Toggle review" }).click()
+  await expect(page.locator("#review-panel")).toBeVisible()
+  return collectReviewPaneProbe(page)
+}
+
+async function measureReviewNextFile(page: Page, file: string) {
+  await installReviewPaneProbe(page, { file })
+  await startReviewPaneProbe(page)
+  await page.getByRole("button", { name: "Next file" }).click()
+  return collectReviewPaneProbe(page)
+}
+
+async function installReviewPaneProbe(page: Page, input: { file: string }) {
+  await page.evaluate((input) => {
+    const samples: ReviewPaneSample[] = []
+    const basename = input.file.split(/[\\/]/).at(-1) ?? input.file
+    let started: number | undefined
+    let running = true
+
+    const paneState = () => {
+      const panel = document.querySelector<HTMLElement>("#review-panel")
+      const review = panel?.querySelector<HTMLElement>('[data-component="session-review-v2"]')
+      const rect = (review ?? panel)?.getBoundingClientRect()
+      const text = panel?.textContent ?? ""
+      const previewHeader = panel?.querySelector<HTMLElement>(
+        '[data-slot="session-review-v2-file-header"]',
+      )?.textContent
+      const header = previewHeader ?? text
+      const viewers = panel ? [...panel.querySelectorAll<HTMLElement>('[data-component="file"][data-mode="diff"]')] : []
+      const codeBlocks = panel?.querySelectorAll("code").length ?? 0
+      const diffLines = viewers.reduce(
+        (sum, viewer) =>
+          sum +
+          (viewer.shadowRoot?.querySelectorAll("[data-line]").length ?? viewer.querySelectorAll("[data-line]").length),
+        0,
+      )
+      const panelVisible =
+        !!panel && panel.getAttribute("aria-hidden") !== "true" && !!rect && rect.width > 0 && rect.height > 0
+      return {
+        panelVisible,
+        header: header.slice(0, 500),
+        diffViewers: viewers.length,
+        diffLines,
+        codeBlocks,
+        ready:
+          panelVisible &&
+          header.includes(basename) &&
+          (viewers.length > 0 || text.includes("+3") || diffLines > 0 || codeBlocks > 0),
+      }
+    }
+
+    const sample = () => {
+      if (!running || started === undefined) return
+      requestAnimationFrame(() => {
+        setTimeout(() => {
+          if (!running || started === undefined) return
+          samples.push({ observedAtMs: performance.now() - started, ...paneState() })
+          if (performance.now() - started < 10_000) sample()
+        }, 0)
+      })
+    }
+
+    ;(window as Window & { __reviewPaneProbe?: ReviewPaneProbe }).__reviewPaneProbe = {
+      samples,
+      start: () => {
+        started = performance.now()
+        performance.mark("opencode.review-pane.click")
+        sample()
+      },
+      stop: () => {
+        running = false
+      },
+    }
+  }, input)
+}
+
+async function startReviewPaneProbe(page: Page) {
+  await page.evaluate(() => {
+    ;(window as Window & { __reviewPaneProbe?: ReviewPaneProbe }).__reviewPaneProbe!.start()
+  })
+}
+
+async function collectReviewPaneProbe(page: Page) {
+  await page.waitForFunction((streak) => {
+    const samples = (window as Window & { __reviewPaneProbe?: ReviewPaneProbe }).__reviewPaneProbe?.samples
+    if (!samples) return false
+    return samples.some((_, index) => {
+      const stable = samples.slice(index, index + streak)
+      return stable.length === streak && stable.every((sample) => sample.ready)
+    })
+  }, reviewReadyStreak)
+
+  const samples = await page.evaluate(() => {
+    const probe = (window as Window & { __reviewPaneProbe?: ReviewPaneProbe }).__reviewPaneProbe!
+    probe.stop()
+    return probe.samples
+  })
+  return { summary: summarizeReviewPaneSamples(samples), samples }
+}
+
+function summarizeReviewPaneSamples(samples: ReviewPaneSample[]) {
+  const firstReady = samples.find((sample) => sample.ready)
+  const stableIndex = samples.findIndex((_, index) => {
+    const stable = samples.slice(index, index + reviewReadyStreak)
+    return stable.length === reviewReadyStreak && stable.every((sample) => sample.ready)
+  })
+  return {
+    samples: samples.length,
+    firstReadyObservedMs: firstReady?.observedAtMs ?? null,
+    stableReadyObservedMs: stableIndex === -1 ? null : samples[stableIndex + reviewReadyStreak - 1]!.observedAtMs,
+    notReadySamples: samples.filter((sample) => !sample.ready).length,
+    maxDiffViewers: Math.max(0, ...samples.map((sample) => sample.diffViewers)),
+    maxDiffLines: Math.max(0, ...samples.map((sample) => sample.diffLines)),
+    maxCodeBlocks: Math.max(0, ...samples.map((sample) => sample.codeBlocks)),
+  }
+}

packages/app/e2e/performance/timeline/timeline-test-helpers.ts

@@ -21,7 +21,10 @@ export async function installTimelineSettings(page: Page) {
 
 export function mockStressTimeline(
   page: Page,
-  input?: { onMessages?: (input: { sessionID: string; before?: string; phase: "start" | "end" }) => void },
+  input?: {
+    onMessages?: (input: { sessionID: string; before?: string; phase: "start" | "end" }) => void
+    vcsDiff?: unknown[]
+  },
 ) {
   return mockOpenCodeServer(page, {
     sessions: fixture.sessions,
@@ -30,6 +33,7 @@ export function mockStressTimeline(
     project: fixture.project,
     pageMessages,
     onMessages: input?.onMessages,
+    vcsDiff: input?.vcsDiff,
   })
 }
 
@@ -45,7 +49,7 @@ export async function installStressSessionTabs(page: Page, input?: { draftID?: s
         }),
       )
       localStorage.setItem(
-        "opencode.global.dat:tabs",
+        "opencode.window.browser.dat:tabs",
         JSON.stringify([
           ...sessionIDs.map((sessionId) => ({
             type: "session",
@@ -78,3 +82,53 @@ export function stressDraftHref(draftID: string) {
 function stressServer() {
   return `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
 }
+
+export function createReviewDiffs() {
+  return Array.from({ length: Number(process.env.REVIEW_PANE_DIFF_COUNT ?? 72) }, (_, index) => {
+    const lines = index % 3 === 0 ? 300 : index % 3 === 1 ? 120 : 38
+    const file = `src/review/generated-${String(index).padStart(3, "0")}.ts`
+    const before = reviewSource(index, lines)
+    const after = before
+      .replace(`value_${index}_4`, `updated_${index}_4`)
+      .replace(
+        `value_${index}_${Math.max(8, Math.floor(lines / 2))}`,
+        `updated_${index}_${Math.max(8, Math.floor(lines / 2))}`,
+      )
+      .replace(`value_${index}_${lines - 4}`, `updated_${index}_${lines - 4}`)
+    return {
+      file,
+      patch: reviewPatch(file, before, after),
+      additions: 3,
+      deletions: 3,
+      status: "modified" as const,
+    }
+  })
+}
+
+function reviewSource(seed: number, lines: number) {
+  return Array.from(
+    { length: lines },
+    (_, index) => `export const value_${seed}_${index} = "${reviewWords(seed + index, index % 5 === 0 ? 180 : 42)}"`,
+  ).join("\n")
+}
+
+function reviewPatch(file: string, before: string, after: string) {
+  const beforeLines = before.split("\n")
+  const afterLines = after.split("\n")
+  return [
+    `diff --git a/${file} b/${file}`,
+    `--- a/${file}`,
+    `+++ b/${file}`,
+    `@@ -1,${beforeLines.length} +1,${afterLines.length} @@`,
+    ...beforeLines.flatMap((line, index) => {
+      const next = afterLines[index]!
+      if (line === next) return [` ${line}`]
+      return [`-${line}`, `+${next}`]
+    }),
+  ].join("\n")
+}
+
+function reviewWords(seed: number, length: number) {
+  const words = ["alpha", "bravo", "charlie", "delta", "echo", "foxtrot", "golf", "hotel", "india", "juliet"]
+  return Array.from({ length: Math.ceil(length / 7) }, (_, index) => words[(seed + index * 3) % words.length]).join(" ")
+}

packages/app/e2e/performance/unit/mock-server.test.ts

@@ -0,0 +1,46 @@
+import { expect, test } from "bun:test"
+import type { Page, Route } from "@playwright/test"
+import { mockOpenCodeServer } from "../../utils/mock-server"
+
+test("applies message latency after a list response gate is released", async () => {
+  const events: string[] = []
+  const gate = Promise.withResolvers<void>()
+  let handler: ((route: Route) => Promise<void>) | undefined
+  const page = {
+    route: (_url: string, callback: (route: Route) => Promise<void>) => {
+      handler = callback
+      return Promise.resolve()
+    },
+  } as unknown as Page
+  await mockOpenCodeServer(page, {
+    provider: {},
+    directory: "C:/OpenCode",
+    project: {},
+    sessions: [{ id: "session" }],
+    messageDelay: 25,
+    beforeMessagesResponse: () => {
+      events.push("before")
+      return gate.promise
+    },
+    onMessages: (request) => events.push(request.phase),
+    pageMessages: () => {
+      events.push("page")
+      return { items: [] }
+    },
+  })
+
+  const response = handler!({
+    request: () => ({ url: () => "http://127.0.0.1:4096/session/session/message" }),
+    fulfill: () => {
+      events.push("fulfill")
+      return Promise.resolve()
+    },
+  } as unknown as Route)
+  expect(events).toEqual(["start", "before"])
+
+  const released = performance.now()
+  gate.resolve()
+  await response
+  expect(performance.now() - released).toBeGreaterThanOrEqual(20)
+  expect(events).toEqual(["start", "before", "page", "end", "fulfill"])
+})

packages/app/e2e/performance/unit/session-tab-switch-metrics.test.ts

@@ -52,3 +52,35 @@ test("reports missing correctness without throwing", () => {
   expect(result.firstCorrectObservedMs).toBeNull()
   expect(result.stableObservedMs).toBeNull()
 })
+
+test("requires an explicitly tracked part to be visible", () => {
+  const result = classifySessionSwitch([
+    {
+      observedAtMs: 16,
+      destination: ["destination"],
+      source: [],
+      hasVisibleRows: true,
+      last: true,
+      requiredPartVisible: false,
+      bottomErrorPx: 0,
+    },
+  ])
+
+  expect(result.firstCorrectObservedMs).toBeNull()
+})
+
+test("can measure content correctness without requiring a bottom anchor", () => {
+  const result = classifySessionSwitch([
+    {
+      observedAtMs: 16,
+      destination: ["destination"],
+      source: [],
+      hasVisibleRows: true,
+      last: true,
+      requiredPartVisible: true,
+      bottomAnchorRequired: false,
+    },
+  ])
+
+  expect(result.firstCorrectObservedMs).toBe(16)
+})

packages/app/e2e/performance/unit/session-tab-switch-probe.test.ts

@@ -0,0 +1,55 @@
+import { expect, test } from "bun:test"
+import type { Page } from "@playwright/test"
+import { measureSessionSwitch } from "../timeline/session-tab-switch-probe"
+
+function testPage(waitFailure?: Error) {
+  const stops: unknown[] = []
+  const page = {
+    evaluate: async (_callback: unknown, input?: unknown) => {
+      if (input) return
+      stops.push(undefined)
+    },
+    waitForFunction: async () => {
+      if (waitFailure) throw waitFailure
+    },
+  } as unknown as Page
+  return { page, stops }
+}
+
+function input(run: () => Promise<void>) {
+  return {
+    destinationIDs: ["destination"],
+    sourceIDs: ["source"],
+    lastID: "destination",
+    href: "/session/destination",
+    switch: run,
+  }
+}
+
+test("stops sampling when the session switch fails", async () => {
+  const failure = new Error("switch failed")
+  const context = testPage()
+
+  await expect(
+    measureSessionSwitch(
+      context.page,
+      input(async () => Promise.reject(failure)),
+    ),
+  ).rejects.toBe(failure)
+
+  expect(context.stops).toHaveLength(1)
+})
+
+test("stops sampling when the stable wait fails", async () => {
+  const failure = new Error("stable wait failed")
+  const context = testPage(failure)
+
+  await expect(
+    measureSessionSwitch(
+      context.page,
+      input(async () => {}),
+    ),
+  ).rejects.toBe(failure)
+
+  expect(context.stops).toHaveLength(1)
+})

packages/app/e2e/performance/unit/visual-stability.test.ts

@@ -0,0 +1,392 @@
+import { expect, test } from "bun:test"
+import {
+  analyzeVisualStability,
+  analyzeVisualStabilityByMarker,
+  type VisualStabilityTrace,
+} from "../../utils/visual-stability"
+import { analyzeVisualObservations } from "../../utils/visual-stability/analyzer"
+import { legacyVisualPlan, visualPlan, type VisualInvariant } from "../../utils/visual-stability/invariant"
+import { defineVisualRegions, mapVisualRegions } from "../../utils/visual-stability/regions"
+
+function trace(samples: VisualStabilityTrace["samples"]): VisualStabilityTrace {
+  return { markers: [], samples }
+}
+
+test("accepts continuous visible motion", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        frame(0, region({ width: 80, bottom: 40 }), region({ top: 40, bottom: 60 })),
+        frame(16, region({ width: 75, bottom: 45 }), region({ top: 45, bottom: 65 })),
+        frame(32, region({ width: 70, bottom: 50 }), region({ top: 50, bottom: 70 })),
+      ]),
+      { flow: ["changing", "following"] },
+    ),
+  ).toEqual([])
+})
+
+test("reports repeated geometry reversals", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      frame(0, region({ width: 80 })),
+      frame(16, region({ width: 60 })),
+      frame(32, region({ width: 78 })),
+      frame(48, region({ width: 62 })),
+    ]),
+  )
+
+  expect(issues.some((issue) => issue.includes("changing width reversed 2 times"))).toBe(true)
+})
+
+test("reports visible blanking, label reversal, and overlap", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      frame(0, region({ label: "Exploring", opacity: 1, bottom: 40 }), region({ top: 40, bottom: 60 })),
+      frame(16, region({ label: "Explored", opacity: 0.2, bottom: 50 }), region({ top: 49, bottom: 69 })),
+      frame(32, region({ label: "Exploring", opacity: 1, bottom: 50 }), region({ top: 50, bottom: 70 })),
+    ]),
+    { flow: ["changing", "following"] },
+  )
+
+  expect(issues.some((issue) => issue.includes("opacity fell to 0.2"))).toBe(true)
+  expect(issues.some((issue) => issue.includes("label reverted"))).toBe(true)
+  expect(issues.some((issue) => issue.includes("overlapped following by 1px"))).toBe(true)
+})
+
+test("reports duplicate regions and unexpected remounts", () => {
+  const issues = analyzeVisualStability(
+    trace([frame(0, region({ node: 1 })), frame(16, region({ node: 2, count: 2 })), frame(32, region({ node: 2 }))]),
+    { stable: ["changing"], unique: ["changing"] },
+  )
+
+  expect(issues.some((issue) => issue.includes("changing appeared 2 times"))).toBe(true)
+  expect(issues.some((issue) => issue.includes("changing remounted"))).toBe(true)
+})
+
+test("reports bottom anchor loss but permits movement while scrolled away", () => {
+  const anchored = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { changing: region() }, viewport: viewport(0) },
+      { at: 16, regions: { changing: region() }, viewport: viewport(24) },
+    ]),
+    { preserveBottomAnchor: true },
+  )
+  const away = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { changing: region() }, viewport: viewport(80) },
+      { at: 16, regions: { changing: region() }, viewport: viewport(104) },
+    ]),
+    { preserveBottomAnchor: true },
+  )
+
+  expect(anchored.some((issue) => issue.includes("bottom anchor moved to 24px"))).toBe(true)
+  expect(away).toEqual([])
+})
+
+test("reports up down up movement while preserving a bottom anchor", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { changing: region({ top: 200, bottom: 240 }) }, viewport: viewport(0) },
+      { at: 16, regions: { changing: region({ top: 180, bottom: 220 }) }, viewport: viewport(0) },
+      { at: 32, regions: { changing: region({ top: 196, bottom: 236 }) }, viewport: viewport(0) },
+      { at: 48, regions: { changing: region({ top: 176, bottom: 216 }) }, viewport: viewport(0) },
+    ]),
+    { preserveBottomAnchor: true, maxPositionReversals: 0 },
+  )
+
+  expect(issues.some((issue) => issue.includes("changing top reversed 2 times"))).toBe(true)
+  expect(issues.some((issue) => issue.includes("changing bottom reversed 2 times"))).toBe(true)
+})
+
+test("accepts monotonic upward movement while preserving a bottom anchor", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        { at: 0, regions: { changing: region({ top: 200, bottom: 240 }) }, viewport: viewport(0) },
+        { at: 16, regions: { changing: region({ top: 190, bottom: 230 }) }, viewport: viewport(0) },
+        { at: 32, regions: { changing: region({ top: 180, bottom: 220 }) }, viewport: viewport(0) },
+      ]),
+      { preserveBottomAnchor: true, maxPositionReversals: 0 },
+    ),
+  ).toEqual([])
+})
+
+test("ignores overlap entirely outside the clipped timeline viewport", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        {
+          at: 0,
+          regions: {
+            changing: region({ top: -200, bottom: -100 }),
+            following: region({ top: -150, bottom: -50 }),
+          },
+          viewport: viewport(0),
+        },
+      ]),
+      { flow: ["changing", "following"] },
+    ),
+  ).toEqual([])
+})
+
+test("reports visible anchor movement while allowing virtual scrollbar movement", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { anchor: region({ top: 100, bottom: 120 }) }, viewport: { ...viewport(100), scrollTop: 40 } },
+      { at: 16, regions: { anchor: region({ top: 100, bottom: 120 }) }, viewport: { ...viewport(120), scrollTop: 60 } },
+    ]),
+    { fixed: ["anchor"] },
+  )
+
+  expect(issues).toEqual([])
+
+  const moved = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { anchor: region({ top: 100, bottom: 120 }) }, viewport: viewport(100) },
+      { at: 16, regions: { anchor: region({ top: 112, bottom: 132 }) }, viewport: viewport(100) },
+    ]),
+    { fixed: ["anchor"] },
+  )
+  expect(moved.some((issue) => issue.includes("anchor moved 12px in the viewport"))).toBe(true)
+})
+
+test("analyzes each marked event independently", () => {
+  const input: VisualStabilityTrace = {
+    markers: [
+      { at: 10, label: "grow" },
+      { at: 40, label: "shrink" },
+    ],
+    samples: [
+      frame(0, region({ top: 100 })),
+      frame(16, region({ top: 90 })),
+      frame(32, region({ top: 80 })),
+      frame(48, region({ top: 90 })),
+      frame(64, region({ top: 100 })),
+    ],
+  }
+
+  expect(analyzeVisualStability(input, { maxPositionReversals: 0 })).toContain("changing top reversed 1 times")
+  expect(
+    analyzeVisualStabilityByMarker(input, {
+      maxPositionReversals: 0,
+      motion: ["changing"],
+      aggregateMotion: false,
+    }),
+  ).toEqual([])
+})
+
+test("reports cross-event motion reversals by default", () => {
+  const input: VisualStabilityTrace = {
+    markers: [
+      { at: 10, label: "up" },
+      { at: 40, label: "down" },
+    ],
+    samples: [
+      frame(0, region({ top: 100 })),
+      frame(16, region({ top: 90 })),
+      frame(32, region({ top: 80 })),
+      frame(48, region({ top: 90 })),
+      frame(64, region({ top: 100 })),
+    ],
+  }
+
+  expect(analyzeVisualStabilityByMarker(input, { maxPositionReversals: 0 })).toContain("changing top reversed 1 times")
+})
+
+test("reports regions rendered in the wrong flow order", () => {
+  const issues = analyzeVisualStability(
+    trace([frame(0, region({ top: 100, bottom: 120 }), region({ top: 60, bottom: 80 }))]),
+    { flow: ["changing", "following"] },
+  )
+
+  expect(issues.some((issue) => issue.includes("changing rendered after following"))).toBe(true)
+})
+
+test("uses painted bounds instead of clipped layout overflow", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        frame(
+          0,
+          region({ top: 100, bottom: 140, height: 40, layoutTop: 100, layoutBottom: 300 }),
+          region({ top: 140, bottom: 180 }),
+        ),
+      ]),
+      { flow: ["changing", "following"] },
+    ),
+  ).toEqual([])
+})
+
+test("does not report disappearance when a present row moves outside the viewport", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        frame(0, region({ visible: true })),
+        frame(16, region({ visible: false, inViewport: false, top: -100, bottom: -80 })),
+        frame(32, region({ visible: true })),
+      ]),
+    ),
+  ).toEqual([])
+})
+
+test("reports an in-viewport transparent frame between visible frames", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      frame(0, region()),
+      frame(16, region({ visible: false, opacity: 0, inViewport: true })),
+      frame(32, region()),
+    ]),
+  )
+
+  expect(issues.some((issue) => issue.includes("blanked between visible frames"))).toBe(true)
+})
+
+test("reports an in-viewport display-none frame between visible frames", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      frame(0, region()),
+      frame(16, region({ visible: false, width: 0, height: 0, inViewport: true, cssHidden: true })),
+      frame(32, region()),
+    ]),
+  )
+
+  expect(issues.some((issue) => issue.includes("blanked between visible frames"))).toBe(true)
+})
+
+test("can limit motion analysis to unaffected regions", () => {
+  expect(
+    analyzeVisualStability(
+      trace([
+        frame(0, region({ height: 20 }), region()),
+        frame(16, region({ height: 40 }), region()),
+        frame(32, region({ height: 30 }), region()),
+      ]),
+      { motion: ["following"] },
+    ),
+  ).toEqual([])
+})
+
+test("reports a blank frame across replacement surfaces", () => {
+  const issues = analyzeVisualStability(
+    {
+      markers: [],
+      samples: [
+        { at: 0, regions: { thinking: region(), error: region({ present: false, visible: false }) } },
+        {
+          at: 16,
+          regions: {
+            thinking: region({ present: false, visible: false }),
+            error: region({ present: false, visible: false }),
+          },
+        },
+        { at: 32, regions: { thinking: region({ present: false, visible: false }), error: region() } },
+      ],
+    },
+    { continuousAny: [["thinking", "error"]] },
+  )
+
+  expect(issues.some((issue) => issue.includes("thinking | error blanked"))).toBe(true)
+})
+
+test("reports failure to acquire the bottom anchor", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      { at: 0, regions: { changing: region() }, viewport: viewport(600) },
+      { at: 16, regions: { changing: region() }, viewport: viewport(120) },
+    ]),
+    { acquireBottomAnchor: true },
+  )
+
+  expect(issues.some((issue) => issue.includes("did not acquire bottom anchor"))).toBe(true)
+})
+
+test("reports a required region that never renders", () => {
+  const issues = analyzeVisualStability(
+    trace([
+      {
+        at: 0,
+        regions: { changing: region({ present: false, visible: false }) },
+      },
+    ]),
+    { required: ["changing"] },
+  )
+
+  expect(issues).toContain("changing never rendered")
+})
+
+test("preserves typed region names while mapping definitions", () => {
+  const regions = defineVisualRegions({
+    changing: { selector: "[data-changing]" },
+    following: { selector: "[data-following]", closest: "[data-row]" },
+  })
+  const selectors = mapVisualRegions(regions, (region) => region.selector)
+
+  expect(selectors).toEqual({ changing: "[data-changing]", following: "[data-following]" })
+  const name: keyof typeof selectors = "changing"
+  expect(name).toBe("changing")
+})
+
+test("evaluates the typed invariant algebra over explicit observations", () => {
+  const regions = defineVisualRegions({
+    changing: { selector: "[data-changing]" },
+    following: { selector: "[data-following]" },
+  })
+  const invariants = [
+    { type: "required", regions: ["changing"] },
+    { type: "flow", regions: ["changing", "following"] },
+  ] satisfies VisualInvariant<keyof typeof regions>[]
+  // @ts-expect-error Plans reject names that are not in the region definition.
+  const invalid = { type: "required", regions: ["missing"] } satisfies VisualInvariant<keyof typeof regions>
+  const plan = visualPlan(regions, invariants, { perMarker: true })
+
+  expect(invalid.regions).toEqual(["missing"])
+  expect(plan.perMarker).toBe(true)
+  expect(analyzeVisualObservations([frame(0, region({ bottom: 50 }), region({ top: 49, bottom: 69 }))], plan)).toEqual([
+    "changing overlapped following by 1px at 0ms",
+  ])
+})
+
+test("legacy plan adapter preserves analyzer messages and order", () => {
+  const input = trace([
+    frame(0, region({ label: "Exploring", opacity: 1, bottom: 40 }), region({ top: 40, bottom: 60 })),
+    frame(16, region({ label: "Explored", opacity: 0.2, bottom: 50 }), region({ top: 49, bottom: 69 })),
+    frame(32, region({ label: "Exploring", opacity: 1, bottom: 50 }), region({ top: 50, bottom: 70 })),
+  ])
+  const options = { flow: ["changing", "following"], stable: ["changing"] }
+
+  expect(analyzeVisualObservations(input.samples, legacyVisualPlan(options))).toEqual(
+    analyzeVisualStability(input, options),
+  )
+})
+
+function frame(
+  at: number,
+  changing: VisualStabilityTrace["samples"][number]["regions"][string],
+  following?: VisualStabilityTrace["samples"][number]["regions"][string],
+) {
+  return { at, regions: { changing, ...(following ? { following } : {}) } }
+}
+
+function region(input: Partial<VisualStabilityTrace["samples"][number]["regions"][string]> = {}) {
+  return {
+    present: true,
+    visible: true,
+    inViewport: true,
+    top: 0,
+    bottom: 20,
+    width: 100,
+    height: 20,
+    opacity: 1,
+    count: 1,
+    node: 1,
+    label: "",
+    text: "",
+    layoutTop: input.top ?? 0,
+    layoutBottom: input.bottom ?? 20,
+    ...input,
+  }
+}
+
+function viewport(distanceFromBottom: number) {
+  return { top: 0, bottom: 400, scrollTop: 100, scrollHeight: 500, clientHeight: 400, distanceFromBottom }
+}

packages/app/e2e/regression/cross-server-tab-close.spec.ts

@@ -14,7 +14,7 @@ test("closing the active server's last tab opens the remaining server tab", asyn
       localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
       localStorage.setItem("opencode.global.dat:server", JSON.stringify({ list: [serverB] }))
       localStorage.setItem(
-        "opencode.global.dat:tabs",
+        "opencode.window.browser.dat:tabs",
         JSON.stringify([
           { type: "session", server: "http://127.0.0.1:4096", sessionId: sessionA },
           { type: "session", server: serverB, sessionId: sessionB },
@@ -52,7 +52,7 @@ test("legacy session routes preserve an existing tab's server", async ({ page })
       localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
       localStorage.setItem("opencode.global.dat:server", JSON.stringify({ list: [serverB] }))
       localStorage.setItem(
-        "opencode.global.dat:tabs",
+        "opencode.window.browser.dat:tabs",
         JSON.stringify([{ type: "session", server: serverB, sessionId: sessionB }]),
       )
     },

packages/app/e2e/regression/new-session-panel-corner.spec.ts

@@ -0,0 +1,83 @@
+import { expect, test } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectAppVisible } from "../utils/waits"
+
+const draftID = "draft_new_session_panel_corner"
+const directory = "C:/OpenCode/NewSessionPanelCorner"
+const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+
+test.use({
+  viewport: { width: 935, height: 522 },
+  deviceScaleFactor: 1,
+})
+
+test("matches the rounded panel corners to the dark new-session background", async ({ page }, testInfo) => {
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: "proj_new_session_panel_corner",
+      worktree: directory,
+      vcs: "git",
+      name: "new-session-panel-corner",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: { all: [], connected: [], default: {} },
+    sessions: [],
+    pageMessages: () => ({ items: [] }),
+  })
+  await page.addInitScript(
+    ({ directory, draftID, server }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem("opencode-theme-id", "oc-2")
+      localStorage.setItem("opencode-color-scheme", "dark")
+      localStorage.setItem(
+        "opencode.global.dat:server",
+        JSON.stringify({
+          projects: { local: [{ worktree: directory, expanded: true }] },
+          lastProject: { local: directory },
+        }),
+      )
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify([{ type: "draft", draftID, server, directory }]),
+      )
+    },
+    { directory, draftID, server },
+  )
+
+  await page.goto(`/new-session?draftId=${draftID}`)
+  await expectAppVisible(page.locator('[data-component="prompt-input"]'))
+  await expect(page.locator("html")).toHaveAttribute("data-color-scheme", "dark")
+  const panel = page.locator('main div[class*="rounded-[10px]"][class*="overflow-hidden"]')
+  await expect(panel).toHaveCount(1)
+  const box = await panel.boundingBox()
+  if (!box) throw new Error("New-session panel bounds are unavailable")
+
+  const screenshot = await page.screenshot({ path: testInfo.outputPath("new-session-dark.png") })
+  const corners = await page.evaluate(
+    async ({ source, points }) => {
+      const image = new Image()
+      image.src = source
+      await image.decode()
+      const canvas = document.createElement("canvas")
+      canvas.width = image.naturalWidth
+      canvas.height = image.naturalHeight
+      const context = canvas.getContext("2d")
+      if (!context) throw new Error("2D canvas is unavailable")
+      context.drawImage(image, 0, 0)
+      return points.map((point) => Array.from(context.getImageData(point.x, point.y, 1, 1).data))
+    },
+    {
+      source: `data:image/png;base64,${screenshot.toString("base64")}`,
+      points: [
+        { x: Math.floor(box.x), y: Math.floor(box.y) },
+        { x: Math.ceil(box.x + box.width) - 1, y: Math.floor(box.y) },
+        { x: Math.floor(box.x), y: Math.ceil(box.y + box.height) - 1 },
+        { x: Math.ceil(box.x + box.width) - 1, y: Math.ceil(box.y + box.height) - 1 },
+      ],
+    },
+  )
+
+  expect(corners.every(([red, green, blue, alpha]) => red <= 8 && green <= 8 && blue <= 8 && alpha === 255)).toBe(true)
+})

packages/app/e2e/regression/prompt-thinking-level.spec.ts

@@ -66,7 +66,7 @@ test("shows the V2 thinking level control while relevant", async ({ page }) => {
   await expect(control).toBeVisible()
 
   await control.locator('[data-action="prompt-model-variant"]').click()
-  const high = page.getByRole("option", { name: "high" })
+  const high = page.getByRole("menuitemradio", { name: "high" })
   await expect(high).toBeVisible()
   await page.mouse.move(0, 0)
   await expect(control).toBeVisible()

packages/app/e2e/regression/remote-tab-busy.spec.ts

@@ -0,0 +1,109 @@
+import { expect, test, type Page, type Route } from "@playwright/test"
+import { base64Encode } from "@opencode-ai/core/util/encode"
+
+const serverA = "http://127.0.0.1:4096"
+const serverB = "http://127.0.0.1:4097"
+const sessionA = session("ses_server_a", "C:/server-a", "Server A session")
+const sessionB = session("ses_server_b", "/home/server-b", "Server B session")
+
+test("tab busy indicator reflects the tab server's own session status", async ({ page }) => {
+  await mockServers(page)
+  await page.addInitScript(
+    ({ serverA, serverB, sessionA, sessionB }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem("opencode.global.dat:server", JSON.stringify({ list: [serverB] }))
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify([
+          { type: "session", server: serverA, sessionId: sessionA },
+          { type: "session", server: serverB, sessionId: sessionB },
+        ]),
+      )
+    },
+    { serverA, serverB, sessionA: sessionA.id, sessionB: sessionB.id },
+  )
+
+  const hrefA = `/server/${base64Encode(serverA)}/session/${sessionA.id}`
+  const hrefB = `/server/${base64Encode(serverB)}/session/${sessionB.id}`
+  await page.goto(hrefA)
+  await expect(page.getByText(sessionA.title).first()).toBeVisible()
+
+  // Session B is busy on server B while server A stays the active server, so the
+  // busy indicator must come from the tab server's status, not the active server's.
+  const tabB = page.locator(`[data-titlebar-tab-slot]:has(a[href="${hrefB}"])`)
+  await expect(tabB.locator('[data-component="session-progress-indicator-v2"]')).toBeVisible()
+
+  const tabA = page.locator(`[data-titlebar-tab-slot]:has(a[href="${hrefA}"])`)
+  await expect(tabA.locator("[data-titlebar-tab-title]")).toHaveText(sessionA.title)
+  await expect(tabA.locator('[data-component="session-progress-indicator-v2"]')).toHaveCount(0)
+})
+
+function session(id: string, directory: string, title: string) {
+  return {
+    id,
+    slug: id,
+    projectID: `project-${id}`,
+    directory,
+    title,
+    version: "dev",
+    time: { created: 1, updated: 1 },
+  }
+}
+
+async function mockServers(page: Page) {
+  await page.route("**/*", async (route) => {
+    const url = new URL(route.request().url())
+    if (url.origin !== serverA && url.origin !== serverB) return route.fallback()
+    const current = url.origin === serverA ? sessionA : sessionB
+    const directory = url.searchParams.get("directory")
+    if (directory && directory !== current.directory) return json(route, { name: "InvalidDirectory" }, 500)
+    if (url.pathname === "/global/event" || url.pathname === "/event") return sse(route)
+    if (url.pathname === "/global/health") return json(route, { healthy: true })
+    if (url.pathname === "/session/status")
+      return json(route, url.origin === serverB ? { [sessionB.id]: { type: "busy" } } : {})
+    if (url.pathname === "/session") return json(route, [current])
+    if (url.pathname === `/session/${current.id}`) return json(route, current)
+    if (/^\/session\/[^/]+$/.test(url.pathname)) return json(route, { name: "NotFoundError" }, 404)
+    if (url.pathname === `/session/${current.id}/message`) return json(route, [])
+    if (/^\/session\/[^/]+\/(children|todo|diff)$/.test(url.pathname)) return json(route, [])
+    if (["/skill", "/command", "/lsp", "/formatter", "/permission", "/question", "/vcs/diff"].includes(url.pathname))
+      return json(route, [])
+    if (["/global/config", "/config", "/provider/auth", "/mcp"].includes(url.pathname)) return json(route, {})
+    if (url.pathname === "/provider")
+      return json(route, { all: [], connected: [], default: { providerID: "", modelID: "" } })
+    if (url.pathname === "/agent") return json(route, [{ name: "build", mode: "primary" }])
+    if (url.pathname === "/project" || url.pathname === "/project/current") {
+      const project = {
+        id: current.projectID,
+        worktree: current.directory,
+        vcs: "git",
+        time: { created: 1, updated: 1 },
+        sandboxes: [],
+      }
+      return json(route, url.pathname === "/project" ? [project] : project)
+    }
+    if (url.pathname === "/path")
+      return json(route, {
+        state: current.directory,
+        config: current.directory,
+        worktree: current.directory,
+        directory: current.directory,
+        home: current.directory,
+      })
+    if (url.pathname === "/vcs") return json(route, { branch: "main", default_branch: "main" })
+    return json(route, {})
+  })
+}
+
+function json(route: Route, body: unknown, status = 200) {
+  return route.fulfill({
+    status,
+    contentType: "application/json",
+    headers: { "access-control-allow-origin": "*" },
+    body: JSON.stringify(body),
+  })
+}
+
+function sse(route: Route) {
+  return route.fulfill({ status: 200, contentType: "text/event-stream", body: ": ok\n\n" })
+}

packages/app/e2e/regression/review-image-flash.spec.ts

@@ -0,0 +1,202 @@
+import { expect, test, type Page } from "@playwright/test"
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectAppVisible, expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/ReviewImageFlashRegression"
+const sessionID = "ses_review_image_flash_regression"
+const title = "Review image flash regression"
+const imageFile = "assets/preview.png"
+
+test("clicking an image file in the v2 review pane does not blank the panel", async ({ page }) => {
+  await openReview(page)
+  await installReviewFlashProbe(page)
+
+  await page.getByRole("button", { name: /preview\.png/ }).click()
+  await waitForReviewFlashProbe(page, 400)
+  const trace = await collectReviewFlashProbe(page)
+  const bad = trace.samples.filter((sample) => sample.blank || sample.blackCenter)
+
+  expect(trace.samples.length).toBeGreaterThan(0)
+  expect(
+    bad,
+    JSON.stringify({ bad: bad.slice(0, 8), first: trace.samples.slice(0, 8), last: trace.samples.slice(-4) }, null, 2),
+  ).toEqual([])
+})
+
+async function openReview(page: Page) {
+  await page.setViewportSize({ width: 960, height: 900 })
+  await page.addInitScript(() => {
+    localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+  })
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: "proj_review_image_flash_regression",
+      worktree: directory,
+      vcs: "git",
+      name: "review-image-flash-regression",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: { all: [], connected: [], default: {} },
+    sessions: [
+      {
+        id: sessionID,
+        slug: "review-image-flash-regression",
+        projectID: "proj_review_image_flash_regression",
+        directory,
+        title,
+        version: "dev",
+        time: { created: 1700000000000, updated: 1700000000000 },
+      },
+    ],
+    vcsDiff: [
+      {
+        file: "src/example.ts",
+        additions: 1,
+        deletions: 1,
+        status: "modified",
+        patch:
+          "diff --git a/src/example.ts b/src/example.ts\n--- a/src/example.ts\n+++ b/src/example.ts\n@@ -1 +1 @@\n-export const value = 'before'\n+export const value = 'after'\n",
+      },
+      {
+        file: imageFile,
+        patch: "",
+        additions: 1,
+        deletions: 0,
+        status: "added",
+      },
+    ],
+    fileContent: async (path) => {
+      if (path !== imageFile) return undefined
+      await new Promise((resolve) => setTimeout(resolve, 250))
+      return {
+        type: "binary",
+        content: "iVBORw0KGgo=",
+        encoding: "base64",
+        mimeType: "image/png",
+      }
+    },
+    fileList: (path) => {
+      if (!path) {
+        return [
+          { name: "assets", path: "assets", absolute: `${directory}/assets`, type: "directory", ignored: false },
+          { name: "src", path: "src", absolute: `${directory}/src`, type: "directory", ignored: false },
+        ]
+      }
+      if (path === "assets") {
+        return [
+          {
+            name: "preview.png",
+            path: imageFile,
+            absolute: `${directory}/${imageFile}`,
+            type: "file",
+            ignored: false,
+          },
+        ]
+      }
+      if (path === "src") {
+        return [
+          {
+            name: "example.ts",
+            path: "src/example.ts",
+            absolute: `${directory}/src/example.ts`,
+            type: "file",
+            ignored: false,
+          },
+        ]
+      }
+      return []
+    },
+    pageMessages: () => ({
+      items: [
+        {
+          info: {
+            id: "msg_review_image_flash_regression",
+            sessionID,
+            role: "user",
+            time: { created: 1700000000000 },
+            summary: { diffs: [] },
+            agent: "build",
+            model: { providerID: "opencode", modelID: "test" },
+          },
+          parts: [
+            {
+              id: "prt_review_image_flash_regression",
+              sessionID,
+              messageID: "msg_review_image_flash_regression",
+              type: "text",
+              text: "Review this change.",
+            },
+          ],
+        },
+      ],
+    }),
+  })
+
+  await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+  await expectSessionTitle(page, title)
+  await page.getByRole("button", { name: "Toggle review" }).click()
+  await expectAppVisible(page.locator('#review-panel [data-component="session-review-v2"]'))
+  await expectAppVisible(page.getByRole("button", { name: /preview\.png/ }))
+}
+
+async function installReviewFlashProbe(page: Page) {
+  await page.evaluate(() => {
+    const samples: Array<{
+      observedAtMs: number
+      blank: boolean
+      blackCenter: boolean
+      text: string
+      background: string
+    }> = []
+    const startedAt = performance.now()
+    const sample = () => {
+      const panel = document.querySelector<HTMLElement>('#review-panel [data-component="session-review-v2"]')
+      const rect = panel?.getBoundingClientRect()
+      const center = rect
+        ? document.elementFromPoint(rect.left + rect.width / 2, rect.top + rect.height / 2)
+        : undefined
+      const background = center instanceof Element ? getComputedStyle(center).backgroundColor : ""
+      samples.push({
+        observedAtMs: performance.now() - startedAt,
+        blank: !panel || panel.textContent?.trim().length === 0,
+        blackCenter: background === "rgb(0, 0, 0)",
+        text: panel?.textContent?.trim().slice(0, 80) ?? "",
+        background,
+      })
+      if (performance.now() - startedAt < 500) requestAnimationFrame(sample)
+    }
+    document.addEventListener(
+      "click",
+      (event) => {
+        const target = event.target instanceof Element ? event.target : undefined
+        if (!target?.closest('[data-slot="file-tree-v2-row"]')) return
+        requestAnimationFrame(sample)
+      },
+      { capture: true, once: true },
+    )
+    ;(window as Window & { __reviewImageFlash?: { samples: typeof samples; startedAt: number } }).__reviewImageFlash = {
+      samples,
+      startedAt,
+    }
+  })
+}
+
+async function waitForReviewFlashProbe(page: Page, durationMs: number) {
+  await page.waitForFunction((durationMs) => {
+    const state = (window as Window & { __reviewImageFlash?: { samples: unknown[]; startedAt: number } })
+      .__reviewImageFlash
+    return !!state && state.samples.length > 0 && performance.now() - state.startedAt >= durationMs
+  }, durationMs)
+}
+
+async function collectReviewFlashProbe(page: Page) {
+  return page.evaluate(() => {
+    return (window as Window & { __reviewImageFlash?: { samples: unknown[]; startedAt: number } }).__reviewImageFlash!
+  }) as Promise<{
+    startedAt: number
+    samples: Array<{ observedAtMs: number; blank: boolean; blackCenter: boolean; text: string; background: string }>
+  }>
+}

packages/app/e2e/regression/review-tab-switch.spec.ts

@@ -0,0 +1,147 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { expect, test, type Page } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectAppVisible, expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/ReviewTabSwitch"
+const projectID = "proj_review_tab_switch"
+const sessionA = "ses_review_tab_a"
+const sessionB = "ses_review_tab_b"
+const titleA = "Alpha session"
+const titleB = "Beta session"
+const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+const diffs = Array.from({ length: 2_740 }, (_, index) =>
+  fileDiff(`src/generated-${String(index).padStart(4, "0")}.ts`),
+)
+// Marks the review pane DOM node so a remount (fresh node) is detectable.
+const PROBE = "original"
+
+test.use({ viewport: { width: 1440, height: 900 } })
+
+// The v2 review pane's diff data is workspace-scoped: switching between session
+// tabs in the same workspace must update its parameters reactively instead of
+// tearing the pane down and remounting it (which flickers).
+test("keeps the v2 review pane mounted when switching session tabs in a workspace", async ({ page }) => {
+  await setup(page)
+
+  await page.goto(sessionHref(sessionA))
+  await expectSessionTitle(page, titleA)
+
+  await page.getByRole("button", { name: "Toggle review" }).click()
+  const reviewTab = page.getByRole("tab", { name: /Review/ })
+  const reviewTabPanel = page.getByRole("tabpanel", { name: /Review/ })
+  await expect(reviewTab).toHaveAttribute("aria-controls", "session-side-panel-review-tabpanel")
+  await expect(reviewTabPanel).toHaveAttribute("id", "session-side-panel-review-tabpanel")
+  const review = page.locator('#review-panel [data-component="session-review-v2"]')
+  await expectAppVisible(review)
+  await expectAppVisible(page.getByRole("button", { name: "generated-0000.ts" }))
+  await writeProbe(page)
+
+  await switchTab(page, titleB)
+  await expectSessionTitle(page, titleB)
+  await expectAppVisible(review)
+  await expectAppVisible(page.getByRole("button", { name: "generated-0000.ts" }))
+  expect(await readProbe(page)).toBe(PROBE)
+
+  await switchTab(page, titleA)
+  await expectSessionTitle(page, titleA)
+  await expectAppVisible(review)
+  await expectAppVisible(page.getByRole("button", { name: "generated-0000.ts" }))
+  expect(await readProbe(page)).toBe(PROBE)
+
+  const viewport = page.locator('#review-panel [data-slot="session-review-v2-sidebar-tree"] .scroll-view__viewport')
+  await viewport.hover()
+  await page.mouse.wheel(0, 100_000)
+  await expect
+    .poll(() => viewport.evaluate((element) => element.scrollHeight - element.clientHeight - element.scrollTop))
+    .toBeLessThanOrEqual(1)
+  await expect(page.getByRole("button", { name: "generated-2739.ts" })).toBeVisible()
+})
+
+type Probed = HTMLElement & { __e2eProbe?: string }
+
+async function switchTab(page: Page, title: string) {
+  await page.locator("[data-titlebar-tab-slot]", { hasText: title }).click()
+}
+
+async function writeProbe(page: Page) {
+  await page.locator('#review-panel [data-component="session-review-v2"]').evaluate((el, probe) => {
+    ;(el as Probed).__e2eProbe = probe
+  }, PROBE)
+}
+
+async function readProbe(page: Page) {
+  return page.locator('#review-panel [data-component="session-review-v2"]').evaluate((el) => (el as Probed).__e2eProbe)
+}
+
+async function setup(page: Page) {
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "review-tab-switch",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: { test: { id: "test", name: "Test", limit: { context: 200_000 } } },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "test" },
+    },
+    sessions: [session(sessionA, titleA, 1700000000000), session(sessionB, titleB, 1700000001000)],
+    vcsDiff: diffs,
+    pageMessages: () => ({ items: [] }),
+  })
+
+  await page.addInitScript(
+    ({ directory, server, sessions }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem(
+        "opencode.global.dat:server",
+        JSON.stringify({
+          projects: { local: [{ worktree: directory, expanded: true }] },
+          lastProject: { local: directory },
+        }),
+      )
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify(sessions.map((sessionId: string) => ({ type: "session", server, sessionId }))),
+      )
+    },
+    { directory, server, sessions: [sessionA, sessionB] },
+  )
+}
+
+function session(id: string, title: string, created: number) {
+  return {
+    id,
+    slug: id,
+    projectID,
+    directory,
+    title,
+    version: "dev",
+    time: { created, updated: created },
+  }
+}
+
+function sessionHref(sessionID: string) {
+  return `/server/${base64Encode(server)}/session/${sessionID}`
+}
+
+function fileDiff(file: string) {
+  return {
+    file,
+    additions: 1,
+    deletions: 1,
+    status: "modified",
+    patch: `diff --git a/${file} b/${file}\n--- a/${file}\n+++ b/${file}\n@@ -1 +1 @@\n-export const value = 'before'\n+export const value = 'after'\n`,
+  }
+}

packages/app/e2e/regression/review-terminal-stacked.spec.ts

@@ -0,0 +1,212 @@
+import { expect, test, type Page } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/ReviewTerminalStacked"
+const projectID = "proj_review_terminal_stacked"
+const sessionID = "ses_review_terminal_stacked"
+const title = "Review terminal stacked"
+const branchDiffs = [
+  fileDiff(".github/actions/setup-bun/action.yml", 7),
+  ...Array.from({ length: 2_739 }, (_, index) =>
+    fileDiff(`src/branch/generated-${String(index).padStart(4, "0")}.ts`, 100),
+  ),
+]
+
+test("keeps the review tree and terminal sized when both panels are open", async ({ page }) => {
+  test.setTimeout(120_000)
+  await page.setViewportSize({ width: 1400, height: 900 })
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "review-terminal-stacked",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: { test: { id: "test", name: "Test", limit: { context: 200_000 } } },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "test" },
+    },
+    sessions: [
+      {
+        id: sessionID,
+        slug: "review-terminal-stacked",
+        projectID,
+        directory,
+        title,
+        version: "dev",
+        time: { created: 1700000000000, updated: 1700000000000 },
+      },
+    ],
+    pageMessages: () => ({ items: [] }),
+  })
+  await page.route(/\/vcs(?:\?.*)?$/, (route) =>
+    route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify({ branch: "review-pane-performance", default_branch: "dev" }),
+    }),
+  )
+  await page.route("**/vcs/diff**", (route) =>
+    route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify(
+        new URL(route.request().url()).searchParams.get("mode") === "branch"
+          ? branchDiffs
+          : Array.from({ length: 7 }, (_, index) => fileDiff(`src/git-${index}.ts`, 1)),
+      ),
+    }),
+  )
+  await page.route("**/pty", (route) =>
+    route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify({ id: "pty_review_terminal", title: "Terminal 1" }),
+    }),
+  )
+  await page.route("**/pty/pty_review_terminal", (route) =>
+    route.fulfill({ status: 200, contentType: "application/json", body: "{}" }),
+  )
+  await page.routeWebSocket("**/pty/pty_review_terminal/connect", () => undefined)
+  await page.addInitScript(() => {
+    localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+    localStorage.setItem(
+      "opencode.global.dat:layout",
+      JSON.stringify({ review: { diffStyle: "split", panelOpened: true } }),
+    )
+  })
+
+  await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+  await expectSessionTitle(page, title)
+  await expect(page.locator("#review-panel")).toBeVisible()
+  await expectTree(page, 8, "git-0.ts")
+
+  await selectMode(page, "Git changes", "Branch changes")
+  await expect(page.getByRole("tab", { name: "Review 2740" })).toBeVisible()
+  await page.keyboard.press("Control+Backquote")
+  await expect(page.locator("#terminal-panel")).toBeVisible()
+  await expectTree(page, 2_745, "action.yml")
+  await expectStackGeometry(page)
+
+  const treeViewport = page.locator('#review-panel [data-slot="session-review-v2-sidebar-tree"] .scroll-view__viewport')
+  await treeViewport.hover()
+  await page.mouse.wheel(0, 100_000)
+  await expect
+    .poll(() => treeViewport.evaluate((element) => element.scrollHeight - element.clientHeight - element.scrollTop))
+    .toBeLessThanOrEqual(1)
+  const lastFile = page.getByRole("button", { name: "generated-2738.ts" })
+  await expect(lastFile).toBeVisible()
+  const bottomGap = await lastFile.evaluate((element) => {
+    const viewport = element.closest<HTMLElement>(".scroll-view__viewport")!.getBoundingClientRect()
+    return viewport.bottom - element.getBoundingClientRect().bottom
+  })
+  expect(bottomGap).toBeGreaterThanOrEqual(0)
+  expect(bottomGap).toBeLessThanOrEqual(16)
+  await selectMode(page, "Branch changes", "Git changes")
+  await expectTree(page, 8, "git-0.ts")
+  await selectMode(page, "Git changes", "Branch changes")
+  await expectTree(page, 2_745, "action.yml")
+
+  const filter = page.getByRole("searchbox", { name: "Filter files" })
+  await filter.fill("generated-2738")
+  await expectTree(page, 1, "generated-2738.ts")
+  await filter.fill("")
+  await expectTree(page, 2_745, "action.yml")
+
+  await page.getByRole("button", { name: "Toggle file tree" }).click()
+  await expect(page.locator('[data-slot="session-review-v2-sidebar"]')).toHaveAttribute("aria-hidden", "true")
+  await expect(page.locator('#review-panel [data-component="file-tree-v2"]')).toHaveCount(1)
+  await page.getByRole("button", { name: "Toggle file tree" }).click()
+  await expectTree(page, 2_745, "action.yml")
+
+  await page.keyboard.press("Control+Backquote")
+  await expect(page.locator("#terminal-panel")).toHaveCount(0)
+  await expectTree(page, 2_745, "action.yml")
+  await page.keyboard.press("Control+Backquote")
+  await expect(page.locator("#terminal-panel")).toBeVisible()
+  await expectTree(page, 2_745, "action.yml")
+
+  await page.getByRole("button", { name: "Toggle review" }).click()
+  await expect(page.locator("#review-panel")).toHaveAttribute("aria-hidden", "true")
+  await expect(page.locator('#review-panel [data-component="file-tree-v2"]')).toHaveCount(1)
+  await page.getByRole("button", { name: "Toggle review" }).click()
+  await expectTree(page, 2_745, "action.yml")
+  await page.setViewportSize({ width: 1_000, height: 700 })
+  await expectTree(page, 2_745, "action.yml")
+  await expectStackGeometry(page)
+  await page.setViewportSize({ width: 1_000, height: 120 })
+  await page.setViewportSize({ width: 1_400, height: 900 })
+  await expectTree(page, 2_745, "action.yml")
+  await expectStackGeometry(page)
+})
+
+async function selectMode(page: Page, current: string, next: string) {
+  await page.getByRole("button", { name: current }).click()
+  const option = page.getByRole("option", { name: next })
+  await expect(option).toBeVisible()
+  await option.click()
+}
+
+async function expectTree(page: Page, total: number, file: string) {
+  await expectMountedTree(page, total)
+  await expect(page.getByRole("button", { name: file })).toBeVisible()
+}
+
+async function expectMountedTree(page: Page, total: number) {
+  const tree = page.locator('#review-panel [data-component="file-tree-v2"]')
+  await expect(tree).toHaveAttribute("data-total-rows", String(total))
+  await expect
+    .poll(() => tree.evaluate((element) => element.querySelectorAll('[data-slot="file-tree-v2-row"]').length))
+    .toBeGreaterThan(0)
+  const state = await tree.evaluate((element) => ({
+    root: element.getBoundingClientRect().height,
+    viewport: element.closest<HTMLElement>(".scroll-view__viewport")!.getBoundingClientRect().height,
+    rows: element.querySelectorAll('[data-slot="file-tree-v2-row"]').length,
+  }))
+  expect(state.viewport).toBeGreaterThan(0)
+  expect(state.root).toBeGreaterThan(0)
+  expect(state.rows).toBeGreaterThan(0)
+  expect(state.rows).toBeLessThanOrEqual(60)
+}
+
+async function expectStackGeometry(page: Page) {
+  const geometry = await page.evaluate(() => {
+    const review = document.querySelector<HTMLElement>("#review-panel")!
+    const terminal = document.querySelector<HTMLElement>("#terminal-panel")!
+    const reviewParent = review.parentElement!.getBoundingClientRect()
+    const terminalParent = terminal.parentElement!.getBoundingClientRect()
+    return {
+      review: review.getBoundingClientRect().height,
+      reviewParent: reviewParent.height,
+      terminal: terminal.getBoundingClientRect().height,
+      terminalParent: terminalParent.height,
+    }
+  })
+  expect(Math.abs(geometry.review - geometry.reviewParent)).toBeLessThanOrEqual(1)
+  expect(Math.abs(geometry.terminal - geometry.terminalParent)).toBeLessThanOrEqual(1)
+}
+
+function base64Encode(value: string) {
+  return Buffer.from(value, "utf8").toString("base64").replace(/\+/g, "-").replace(/\//g, "_").replace(/=/g, "")
+}
+
+function fileDiff(file: string, additions: number) {
+  return {
+    file,
+    additions,
+    deletions: 0,
+    status: "modified",
+    patch: `diff --git a/${file} b/${file}\n--- a/${file}\n+++ b/${file}\n@@ -1 +1 @@\n-export const value = 'before'\n+export const value = 'after'\n`,
+  }
+}

packages/app/e2e/regression/session-request-docks.spec.ts

@@ -38,6 +38,29 @@ test("shows a pending question dock", async ({ page }) => {
   await expect(question.getByRole("radio", { name: /Extended/ })).toBeVisible()
   await expect(page.locator('[data-component="session-composer"]')).toHaveCount(0)
 
+  const rejectRequests: string[] = []
+  page.on("request", (request) => {
+    if (request.method() !== "POST") return
+    if (new URL(request.url()).pathname === "/question/question-request/reject") rejectRequests.push(request.url())
+  })
+
+  await question.locator('[data-component="icon-button"][data-icon="chevron-down"]').click()
+  await expect(question).toBeVisible()
+  await expect(question.getByText("Which implementation should be used?")).toBeVisible()
+  await expect(question.getByText("Select one answer")).toBeHidden()
+  await expect(question.getByRole("radio", { name: /Minimal/ })).toBeHidden()
+  await expect(question.getByRole("radio", { name: /Extended/ })).toBeHidden()
+  await expect(question.getByRole("button", { name: "Dismiss" })).toBeVisible()
+  await expect(question.getByRole("button", { name: "Submit" })).toBeVisible()
+  await expect(page.locator('[data-component="question-minimized-dock"]')).toHaveCount(0)
+  expect(rejectRequests).toEqual([])
+
+  await question.locator('[data-component="icon-button"][data-icon="chevron-down"]').click()
+  await expect(question).toBeVisible()
+  await expect(question.getByText("Which implementation should be used?")).toBeVisible()
+  await expect(question.getByRole("radio", { name: /Minimal/ })).toBeVisible()
+  expect(rejectRequests).toEqual([])
+
   await question.getByRole("radio", { name: /Minimal/ }).click()
   const reply = page.waitForRequest(
     (request) => request.method() === "POST" && new URL(request.url()).pathname === "/question/question-request/reply",

packages/app/e2e/regression/session-timeline-accessibility.spec.ts

@@ -0,0 +1,22 @@
+import { expect, test } from "@playwright/test"
+import { assistantMessage, setupTimeline, shell, userMessage } from "../performance/timeline-stability/fixture"
+
+test("space activates a focused timeline button instead of scrolling", async ({ page }) => {
+  const shellID = "prt_space_button_shell"
+  await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([shell(shellID, "completed", lines(5))])],
+    settings: { shellToolPartsExpanded: false },
+    reducedMotion: true,
+  })
+  const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+  const trigger = page.locator(`[data-timeline-part-id="${shellID}"] [data-slot="collapsible-trigger"]`)
+  await trigger.focus()
+  const before = await scroller.evaluate((element) => element.scrollTop)
+  await trigger.press("Space")
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  expect(await scroller.evaluate((element) => element.scrollTop)).toBe(before)
+})
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}

packages/app/e2e/regression/session-timeline-context-resize.spec.ts

@@ -1,6 +1,13 @@
 import { expect, test, type Page } from "@playwright/test"
 import { mockOpenCodeServer } from "../utils/mock-server"
 import { expectAppVisible, expectSessionTitle } from "../utils/waits"
+import {
+  analyzeVisualObservations,
+  defineVisualRegions,
+  startVisualProbe,
+  stopVisualProbe,
+  visualPlan,
+} from "../utils/visual-stability"
 
 const directory = "C:/OpenCode/ContextResizeRegression"
 const projectID = "proj_context_resize_regression"
@@ -36,6 +43,82 @@ test.describe("regression: session timeline context group resize", () => {
     expect(visibleOverlap).toEqual([])
     expect(samples.at(-1)?.expanded).toBe("true")
   })
+
+  test("paints a stable exploring to explored transition", async ({ page }) => {
+    const events: { directory: string; payload: Record<string, unknown> }[] = []
+    await page.setViewportSize({ width: 1400, height: 900 })
+    await mockServer(page, events, [
+      ...Array.from({ length: 8 }, (_, index) => turn(index, false)).flat(),
+      ...turn(10, true, "running"),
+    ])
+    await configurePage(page)
+
+    await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+    await expectSessionTitle(page, title)
+    const devtools = await page.context().newCDPSession(page)
+    await devtools.send("Emulation.setCPUThrottlingRate", { rate: 4 })
+    const context = page.locator(`[data-timeline-part-ids="${contextIDs.join(",")}"]`).first()
+    await expectAppVisible(context)
+    await expect(context.locator('[data-component="tool-status-title"]')).toHaveAttribute("aria-label", "Exploring")
+
+    const contextSelector = `[data-timeline-part-ids="${contextIDs.join(",")}"]`
+    const regions = defineVisualRegions({
+      status: {
+        selector: `${contextSelector} [data-component="tool-status-title"]`,
+        opacitySelectors: ['[data-slot="tool-status-active"]', '[data-slot="tool-status-done"]'],
+      },
+      context: { selector: contextSelector, closest: '[data-timeline-row="AssistantPart"]' },
+      following: {
+        selector: `[data-timeline-part-id="${followingTextID}"]`,
+        closest: '[data-timeline-row="AssistantPart"]',
+      },
+    })
+    await startVisualProbe(page, regions)
+    for (const [index, delay] of [120, 350, 80, 500].entries()) {
+      events.push({
+        directory,
+        payload: {
+          type: "message.part.updated",
+          properties: {
+            part: contextTool(
+              contextIDs[index]!,
+              id("msg_assistant", 10),
+              ["read", "glob", "grep", "list"][index]!,
+              [
+                { filePath: "src/recent-a.ts" },
+                { path: directory, pattern: "**/*.ts" },
+                { path: directory, pattern: "Explored" },
+                { path: "src" },
+              ][index]!,
+            ),
+          },
+        },
+      })
+      await page.waitForTimeout(delay)
+    }
+
+    await expect(context.locator('[data-component="tool-status-title"]')).toHaveAttribute("aria-label", "Explored")
+    await page.waitForTimeout(700)
+    const trace = await stopVisualProbe<keyof typeof regions>(page)
+    const labels = trace.samples
+      .map((sample) => sample.regions.status?.label)
+      .filter((value): value is string => !!value)
+      .filter((value, index, all) => value !== all[index - 1])
+    const issues = analyzeVisualObservations(
+      trace.samples,
+      visualPlan(regions, [
+        { type: "required", regions: ["context", "following"] },
+        { type: "opacity", regions: "all" },
+        { type: "continuity", regions: "all" },
+        { type: "motion", regions: "all" },
+        { type: "label-stability", regions: "all" },
+        { type: "flow", regions: ["context", "following"] },
+      ]),
+    )
+
+    expect(labels).toEqual(["Exploring", "Explored"])
+    expect(issues, JSON.stringify(trace.samples, null, 2)).toEqual([])
+  })
 })
 
 async function configurePage(page: Page) {
@@ -128,7 +211,7 @@ async function sampleExpansion(page: Page) {
   )
 }
 
-function turn(index: number, target: boolean): Message[] {
+function turn(index: number, target: boolean, status: "running" | "completed" = "completed"): Message[] {
   const userID = id("msg_user", index)
   const assistantID = id("msg_assistant", index)
   return [
@@ -163,10 +246,22 @@ function turn(index: number, target: boolean): Message[] {
       },
       parts: target
         ? [
-            contextTool(contextIDs[0]!, assistantID, "read", { filePath: "src/recent-a.ts", offset: 0, limit: 120 }),
-            contextTool(contextIDs[1]!, assistantID, "glob", { path: directory, pattern: "**/*.ts" }),
-            contextTool(contextIDs[2]!, assistantID, "grep", { path: directory, pattern: "Explored", include: "*.ts" }),
-            contextTool(contextIDs[3]!, assistantID, "list", { path: "src" }),
+            contextTool(
+              contextIDs[0]!,
+              assistantID,
+              "read",
+              { filePath: "src/recent-a.ts", offset: 0, limit: 120 },
+              status,
+            ),
+            contextTool(contextIDs[1]!, assistantID, "glob", { path: directory, pattern: "**/*.ts" }, status),
+            contextTool(
+              contextIDs[2]!,
+              assistantID,
+              "grep",
+              { path: directory, pattern: "Explored", include: "*.ts" },
+              status,
+            ),
+            contextTool(contextIDs[3]!, assistantID, "list", { path: "src" }, status),
             {
               id: followingTextID,
               sessionID,
@@ -188,7 +283,13 @@ function turn(index: number, target: boolean): Message[] {
   ]
 }
 
-function contextTool(partID: string, messageID: string, tool: string, input: Record<string, unknown>) {
+function contextTool(
+  partID: string,
+  messageID: string,
+  tool: string,
+  input: Record<string, unknown>,
+  status: "running" | "completed" = "completed",
+) {
   return {
     id: partID,
     sessionID,
@@ -197,7 +298,7 @@ function contextTool(partID: string, messageID: string, tool: string, input: Rec
     callID: `call_${partID}`,
     tool,
     state: {
-      status: "completed",
+      status,
       input,
       output: `Completed ${tool}.\n${"detail line\n".repeat(8)}`,
       title: input.filePath || input.path || input.pattern || "completed",
@@ -207,13 +308,19 @@ function contextTool(partID: string, messageID: string, tool: string, input: Rec
   }
 }
 
-async function mockServer(page: Page) {
+async function mockServer(
+  page: Page,
+  events: { directory: string; payload: Record<string, unknown> }[] = [],
+  fixtureMessages = messages,
+) {
   await mockOpenCodeServer(page, {
     directory,
     project: project(),
     provider: provider(),
     sessions: [session()],
-    pageMessages: () => ({ items: messages }),
+    pageMessages: () => ({ items: fixtureMessages }),
+    events: () => events.splice(0, 1),
+    eventRetry: 50,
   })
 }
 

packages/app/e2e/regression/session-timeline-context-state.spec.ts

@@ -0,0 +1,31 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("preserves a collapsed context group through count and status updates", async ({ page }) => {
+  const ids = ["prt_closed_01_read", "prt_closed_02_glob"]
+  const inputs = {
+    read: { filePath: "src/a.ts", offset: 0, limit: 120 },
+    glob: { path: ".", pattern: "**/*.ts" },
+  }
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage(
+        [toolPart(ids[0]!, "read", "running", inputs.read), toolPart(ids[1]!, "glob", "running", inputs.glob)],
+        { completed: false },
+      ),
+    ],
+  })
+  const group = page.locator(`[data-timeline-part-ids="${ids.join(",")}"]`)
+  const trigger = group.locator('[data-slot="collapsible-trigger"]')
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+  await timeline.send(partUpdated(toolPart(ids[0]!, "read", "completed", inputs.read)), 100)
+  await timeline.send(partUpdated(toolPart(ids[1]!, "glob", "completed", inputs.glob)), 300)
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+})

packages/app/e2e/regression/session-timeline-file-projection.spec.ts

@@ -0,0 +1,52 @@
+import { expect, test } from "@playwright/test"
+import { assistantMessage, setupTimeline, toolPart, userMessage } from "../performance/timeline-stability/fixture"
+
+test("renders completed write content", async ({ page }) => {
+  const id = "prt_file_projection_write"
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(id, "write", "completed", { filePath: "src/write.ts", content: "export const written = true\n" }),
+      ]),
+    ],
+    settings: { editToolPartsExpanded: true },
+  })
+
+  await expect(page.locator(`[data-timeline-part-id="${id}"] [data-component="write-content"]`)).toBeVisible()
+})
+
+test("renders a completed single-file patch", async ({ page }) => {
+  const id = "prt_file_projection_single_patch"
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(
+          id,
+          "apply_patch",
+          "completed",
+          { files: ["src/a.ts"] },
+          {
+            metadata: {
+              files: [
+                {
+                  filePath: "src/a.ts",
+                  relativePath: "src/a.ts",
+                  type: "update",
+                  additions: 1,
+                  deletions: 1,
+                  before: "export const value = 1\n",
+                  after: "export const value = 2\n",
+                },
+              ],
+            },
+          },
+        ),
+      ]),
+    ],
+    settings: { editToolPartsExpanded: true },
+  })
+
+  await expect(page.locator(`[data-timeline-part-id="${id}"] [data-component="apply-patch-file-diff"]`)).toBeVisible()
+})

packages/app/e2e/regression/session-timeline-file-state.spec.ts

@@ -0,0 +1,94 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("updates edit diagnostics without resetting manual collapse state", async ({ page }) => {
+  const editID = "prt_diagnostics_edit"
+  const base = editPart(editID, [])
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([base])],
+    settings: { editToolPartsExpanded: true },
+  })
+  const trigger = page.locator(`[data-timeline-part-id="${editID}"] [data-slot="collapsible-trigger"]`).first()
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+  await timeline.send(
+    partUpdated(editPart(editID, [diagnostic("First failure", 2), diagnostic("Second failure", 4)])),
+    300,
+  )
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+  await timeline.send(partUpdated(editPart(editID, [])), 300)
+  await expect(trigger).toHaveAttribute("aria-expanded", "false")
+})
+
+test("preserves nested patch file state through outer collapse and reopen", async ({ page }) => {
+  const patchID = "prt_nested_patch"
+  const files = [patchFile("src/a.ts", "update"), patchFile("src/b.ts", "add"), patchFile("src/old.ts", "delete")]
+  await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(
+          patchID,
+          "apply_patch",
+          "completed",
+          { files: files.map((file) => file.filePath) },
+          { metadata: { files } },
+        ),
+      ]),
+    ],
+    settings: { editToolPartsExpanded: true },
+  })
+  const wrapper = page.locator(`[data-timeline-part-id="${patchID}"]`)
+  const outer = wrapper.locator('[data-slot="collapsible-trigger"]').first()
+  const deleted = wrapper.locator('[data-scope="apply-patch"] [data-type="delete"]')
+  await deleted.getByRole("button").click()
+  await expect(deleted.getByRole("button")).toHaveAttribute("aria-expanded", "true")
+  await outer.click()
+  await expect(outer).toHaveAttribute("aria-expanded", "false")
+  await outer.click()
+  await expect(outer).toHaveAttribute("aria-expanded", "true")
+  await expect(deleted.getByRole("button")).toHaveAttribute("aria-expanded", "true")
+})
+
+function patchFile(filePath: string, type: "add" | "update" | "delete") {
+  return {
+    filePath,
+    relativePath: filePath,
+    type,
+    additions: type === "delete" ? 0 : 4,
+    deletions: type === "add" ? 0 : 3,
+    before: type === "add" ? undefined : source(false),
+    after: type === "delete" ? undefined : source(true),
+  }
+}
+
+function editPart(id: string, diagnostics: Record<string, unknown>[]) {
+  return toolPart(
+    id,
+    "edit",
+    "completed",
+    { filePath: "src/edit.ts" },
+    {
+      metadata: {
+        filediff: { file: "src/edit.ts", additions: 1, deletions: 1, before: source(false), after: source(true) },
+        diagnostics,
+      },
+    },
+  )
+}
+
+function diagnostic(message: string, line: number) {
+  return { message, severity: 1, range: { start: { line, character: 0 }, end: { line, character: 2 } } }
+}
+
+function source(changed: boolean) {
+  return Array.from({ length: 12 }, (_, index) => `export const value${index} = ${changed ? index + 1 : index}\n`).join(
+    "",
+  )
+}

packages/app/e2e/regression/session-timeline-history-root.spec.ts

@@ -0,0 +1,220 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { expect, test, type Page } from "@playwright/test"
+import {
+  assistantMessage,
+  directory,
+  messageUpdated,
+  project,
+  session,
+  sessionID,
+  status,
+  textPart,
+  title,
+  userID,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { installSseTransport } from "../utils/sse-transport"
+import { expectSessionTitle } from "../utils/waits"
+
+const assistants = Array.from({ length: 14 }, (_, index) =>
+  assistantMessage([textPart(`prt_history_root_${index}`, `Assistant response ${index}`)], {
+    id: `msg_${String(index + 1001).padStart(4, "0")}_history_root_assistant`,
+    parentID: userID,
+    created: 1700000001000 + index * 1_000,
+    completed: index < 13,
+  }),
+)
+const messages = [userMessage(), ...assistants]
+const lastAssistant = assistants.at(-1)!
+const lastPartID = assistants.at(-1)!.parts[0]!.id
+const userPartID = `prt_${userID}_text`
+const completed = {
+  ...lastAssistant.info,
+  time: { ...lastAssistant.info.time, completed: lastAssistant.info.time.created + 15_000 },
+}
+const scenarios = [
+  { name: "completion", info: completed, idleFirst: false, interrupted: false },
+  {
+    name: "interruption",
+    info: { ...completed, error: { name: "MessageAbortedError", data: { message: "Stopped" } } },
+    idleFirst: true,
+    interrupted: true,
+  },
+] as const
+
+test.use({ viewport: { width: 646, height: 1385 } })
+
+for (const scenario of scenarios) {
+  test(`keeps the latest user turn visible through ${scenario.name}`, async ({ page }) => {
+    const requests: { before?: string; phase: "start" | "end" }[] = []
+    const pages: { before?: string; limit: number }[] = []
+    const roots: { sessionID: string; messageID: string }[] = []
+    const sequence: string[] = []
+    const history = Promise.withResolvers<void>()
+    const transport = await installSseTransport<{ directory: string; payload: Record<string, unknown> }>(page, {
+      server: `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`,
+      retry: 20,
+    })
+    await mockOpenCodeServer(page, {
+      directory,
+      project: project(),
+      provider: {
+        all: [
+          {
+            id: "opencode",
+            name: "OpenCode",
+            models: {
+              "claude-opus-4-6": {
+                id: "claude-opus-4-6",
+                name: "Claude Opus 4.6",
+                limit: { context: 200_000 },
+              },
+            },
+          },
+        ],
+        connected: ["opencode"],
+        default: { providerID: "opencode", modelID: "claude-opus-4-6" },
+      },
+      sessions: [session()],
+      sessionStatus: { [sessionID]: { type: "busy" } },
+      beforeMessagesResponse: (request) => (request.before ? history.promise : Promise.resolve()),
+      onMessages: (request) => {
+        requests.push(request)
+        sequence.push(`messages:${request.phase}:${request.before ?? "latest"}`)
+      },
+      onMessage: (request) => {
+        roots.push(request)
+        sequence.push(`message:${request.messageID}`)
+      },
+      message: (requestedSessionID, messageID) => {
+        if (requestedSessionID !== sessionID) return
+        return messages.find((item) => item.info.id === messageID)
+      },
+      pageMessages: (_, limit, before) => {
+        pages.push({ before, limit })
+        const end = before ? messages.findIndex((message) => message.info.id === before) : messages.length
+        const start = Math.max(0, end - limit)
+        return {
+          items: messages.slice(start, end),
+          cursor: start > 0 ? messages[start]!.info.id : undefined,
+        }
+      },
+    })
+    await page.addInitScript(
+      ({ userPartID, lastPartID }) => {
+        const state = { armed: false, hidden: false, samples: 0, stop: false }
+        ;(window as Window & { __historyRootProbe?: typeof state }).__historyRootProbe = state
+        const sample = () => {
+          if (state.armed) {
+            const virtual = document.querySelector<HTMLElement>("[data-timeline-virtual-content]")
+            const viewport = virtual?.closest<HTMLElement>(".scroll-view__viewport")
+            const view = viewport?.getBoundingClientRect()
+            const visible = (partID: string) => {
+              const part = viewport?.querySelector<HTMLElement>(`[data-timeline-part-id="${partID}"]`)
+              const rect = part?.getBoundingClientRect()
+              return (
+                !!rect &&
+                !!view &&
+                rect.width > 0 &&
+                rect.height > 0 &&
+                rect.bottom > view.top &&
+                rect.top < view.bottom
+              )
+            }
+            if (!virtual || !visible(userPartID) || !visible(lastPartID)) state.hidden = true
+            state.samples++
+          }
+          if (!state.stop) requestAnimationFrame(() => setTimeout(sample, 0))
+        }
+        requestAnimationFrame(() => setTimeout(sample, 0))
+      },
+      { userPartID, lastPartID },
+    )
+
+    await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+    await transport.waitForConnection()
+    await expectSessionTitle(page, title)
+    await expect(page.locator(`[data-timeline-part-id="${lastPartID}"]`)).toBeVisible()
+    await expect(page.locator(`[data-timeline-part-id="${userPartID}"]`)).toBeVisible()
+    await expect.poll(() => requests.filter((request) => request.phase === "start").length).toBe(2)
+    expect(requests.filter((request) => request.phase === "end")).toHaveLength(1)
+    expect(sequence.slice(0, 4)).toEqual([
+      "messages:start:latest",
+      "messages:end:latest",
+      `message:${userID}`,
+      `messages:start:${messages.at(-2)!.info.id}`,
+    ])
+    await page.evaluate(() => {
+      ;(
+        window as Window & {
+          __historyRootProbe?: { armed: boolean }
+        }
+      ).__historyRootProbe!.armed = true
+    })
+    await waitForProbeSamples(page, 0)
+    expect(await historyRootHidden(page)).toBe(false)
+    const beforeHistory = await probeSamples(page)
+    history.resolve()
+    await expect(page.locator('[data-timeline-part-id^="prt_history_root_"]')).toHaveCount(14)
+    await expect(page.getByRole("button", { name: "Stop" })).toBeVisible()
+    await waitForProbeSamples(page, beforeHistory)
+    expect(pages[0]).toEqual({ before: undefined, limit: 2 })
+    expect(roots).toEqual([{ sessionID, messageID: userID }])
+
+    const message = messageUpdated(scenario.info)
+    const idle = status("idle")
+    for (const event of scenario.idleFirst ? [idle, message] : [message, idle]) {
+      const beforeEvent = await probeSamples(page)
+      await transport.send(event)
+      if (event === idle) await expect(page.getByRole("button", { name: "Stop" })).toHaveCount(0)
+      if (event === message && scenario.interrupted)
+        await expect(page.getByText("Interrupted", { exact: true })).toBeVisible()
+      await waitForProbeSamples(page, beforeEvent)
+      const current = await timelineState(page)
+      expect(current, JSON.stringify(current)).toMatchObject({ virtual: true })
+      expect(current.rows, JSON.stringify(current)).toBeGreaterThan(0)
+    }
+
+    expect(requests[0]).toEqual({ before: undefined, phase: "start", sessionID })
+    expect(requests[1]).toEqual({ before: undefined, phase: "end", sessionID })
+    await expect(page.getByRole("button", { name: "Stop" })).toHaveCount(0)
+    await expect(page.locator('[data-timeline-row="bottom-spacer"]')).toBeVisible()
+    if (scenario.interrupted) await expect(page.getByText("Interrupted", { exact: true })).toBeVisible()
+    expect(
+      await page.evaluate(() => {
+        const state = (window as Window & { __historyRootProbe?: { hidden: boolean; stop: boolean } })
+          .__historyRootProbe!
+        state.stop = true
+        return state.hidden
+      }),
+    ).toBe(false)
+  })
+}
+
+function timelineState(page: Page) {
+  return page.evaluate(() => ({
+    virtual: !!document.querySelector("[data-timeline-virtual-content]"),
+    rows: document.querySelectorAll("[data-timeline-key]").length,
+  }))
+}
+
+function probeSamples(page: Page) {
+  return page.evaluate(
+    () => (window as Window & { __historyRootProbe?: { samples: number } }).__historyRootProbe!.samples,
+  )
+}
+
+async function waitForProbeSamples(page: Page, after: number) {
+  await page.waitForFunction(
+    (after) =>
+      (window as Window & { __historyRootProbe?: { samples: number } }).__historyRootProbe!.samples >= after + 3,
+    after,
+  )
+}
+
+function historyRootHidden(page: Page) {
+  return page.evaluate(
+    () => (window as Window & { __historyRootProbe?: { hidden: boolean } }).__historyRootProbe!.hidden,
+  )
+}

packages/app/e2e/regression/session-timeline-lifecycle-state.spec.ts

@@ -0,0 +1,94 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  completedAssistantInfo,
+  messageUpdated,
+  partUpdated,
+  reasoningPart,
+  setupTimeline,
+  shell,
+  status,
+  textPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+for (const expanded of [false, true]) {
+  test(`preserves shell user intent from a ${expanded ? "expanded" : "collapsed"} default`, async ({ page }) => {
+    const id = `prt_shell_default_${expanded}`
+    const timeline = await setupTimeline(page, {
+      messages: [userMessage(), assistantMessage([shell(id, "completed", lines(3))])],
+      settings: { shellToolPartsExpanded: expanded },
+    })
+    const trigger = page.locator(`[data-timeline-part-id="${id}"] [data-slot="collapsible-trigger"]`)
+    await expect(trigger).toHaveAttribute("aria-expanded", String(expanded))
+    await trigger.click()
+    await expect(trigger).toHaveAttribute("aria-expanded", String(!expanded))
+
+    await timeline.send(partUpdated(shell(id, "completed", lines(6))), 180)
+    await timeline.send(partUpdated(textPart(`prt_sibling_${expanded}`, "Sibling content")), 180)
+    await timeline.send(status("busy"), 100)
+    await timeline.send(status("idle"), 250)
+    await expect(trigger).toHaveAttribute("aria-expanded", String(!expanded))
+  })
+}
+
+test("transitions thinking and hidden reasoning through busy to idle", async ({ page }) => {
+  const reasoningID = "prt_reasoning_hidden"
+  const assistant = assistantMessage([reasoningPart(reasoningID, "## Inspecting stability")], { completed: false })
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistant],
+    settings: { showReasoningSummaries: false },
+    cpuRate: 4,
+  })
+  await timeline.send(status("busy"), 150)
+
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+  await expect(page.getByText("Inspecting stability", { exact: true })).toBeVisible()
+  await expect(page.locator(`[data-timeline-part-id="${reasoningID}"]`)).toHaveCount(0)
+  await timeline.send(partUpdated(shell("prt_reasoning_shell", "running")), 160)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+  await timeline.send(partUpdated(shell("prt_reasoning_shell", "completed", "done")), 180)
+  await timeline.send(messageUpdated(completedAssistantInfo(assistant.info)), 100)
+  await timeline.send(status("idle"), 300)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await expect(page.locator(`[data-timeline-part-id="${reasoningID}"]`)).toHaveCount(0)
+})
+
+test("moves busy through retry and recovery to final idle content", async ({ page }) => {
+  const assistant = assistantMessage([], { completed: false })
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(undefined, {
+        summary: {
+          diffs: [
+            {
+              file: "src/retry.ts",
+              additions: 1,
+              deletions: 1,
+              patch: "@@ -1 +1 @@\n-export const retry = false\n+export const retry = true",
+            },
+          ],
+        },
+      }),
+      assistant,
+    ],
+  })
+  await timeline.send(status("busy"), 140)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-row="DiffSummary"]')).toHaveCount(0)
+  await timeline.send(status("retry"), 180)
+  await expect(page.locator('[data-timeline-row="Retry"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await timeline.send(status("busy", 2), 180)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toBeVisible()
+  await timeline.send(partUpdated(textPart("prt_recovered", "Recovered response")), 140)
+  await timeline.send(messageUpdated(completedAssistantInfo(assistant.info)), 100)
+  await timeline.send(status("idle"), 350)
+  await expect(page.locator('[data-timeline-row="Retry"]')).toHaveCount(0)
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await expect(page.locator('[data-timeline-row="DiffSummary"]')).toBeVisible()
+})
+
+function lines(count: number) {
+  return Array.from({ length: count }, (_, index) => `line ${index + 1}`).join("\n")
+}

packages/app/e2e/regression/session-timeline-locale-projection.spec.ts

@@ -0,0 +1,25 @@
+import { expect, test } from "@playwright/test"
+import { assistantMessage, setupTimeline, toolPart, userMessage } from "../performance/timeline-stability/fixture"
+
+for (const profile of [
+  { locale: "de", label: "Erkundet" },
+  { locale: "ar", label: "تم الاستكشاف" },
+] as const) {
+  test(`projects translated context status in ${profile.locale}`, async ({ page }) => {
+    const ids = [`prt_locale_${profile.locale}_01_read`, `prt_locale_${profile.locale}_02_glob`]
+    await setupTimeline(page, {
+      messages: [
+        userMessage(),
+        assistantMessage([
+          toolPart(ids[0]!, "read", "completed", { filePath: "src/a.ts" }),
+          toolPart(ids[1]!, "glob", "completed", { path: ".", pattern: "**/*.ts" }),
+        ]),
+      ],
+      locale: profile.locale,
+    })
+
+    const group = page.locator(`[data-timeline-part-ids="${ids.join(",")}"]`)
+    await expect(group.locator('[data-component="tool-status-title"]')).toHaveAttribute("aria-label", profile.label)
+    await expect(page.locator("html")).toHaveAttribute("lang", profile.locale)
+  })
+}

packages/app/e2e/regression/session-timeline-projection.spec.ts

@@ -0,0 +1,284 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  setupTimeline,
+  status,
+  toolPart,
+  userMessage,
+  userText,
+  type PartSeed,
+} from "../performance/timeline-stability/fixture"
+
+test.describe("session timeline projection", () => {
+  test("renders every admitted tool family and hides timeline-only exclusions", async ({ page }) => {
+    const parts = [
+      toolPart("prt_01_read", "read", "completed", { filePath: "src/a.ts" }),
+      toolPart("prt_02_glob", "glob", "completed", { path: ".", pattern: "**/*.ts" }),
+      toolPart("prt_03_grep", "grep", "completed", { path: ".", pattern: "value" }),
+      toolPart("prt_04_list", "list", "completed", { path: "src" }),
+      toolPart("prt_webfetch", "webfetch", "completed", { url: "https://example.com" }),
+      toolPart(
+        "prt_websearch",
+        "websearch",
+        "completed",
+        { query: "timeline stability" },
+        { output: "https://example.com/result" },
+      ),
+      toolPart("prt_task", "task", "completed", { description: "Inspect timeline", subagent_type: "explore" }),
+      toolPart(
+        "prt_bash",
+        "bash",
+        "completed",
+        { command: "printf stable" },
+        { output: "stable", title: "printf stable" },
+      ),
+      editPart("prt_edit"),
+      toolPart("prt_write", "write", "completed", { filePath: "src/new.ts", content: "export const stable = true\n" }),
+      patchPart("prt_patch"),
+      toolPart("prt_todo", "todowrite", "completed", { todos: [{ content: "Hidden", status: "pending" }] }),
+      toolPart(
+        "prt_question",
+        "question",
+        "completed",
+        { questions: [{ question: "Keep stable?", header: "Stability", options: [] }] },
+        { metadata: { answers: [["Yes"]] } },
+      ),
+      toolPart("prt_skill", "skill", "completed", { name: "stability" }),
+      toolPart("prt_custom", "custom_mcp_tool", "completed", { target: "timeline", count: 2 }),
+    ]
+    await setupTimeline(page, { messages: [userMessage(), assistantMessage(parts)] })
+
+    await expect(
+      page.locator('[data-timeline-part-ids="prt_01_read,prt_02_glob,prt_03_grep,prt_04_list"]'),
+    ).toBeVisible()
+    for (const id of [
+      "prt_webfetch",
+      "prt_websearch",
+      "prt_task",
+      "prt_bash",
+      "prt_edit",
+      "prt_write",
+      "prt_patch",
+      "prt_question",
+      "prt_skill",
+      "prt_custom",
+    ]) {
+      await expect(page.locator(`[data-timeline-part-id="${id}"]`).first(), id).toBeVisible()
+    }
+    await expect(page.locator('[data-timeline-part-id="prt_todo"]')).toHaveCount(0)
+  })
+
+  test("projects gaps, dividers, assistant parts, and errors together", async ({ page }) => {
+    const firstUser = userMessage(
+      [
+        userText("The user made the following comment regarding lines 4 through 8 of src/a.ts: Keep this stable", {
+          id: "prt_comment",
+          synthetic: true,
+          metadata: {
+            opencodeComment: {
+              path: "src/a.ts",
+              selection: { startLine: 4, startChar: 0, endLine: 8, endChar: 0 },
+              comment: "Keep this stable",
+            },
+          },
+        }),
+        userText("Continue after the comment", { id: "prt_visible_user" }),
+      ],
+      { summary: { diffs: Array.from({ length: 11 }, (_, index) => summaryDiff(index)) } },
+    )
+    const aborted = assistantMessage(
+      [
+        { id: "prt_before_abort", type: "text", text: "Before interruption" },
+        { id: "prt_compaction", type: "compaction", auto: true },
+      ],
+      {
+        id: "msg_1001_assistant_aborted",
+        error: { name: "MessageAbortedError", data: { message: "Stopped" } },
+      },
+    )
+    const failed = assistantMessage([{ id: "prt_after_abort", type: "text", text: "After interruption" }], {
+      id: "msg_1002_assistant_failed",
+      error: {
+        name: "APIError",
+        data: {
+          message: JSON.stringify({ error: { type: "provider_error", message: "Visible provider failure" } }),
+          isRetryable: false,
+        },
+      },
+      created: 1700000003000,
+    })
+    const nextUser = userMessage([userText("Second turn", { id: "prt_second_user" })], {
+      id: "msg_2000_second_user",
+      created: 1700000005000,
+    })
+    const nextAssistant = assistantMessage([{ id: "prt_second_text", type: "text", text: "Second response" }], {
+      id: "msg_2001_second_assistant",
+      parentID: "msg_2000_second_user",
+      created: 1700000006000,
+    })
+    const timeline = await setupTimeline(page, { messages: [firstUser, aborted, failed, nextUser, nextAssistant] })
+    await timeline.send(status("idle"), 100)
+    const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+    await scroller.evaluate((element) => (element.scrollTop = 0))
+
+    await expect(page.locator('[data-timeline-row="TurnDivider"]')).toHaveCount(1)
+    await expect(page.getByText("Session compacted", { exact: true })).toBeVisible()
+    await expect(page.getByText("Visible provider failure")).toBeVisible()
+    await scroller.evaluate((element) => (element.scrollTop = element.scrollHeight))
+    await expect(page.locator('[data-timeline-row="TurnGap"]')).toBeVisible()
+  })
+
+  test("renders comment strips and historical diff summary overflow", async ({ page }) => {
+    const user = userMessage(
+      [
+        userText("The user made the following comment regarding lines 4 through 8 of src/a.ts: Keep this stable", {
+          id: "prt_comment_only",
+          synthetic: true,
+          metadata: {
+            opencodeComment: {
+              path: "src/a.ts",
+              selection: { startLine: 4, startChar: 0, endLine: 8, endChar: 0 },
+              comment: "Keep this stable",
+            },
+          },
+        }),
+        userText("Continue after the comment", { id: "prt_comment_visible" }),
+      ],
+      { summary: { diffs: Array.from({ length: 11 }, (_, index) => summaryDiff(index)) } },
+    )
+    const nextUser = userMessage(undefined, { id: "msg_2000_diff_next_user", created: 1700000010000 })
+    const nextAssistant = assistantMessage([], {
+      id: "msg_2001_diff_next_assistant",
+      parentID: "msg_2000_diff_next_user",
+      created: 1700000011000,
+    })
+    await setupTimeline(page, { messages: [user, assistantMessage(), nextUser, nextAssistant] })
+    const scroller = page.locator(".scroll-view__viewport", { has: page.locator("[data-timeline-row]") })
+    await scroller.evaluate((element) => (element.scrollTop = 0))
+
+    await expect(page.locator('[data-timeline-row="CommentStrip"]')).toBeVisible()
+    await expect(page.getByText("Keep this stable", { exact: true })).toBeVisible()
+    await expect(page.locator('[data-timeline-row="DiffSummary"]')).toBeVisible()
+    await expect(page.getByText(/show all/i)).toBeVisible()
+  })
+
+  test("renders interruption independently when the turn is not compacted", async ({ page }) => {
+    const user = userMessage()
+    const before = assistantMessage([{ id: "prt_before", type: "text", text: "Before" }], {
+      id: "msg_1001_before",
+      error: { name: "MessageAbortedError", data: { message: "Stopped" } },
+    })
+    const after = assistantMessage([{ id: "prt_after", type: "text", text: "After" }], {
+      id: "msg_1002_after",
+      created: 1700000003000,
+    })
+    await setupTimeline(page, { messages: [user, before, after] })
+
+    await expect(page.getByText("Interrupted", { exact: true })).toBeVisible()
+    const rows = await page
+      .locator('[data-timeline-row="AssistantPart"], [data-timeline-row="TurnDivider"]')
+      .evaluateAll((elements) => elements.map((element) => element.getAttribute("data-timeline-row")))
+    expect(rows).toEqual(["AssistantPart", "TurnDivider", "AssistantPart"])
+  })
+
+  test("renders user image, file attachment, file reference, and agent reference", async ({ page }) => {
+    const text = "Use @explore with @src/a.ts and inspect the attachments"
+    const parts: PartSeed<"user">[] = [
+      userText(text, { id: "prt_user_rich" }),
+      {
+        id: "prt_user_image",
+        type: "file",
+        mime: "image/png",
+        filename: "pixel.png",
+        url: "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==",
+      },
+      {
+        id: "prt_user_attachment",
+        type: "file",
+        mime: "application/json",
+        filename: "tsconfig.json",
+        url: "data:application/json;base64,e30=",
+      },
+      {
+        id: "prt_user_reference",
+        type: "file",
+        mime: "text/plain",
+        filename: "a.ts",
+        url: "src/a.ts",
+        source: { type: "file", path: "src/a.ts", text: { value: "@src/a.ts", start: 18, end: 27 } },
+      },
+      {
+        id: "prt_user_agent",
+        type: "agent",
+        name: "explore",
+        source: { value: "@explore", start: 4, end: 12 },
+      },
+    ]
+    await setupTimeline(page, { messages: [userMessage(parts), assistantMessage()] })
+
+    await expect(page.getByAltText("pixel.png")).toBeVisible()
+    await expect(page.getByText("tsconfig.json")).toBeVisible()
+    await expect(page.getByText("@src/a.ts", { exact: true })).toBeVisible()
+    await expect(page.getByText("@explore", { exact: true })).toBeVisible()
+  })
+})
+
+function editPart(id: string) {
+  return toolPart(
+    id,
+    "edit",
+    "completed",
+    { filePath: "src/a.ts" },
+    {
+      metadata: {
+        filediff: {
+          file: "src/a.ts",
+          additions: 1,
+          deletions: 1,
+          before: "export const value = 1\n",
+          after: "export const value = 2\n",
+        },
+      },
+    },
+  )
+}
+
+function patchPart(id: string) {
+  return toolPart(
+    id,
+    "apply_patch",
+    "completed",
+    { files: ["src/a.ts", "src/b.ts"] },
+    {
+      metadata: {
+        files: [
+          patchFile("src/a.ts", "update"),
+          patchFile("src/b.ts", "add"),
+          patchFile("src/old.ts", "delete"),
+          { ...patchFile("src/moved.ts", "move"), move: "src/new-place.ts" },
+        ],
+      },
+    },
+  )
+}
+
+function patchFile(filePath: string, type: "add" | "update" | "delete" | "move") {
+  return {
+    filePath,
+    relativePath: filePath,
+    type,
+    additions: type === "delete" ? 0 : 1,
+    deletions: type === "add" ? 0 : 1,
+    before: type === "add" ? undefined : "export const before = true\n",
+    after: type === "delete" ? undefined : "export const after = true\n",
+  }
+}
+
+function summaryDiff(index: number) {
+  return {
+    file: `src/diff-${index}.ts`,
+    additions: 1,
+    deletions: 1,
+    patch: `@@ -1 +1 @@\n-export const value = ${index}\n+export const value = ${index + 1}`,
+  }
+}

packages/app/e2e/regression/session-timeline-reasoning-projection.spec.ts

@@ -0,0 +1,93 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  reasoningPart,
+  setupTimeline,
+  status,
+  textPart,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+const profiles = [
+  { name: "summaries off no reasoning", summaries: false, reasoning: "", other: false, thinking: true, body: false },
+  {
+    name: "summaries off reasoning heading",
+    summaries: false,
+    reasoning: "## Inspecting stability",
+    other: false,
+    thinking: true,
+    body: false,
+  },
+  {
+    name: "summaries off with visible tool",
+    summaries: false,
+    reasoning: "## Inspecting stability",
+    other: true,
+    thinking: true,
+    body: false,
+  },
+  { name: "summaries on no content", summaries: true, reasoning: "", other: false, thinking: true, body: false },
+  {
+    name: "summaries on blank reasoning",
+    summaries: true,
+    reasoning: "   ",
+    other: false,
+    thinking: true,
+    body: false,
+  },
+  {
+    name: "summaries on visible reasoning",
+    summaries: true,
+    reasoning: "## Inspecting stability",
+    other: false,
+    thinking: false,
+    body: true,
+  },
+  {
+    name: "summaries on visible tool no reasoning",
+    summaries: true,
+    reasoning: "",
+    other: true,
+    thinking: false,
+    body: false,
+  },
+] as const
+
+for (const profile of profiles) {
+  test(`projects busy reasoning profile ${profile.name}`, async ({ page }) => {
+    const reasoningID = `prt_reasoning_matrix_${profiles.indexOf(profile)}`
+    const parts = [
+      ...(profile.reasoning ? [reasoningPart(reasoningID, profile.reasoning)] : []),
+      ...(profile.other
+        ? [toolPart(`prt_reasoning_tool_${profiles.indexOf(profile)}`, "skill", "running", { name: "inspect" })]
+        : []),
+    ]
+    const timeline = await setupTimeline(page, {
+      messages: [userMessage(), assistantMessage(parts, { completed: false })],
+      settings: { showReasoningSummaries: profile.summaries },
+    })
+    await timeline.send(status("busy"), 150)
+
+    await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(profile.thinking ? 1 : 0)
+    await expect(page.locator(`[data-timeline-part-id="${reasoningID}"]`)).toHaveCount(profile.body ? 1 : 0)
+    if (!profile.summaries && profile.reasoning.trim()) {
+      await expect(page.getByText("Inspecting stability", { exact: true })).toBeVisible()
+    }
+  })
+}
+
+test("does not infer reasoning visibility from provider identity", async ({ page }) => {
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([textPart("prt_provider_text", "No reasoning payload")], { completed: false }),
+    ],
+    settings: { showReasoningSummaries: true },
+  })
+  await timeline.send(status("busy"), 150)
+
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await expect(page.locator('[data-timeline-part-id*="reasoning"]')).toHaveCount(0)
+  await expect(page.locator('[data-timeline-part-id="prt_provider_text"]')).toBeVisible()
+})

packages/app/e2e/regression/session-timeline-reducer-projection.spec.ts

@@ -0,0 +1,43 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  completedAssistantInfo,
+  messageUpdated,
+  partUpdated,
+  setupTimeline,
+  shell,
+  status,
+  textPart,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("groups singleton and separated context operations at correct boundaries", async ({ page }) => {
+  const parts = [
+    toolPart("prt_boundary_01_read", "read", "completed", { filePath: "src/a.ts" }),
+    textPart("prt_boundary_02_text", "Boundary text"),
+    toolPart("prt_boundary_03_glob", "glob", "completed", { path: ".", pattern: "**/*.ts" }),
+    toolPart("prt_boundary_04_grep", "grep", "completed", { path: ".", pattern: "stable" }),
+    shell("prt_boundary_05_shell", "completed", "done"),
+    toolPart("prt_boundary_06_list", "list", "completed", { path: "src" }),
+  ]
+  await setupTimeline(page, { messages: [userMessage(), assistantMessage(parts)] })
+
+  await expect(page.locator('[data-timeline-part-ids="prt_boundary_01_read"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-part-ids="prt_boundary_03_glob,prt_boundary_04_grep"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-part-ids="prt_boundary_06_list"]')).toBeVisible()
+  await expect(page.locator('[data-timeline-row="AssistantPart"]')).toHaveCount(5)
+})
+
+test("reducer-hardening: converges when idle arrives before final part and message completion", async ({ page }) => {
+  const textID = "prt_event_order_text"
+  const assistant = assistantMessage([textPart(textID, "Partial")], { completed: false })
+  const timeline = await setupTimeline(page, { messages: [userMessage(), assistant] })
+  await timeline.send(status("busy"), 100)
+  await timeline.send(status("idle"), 100)
+  await timeline.send(partUpdated(textPart(textID, "Final after early idle")), 120)
+  await timeline.send(messageUpdated(completedAssistantInfo(assistant.info)), 250)
+
+  await expect(page.locator('[data-timeline-row="Thinking"]')).toHaveCount(0)
+  await expect(page.locator(`[data-timeline-part-id="${textID}"]`)).toContainText("Final after early idle")
+})

packages/app/e2e/regression/session-timeline-tool-projection.spec.ts

@@ -0,0 +1,99 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("renders every tool error outcome without leaking hidden tools", async ({ page }) => {
+  const ordinary = ["bash", "edit", "write", "apply_patch", "webfetch", "websearch", "task", "skill", "mcp_probe"]
+  const parts = ordinary.map((tool, index) =>
+    toolPart(`prt_error_${index}`, tool, "error", errorInput(tool), { error: `${tool} failed visibly` }),
+  )
+  parts.push(
+    toolPart("prt_question_dismissed", "question", "error", questionInput(), {
+      error: "The user dismissed this question",
+    }),
+    toolPart("prt_question_error", "question", "error", questionInput(), { error: "Question transport failed" }),
+    toolPart("prt_todo_error", "todowrite", "error", { todos: [] }, { error: "Hidden todo failure" }),
+  )
+  await setupTimeline(page, { messages: [userMessage(), assistantMessage(parts)] })
+
+  await expect(page.locator('[data-kind="tool-error-card"]')).toHaveCount(ordinary.length + 1)
+  await expect(page.getByText(/dismissed/i)).toBeVisible()
+  await expect(page.locator('[data-timeline-part-id="prt_todo_error"]')).toHaveCount(0)
+  for (let index = 0; index < ordinary.length; index++) {
+    await expect(page.locator(`[data-timeline-part-id="prt_error_${index}"]`)).toBeVisible()
+  }
+})
+
+test("transitions shell and question through running error outcomes", async ({ page }) => {
+  const shellID = "prt_transition_error_shell"
+  const questionID = "prt_transition_error_question"
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage(
+        [
+          toolPart(shellID, "bash", "pending", { command: "exit 1" }),
+          toolPart(questionID, "question", "pending", questionInput()),
+        ],
+        { completed: false },
+      ),
+    ],
+  })
+  await timeline.waitForPart(shellID)
+  await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toHaveCount(0)
+  await timeline.send(partUpdated(toolPart(shellID, "bash", "running", { command: "exit 1" })), 120)
+  await timeline.send(partUpdated(toolPart(questionID, "question", "running", questionInput())), 180)
+  await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toHaveCount(0)
+  await timeline.send(
+    partUpdated(toolPart(shellID, "bash", "error", { command: "exit 1" }, { error: "Command exited 1" })),
+    180,
+  )
+  await timeline.send(
+    partUpdated(
+      toolPart(questionID, "question", "error", questionInput(), { error: "The user dismissed this question" }),
+    ),
+    250,
+  )
+
+  await expect(page.locator(`[data-timeline-part-id="${shellID}"] [data-kind="tool-error-card"]`)).toBeVisible()
+  await expect(page.locator(`[data-timeline-part-id="${questionID}"]`)).toContainText(/dismissed/i)
+})
+
+test("labels all web search provider variants", async ({ page }) => {
+  const parts = [
+    toolPart(
+      "prt_search_parallel",
+      "websearch",
+      "completed",
+      { query: "parallel" },
+      { metadata: { provider: "parallel" } },
+    ),
+    toolPart("prt_search_exa", "websearch", "completed", { query: "exa" }, { metadata: { provider: "exa" } }),
+    toolPart("prt_search_generic", "websearch", "completed", { query: "generic" }),
+  ]
+  await setupTimeline(page, { messages: [userMessage(), assistantMessage(parts)] })
+
+  await expect(page.getByRole("button", { name: /Parallel Web Search/ })).toBeVisible()
+  await expect(page.getByRole("button", { name: /Exa Web Search/ })).toBeVisible()
+  await expect(page.getByRole("button", { name: /^Web Search/ })).toBeVisible()
+})
+
+function questionInput() {
+  return { questions: [{ header: "Stability", question: "Keep it stable?", options: [] }] }
+}
+
+function errorInput(tool: string) {
+  if (tool === "bash") return { command: "exit 1" }
+  if (["edit", "write"].includes(tool)) return { filePath: "src/error.ts", content: "" }
+  if (tool === "apply_patch") return { files: ["src/error.ts"] }
+  if (tool === "webfetch") return { url: "https://example.com" }
+  if (tool === "websearch") return { query: "failure" }
+  if (tool === "task") return { description: "Fail task", subagent_type: "explore" }
+  if (tool === "skill") return { name: "failure" }
+  return { target: "failure" }
+}

packages/app/e2e/regression/session-timeline-tool-state.spec.ts

@@ -0,0 +1,77 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  toolPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("updates expanded web search links without resetting expansion", async ({ page }) => {
+  const searchID = "prt_websearch_mutation"
+  const input = { query: "timeline stability" }
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([toolPart(searchID, "websearch", "completed", input, { output: "https://example.com/one" })]),
+    ],
+  })
+  const wrapper = page.locator(`[data-timeline-part-id="${searchID}"]`)
+  const trigger = wrapper.locator('[data-slot="collapsible-trigger"]')
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await timeline.send(
+    partUpdated(
+      toolPart(searchID, "websearch", "completed", input, {
+        output: "https://example.com/one\nhttps://example.com/two",
+      }),
+    ),
+    300,
+  )
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await expect(wrapper.locator('a[href="https://example.com/two"]')).toBeVisible()
+})
+
+test("preserves an expanded tool error card across duplicate delivery", async ({ page }) => {
+  const toolID = "prt_duplicate_error"
+  const failed = toolPart(toolID, "bash", "error", { command: "exit 1" }, { error: "Command failed visibly" })
+  const timeline = await setupTimeline(page, { messages: [userMessage(), assistantMessage([failed])] })
+  const wrapper = page.locator(`[data-timeline-part-id="${toolID}"]`)
+  const trigger = wrapper.locator('[data-slot="collapsible-trigger"]')
+  await trigger.click()
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await timeline.send(partUpdated(failed), 150)
+  await timeline.send(partUpdated(failed), 250)
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await expect(wrapper).toContainText("Command failed visibly")
+})
+
+test("renders multiple question answers and preserves open state on answer updates", async ({ page }) => {
+  const questionID = "prt_multi_question"
+  const input = {
+    questions: [
+      { header: "First", question: "First choice?", options: [] },
+      { header: "Second", question: "Second choice?", options: [], multiple: true },
+    ],
+  }
+  const timeline = await setupTimeline(page, {
+    messages: [
+      userMessage(),
+      assistantMessage([
+        toolPart(questionID, "question", "completed", input, { metadata: { answers: [["A"], ["B", "C"]] } }),
+      ]),
+    ],
+  })
+  const wrapper = page.locator(`[data-timeline-part-id="${questionID}"]`)
+  const trigger = wrapper.locator('[data-slot="collapsible-trigger"]')
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await timeline.send(
+    partUpdated(
+      toolPart(questionID, "question", "completed", input, { metadata: { answers: [["Updated"], ["B", "C"]] } }),
+    ),
+    300,
+  )
+  await expect(trigger).toHaveAttribute("aria-expanded", "true")
+  await expect(wrapper).toContainText("Updated")
+  await expect(wrapper).toContainText("B, C")
+})

packages/app/e2e/regression/session-timeline-transport.spec.ts

@@ -0,0 +1,116 @@
+import { expect, test } from "@playwright/test"
+import {
+  assistantMessage,
+  partUpdated,
+  setupTimeline,
+  status,
+  textPart,
+  userMessage,
+} from "../performance/timeline-stability/fixture"
+
+test("keeps one connection open while delivering multiple events", async ({ page }) => {
+  const timeline = await setupTimeline(page)
+
+  const first = await timeline.transport.send(partUpdated(textPart("prt_transport_first", "first event")))
+  const second = await timeline.transport.send(partUpdated(textPart("prt_transport_second", "second event")))
+
+  await timeline.waitForPart("prt_transport_first")
+  await timeline.waitForPart("prt_transport_second")
+  expect(first.connectionID).toBe(second.connectionID)
+  expect(await timeline.transport.connections()).toHaveLength(1)
+  expect(await timeline.transport.acknowledgements()).toHaveLength(2)
+})
+
+test("delivers a burst from one stream chunk", async ({ page }) => {
+  const timeline = await setupTimeline(page)
+  const acknowledgements = await timeline.transport.burst([
+    partUpdated(textPart("prt_transport_burst_a", "burst a")),
+    partUpdated(textPart("prt_transport_burst_b", "burst b")),
+  ])
+
+  await timeline.waitForPart("prt_transport_burst_a")
+  await timeline.waitForPart("prt_transport_burst_b")
+  expect(acknowledgements.map((item) => item.chunkCount)).toEqual([1, 1])
+  expect(new Set(acknowledgements.map((item) => item.deliveryID)).size).toBe(2)
+})
+
+test("parses split JSON and a split multibyte code point", async ({ page }) => {
+  const timeline = await setupTimeline(page)
+  const payload = partUpdated(textPart("prt_transport_split", "split snowman \u2603\u2603\u2603"))
+  const encoded = new TextEncoder().encode(`data: ${JSON.stringify(payload)}\n\n`)
+  const snowman = new TextEncoder().encode("\u2603")[0]!
+  const multibyte = encoded.indexOf(snowman)
+
+  const acknowledgement = await timeline.transport.split(payload, [9, multibyte + 1, multibyte + 2])
+
+  await timeline.waitForPart("prt_transport_split")
+  await expect(page.locator('[data-timeline-part-id="prt_transport_split"]')).toContainText(
+    "split snowman \u2603\u2603\u2603",
+  )
+  expect(acknowledgement.chunkCount).toBe(4)
+})
+
+test("delivers server heartbeat without mutating the timeline", async ({ page }) => {
+  const timeline = await setupTimeline(page, {
+    messages: [userMessage(), assistantMessage([textPart("prt_transport_steady", "steady")])],
+  })
+  const before = await page.locator("[data-timeline-row]").allTextContents()
+
+  await timeline.transport.heartbeat()
+  await timeline.settle()
+
+  expect(await page.locator("[data-timeline-row]").allTextContents()).toEqual(before)
+  expect(await timeline.transport.connections()).toHaveLength(1)
+})
+
+test("reconnects after a clean close", async ({ page }) => {
+  const timeline = await setupTimeline(page, { eventRetry: 10 })
+  const first = await timeline.transport.waitForConnection()
+
+  await timeline.transport.close()
+  const second = await timeline.transport.waitForConnection({ after: first.id })
+  await timeline.transport.send(partUpdated(textPart("prt_transport_close", "after close")))
+
+  await timeline.waitForPart("prt_transport_close")
+  expect(second.id).toBeGreaterThan(first.id)
+  expect((await timeline.transport.connections())[0]?.endedBy).toBe("close")
+})
+
+test("reconnects after a stream error", async ({ page }) => {
+  const timeline = await setupTimeline(page, { eventRetry: 10 })
+  const first = await timeline.transport.waitForConnection()
+
+  await timeline.transport.error("contract failure")
+  const second = await timeline.transport.waitForConnection({ after: first.id })
+  await timeline.transport.send(status("busy"))
+
+  await expect.poll(async () => (await timeline.transport.connections()).length).toBe(2)
+  expect(second.id).toBeGreaterThan(first.id)
+  expect((await timeline.transport.connections())[0]?.endedBy).toBe("error")
+})
+
+test("records event IDs and reconnect Last-Event-ID headers", async ({ page }) => {
+  const timeline = await setupTimeline(page, { eventRetry: 10 })
+  const first = await timeline.transport.send(partUpdated(textPart("prt_transport_id", "event with id")), {
+    id: "timeline-event-7",
+  })
+  await timeline.waitForPart("prt_transport_id")
+
+  await timeline.transport.error("retry with event id")
+  const connection = await timeline.transport.waitForConnection({ after: first.connectionID })
+
+  expect(first.eventID).toBe("timeline-event-7")
+  expect(connection.headers["last-event-id"]).toBe("timeline-event-7")
+})
+
+test("passes through non-event fetches", async ({ page }) => {
+  const timeline = await setupTimeline(page)
+
+  const health = await page.evaluate(async () => {
+    const response = await fetch("/global/health")
+    return response.json()
+  })
+
+  expect(health).toEqual({ healthy: true })
+  expect(await timeline.transport.connections()).toHaveLength(1)
+})

packages/app/e2e/regression/session-todo-dock-navigation.spec.ts

@@ -145,7 +145,7 @@ async function configurePage(page: Page) {
         }),
       )
       localStorage.setItem(
-        "opencode.global.dat:tabs",
+        "opencode.window.browser.dat:tabs",
         JSON.stringify(sessionIDs.map((sessionId) => ({ type: "session", server, dirBase64, sessionId }))),
       )
     },

packages/app/e2e/regression/subagent-child-navigation.spec.ts

@@ -0,0 +1,200 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { expect, test, type Page } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/SubagentNavigation"
+const projectID = "proj_subagent_navigation"
+const parentID = "ses_subagent_parent"
+const childID = "ses_subagent_child"
+const parentTitle = "Parent session"
+const childTitle = "Subagent child session"
+// Child session pages derive their heading from the task part that spawned them.
+const taskDescription = "Inspect child navigation"
+
+type EventPayload = { directory: string; payload: Record<string, unknown> }
+
+test.use({ viewport: { width: 1440, height: 900 } })
+
+test("navigates to a subagent child session missing from the session list", async ({ page }) => {
+  await setup(page)
+  await openChildFromParent(page)
+
+  await expectSessionTitle(page, taskDescription)
+  await expect(page.getByRole("heading", { name: parentTitle })).toHaveCount(0)
+
+  const titlebarRight = page.locator("#opencode-titlebar-right")
+  await expect(titlebarRight.getByRole("button", { name: "Toggle review" })).toHaveCount(1)
+})
+
+test("shows the not found fallback when the viewed session is deleted", async ({ page }) => {
+  const events: EventPayload[] = []
+  await setup(page, () => events.splice(0, 1))
+  await openChildFromParent(page)
+  await expectSessionTitle(page, taskDescription)
+
+  events.push({
+    directory,
+    payload: { type: "session.deleted", properties: { info: childSession() } },
+  })
+
+  await expect(page.getByText("This session cannot be found")).toBeVisible()
+  await expect(page.getByRole("button", { name: "Close Tab" })).toBeVisible()
+  await expect(page.getByRole("heading", { name: taskDescription })).toHaveCount(0)
+})
+
+async function setup(page: Page, events?: () => EventPayload[]) {
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "subagent-navigation",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: {
+            "claude-opus-4-6": { id: "claude-opus-4-6", name: "Claude Opus 4.6", limit: { context: 200_000 } },
+          },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "claude-opus-4-6" },
+    },
+    sessions: [session(parentID, parentTitle, 1700000000000), childSession()],
+    pageMessages: (sessionID) => ({ items: sessionID === parentID ? parentMessages() : [] }),
+    events,
+    eventRetry: events ? 16 : undefined,
+  })
+  // The child session resolves via /session/:id but is absent from the /session list,
+  // matching a subagent session that has not been loaded into the list cache yet.
+  await page.route(
+    (url) => url.pathname === "/session" && url.port === (process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"),
+    (route) =>
+      route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        headers: { "access-control-allow-origin": "*" },
+        body: JSON.stringify([session(parentID, parentTitle, 1700000000000)]),
+      }),
+  )
+  await configurePage(page)
+}
+
+async function openChildFromParent(page: Page) {
+  await page.goto(sessionHref(parentID))
+  await expectSessionTitle(page, parentTitle)
+
+  const card = page.locator(`a[href="${sessionHref(childID)}"]`)
+  await expect(card).toBeVisible()
+  await card.click()
+
+  await expect(page).toHaveURL(new RegExp(`/server/.+/session/${childID}$`), { timeout: 15_000 })
+}
+
+function session(id: string, title: string, created: number, extra?: Record<string, unknown>) {
+  return {
+    id,
+    slug: id,
+    projectID,
+    directory,
+    title,
+    version: "dev",
+    time: { created, updated: created },
+    ...extra,
+  }
+}
+
+function childSession() {
+  return session(childID, childTitle, 1700000001000, { parentID })
+}
+
+function parentMessages() {
+  const userID = "msg_user_0001"
+  const assistantID = "msg_assistant_0001"
+  return [
+    {
+      info: {
+        id: userID,
+        sessionID: parentID,
+        role: "user",
+        time: { created: 1700000000000 },
+        agent: "build",
+        model: { providerID: "opencode", modelID: "claude-opus-4-6" },
+      },
+      parts: [
+        {
+          id: "prt_user_text_0001",
+          sessionID: parentID,
+          messageID: userID,
+          type: "text",
+          text: "Delegate work to a subagent",
+        },
+      ],
+    },
+    {
+      info: {
+        id: assistantID,
+        sessionID: parentID,
+        role: "assistant",
+        time: { created: 1700000001000, completed: 1700000002000 },
+        parentID: userID,
+        modelID: "claude-opus-4-6",
+        providerID: "opencode",
+        mode: "build",
+        agent: "build",
+        path: { cwd: directory, root: directory },
+        cost: 0.01,
+        tokens: { input: 100, output: 200, reasoning: 0, cache: { read: 0, write: 0 } },
+        finish: "stop",
+      },
+      parts: [
+        {
+          id: "prt_tool_task_0001",
+          sessionID: parentID,
+          messageID: assistantID,
+          type: "tool",
+          callID: "call_task_0001",
+          tool: "task",
+          state: {
+            status: "completed",
+            input: { description: taskDescription, subagent_type: "explore" },
+            output: "Subagent finished",
+            title: taskDescription,
+            metadata: { sessionId: childID },
+            time: { start: 1700000001000, end: 1700000002000 },
+          },
+        },
+      ],
+    },
+  ]
+}
+
+async function configurePage(page: Page) {
+  const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+  await page.addInitScript(
+    ({ directory, server, sessionId }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem(
+        "opencode.global.dat:server",
+        JSON.stringify({
+          projects: { local: [{ worktree: directory, expanded: true }] },
+          lastProject: { local: directory },
+        }),
+      )
+      localStorage.setItem("opencode.window.browser.dat:tabs", JSON.stringify([{ type: "session", server, sessionId }]))
+    },
+    { directory, server, sessionId: parentID },
+  )
+}
+
+function sessionHref(sessionID: string) {
+  const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+  return `/server/${base64Encode(server)}/session/${sessionID}`
+}

packages/app/e2e/regression/tab-navigate-mousedown.spec.ts

@@ -0,0 +1,108 @@
+import { expect, test, type Page, type Route } from "@playwright/test"
+import { base64Encode } from "@opencode-ai/core/util/encode"
+
+const server = "http://127.0.0.1:4096"
+const sessionA = session("ses_tab_a", "Tab A session")
+const sessionB = session("ses_tab_b", "Tab B session")
+
+test("pressing mouse down on a tab navigates before mouse up", async ({ page }) => {
+  await mockServer(page)
+  await page.addInitScript(
+    ({ server, sessionA, sessionB }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify([
+          { type: "session", server, sessionId: sessionA },
+          { type: "session", server, sessionId: sessionB },
+        ]),
+      )
+    },
+    { server, sessionA: sessionA.id, sessionB: sessionB.id },
+  )
+
+  const hrefA = `/server/${base64Encode(server)}/session/${sessionA.id}`
+  const hrefB = `/server/${base64Encode(server)}/session/${sessionB.id}`
+  await page.goto(hrefA)
+  await expect(page.getByText(sessionA.title).first()).toBeVisible()
+
+  const linkB = page.locator(`a[data-titlebar-tab-link][href="${hrefB}"]`)
+  await expect(linkB).toBeVisible()
+  const box = await linkB.boundingBox()
+  if (!box) throw new Error("tab link has no bounding box")
+  await page.mouse.move(box.x + box.width / 2, box.y + box.height / 2)
+  await page.mouse.down()
+
+  // Navigation must happen on mousedown, before the button is released.
+  await expect(page).toHaveURL(new RegExp(`${hrefB.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")}$`))
+  await page.mouse.up()
+  await expect(page).toHaveURL(new RegExp(`${hrefB.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")}$`))
+})
+
+function session(id: string, title: string) {
+  return {
+    id,
+    slug: id,
+    projectID: "project-tabs",
+    directory: "C:/tab-project",
+    title,
+    version: "dev",
+    time: { created: 1, updated: 1 },
+  }
+}
+
+async function mockServer(page: Page) {
+  const sessions = [sessionA, sessionB]
+  await page.route("**/*", async (route) => {
+    const url = new URL(route.request().url())
+    if (url.origin !== server) return route.fallback()
+    if (url.pathname === "/global/event" || url.pathname === "/event") return sse(route)
+    if (url.pathname === "/global/health") return json(route, { healthy: true })
+    if (url.pathname === "/session") return json(route, sessions)
+    const byId = sessions.find((item) => url.pathname === `/session/${item.id}`)
+    if (byId) return json(route, byId)
+    if (/^\/session\/[^/]+$/.test(url.pathname)) return json(route, { name: "NotFoundError" }, 404)
+    if (/^\/session\/[^/]+\/message$/.test(url.pathname)) return json(route, [])
+    if (/^\/session\/[^/]+\/(children|todo|diff)$/.test(url.pathname)) return json(route, [])
+    if (["/skill", "/command", "/lsp", "/formatter", "/permission", "/question", "/vcs/diff"].includes(url.pathname))
+      return json(route, [])
+    if (["/global/config", "/config", "/provider/auth", "/mcp", "/session/status"].includes(url.pathname))
+      return json(route, {})
+    if (url.pathname === "/provider")
+      return json(route, { all: [], connected: [], default: { providerID: "", modelID: "" } })
+    if (url.pathname === "/agent") return json(route, [{ name: "build", mode: "primary" }])
+    if (url.pathname === "/project" || url.pathname === "/project/current") {
+      const project = {
+        id: sessionA.projectID,
+        worktree: sessionA.directory,
+        vcs: "git",
+        time: { created: 1, updated: 1 },
+        sandboxes: [],
+      }
+      return json(route, url.pathname === "/project" ? [project] : project)
+    }
+    if (url.pathname === "/path")
+      return json(route, {
+        state: sessionA.directory,
+        config: sessionA.directory,
+        worktree: sessionA.directory,
+        directory: sessionA.directory,
+        home: sessionA.directory,
+      })
+    if (url.pathname === "/vcs") return json(route, { branch: "main", default_branch: "main" })
+    return json(route, {})
+  })
+}
+
+function json(route: Route, body: unknown, status = 200) {
+  return route.fulfill({
+    status,
+    contentType: "application/json",
+    headers: { "access-control-allow-origin": "*" },
+    body: JSON.stringify(body),
+  })
+}
+
+function sse(route: Route) {
+  return route.fulfill({ status: 200, contentType: "text/event-stream", body: ": ok\n\n" })
+}

packages/app/e2e/regression/terminal-composer-focus.spec.ts

@@ -0,0 +1,89 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { expect, test } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/TerminalComposerFocus"
+const projectID = "proj_terminal_composer_focus"
+const sessionID = "ses_terminal_composer_focus"
+const ptyID = "pty_terminal_composer_focus"
+
+test.use({ viewport: { width: 1440, height: 900 } })
+
+test("routes typing to the composer unless the open terminal is focused", async ({ page }) => {
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "terminal-composer-focus",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: { test: { id: "test", name: "Test", limit: { context: 200_000 } } },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "test" },
+    },
+    sessions: [
+      {
+        id: sessionID,
+        slug: "terminal-composer-focus",
+        projectID,
+        directory,
+        title: "Terminal composer focus",
+        version: "dev",
+        time: { created: 1700000000000, updated: 1700000000000 },
+      },
+    ],
+    pageMessages: () => ({ items: [] }),
+  })
+  await page.route("**/pty", (route) =>
+    route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify({ id: ptyID, title: "Terminal 1" }),
+    }),
+  )
+  await page.route(`**/pty/${ptyID}`, (route) =>
+    route.fulfill({ status: 200, contentType: "application/json", body: "{}" }),
+  )
+  await page.route(`**/pty/${ptyID}/connect-token*`, (route) =>
+    route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      headers: { "access-control-allow-origin": "*" },
+      body: JSON.stringify({ ticket: "e2e-ticket" }),
+    }),
+  )
+  await page.routeWebSocket(new RegExp(`/pty/${ptyID}/connect`), () => undefined)
+  await page.addInitScript(() => {
+    localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+  })
+
+  await page.goto(`/${base64Encode(directory)}/session/${sessionID}`)
+  await expectSessionTitle(page, "Terminal composer focus")
+
+  const composer = page.locator('[data-component="prompt-input"]')
+  const terminal = page.locator('[data-component="terminal"]')
+  await page.keyboard.press("Control+Backquote")
+  await expect(terminal).toBeVisible()
+  await expect.poll(() => terminal.evaluate((element) => element.contains(document.activeElement))).toBe(true)
+
+  await page.keyboard.type("x")
+  await expect(composer).toHaveText("")
+
+  await page.waitForTimeout(300)
+  await page.evaluate(() => (document.activeElement as HTMLElement | null)?.blur())
+  await page.keyboard.type("a")
+
+  await expect(composer).toBeFocused()
+  await expect(composer).toHaveText("a")
+})

packages/app/e2e/regression/terminal-hidden.spec.ts

@@ -7,7 +7,7 @@ const projectID = "proj_hidden_terminal_regression"
 const sessionID = "ses_hidden_terminal_regression"
 const title = "Hidden terminal regression"
 
-test("unmounts the terminal renderer while the pane is hidden", async ({ page }) => {
+test("unmounts the terminal panel while it is hidden", async ({ page }) => {
   await page.setViewportSize({ width: 1400, height: 900 })
   await mockOpenCodeServer(page, {
     directory,
@@ -64,13 +64,14 @@ test("unmounts the terminal renderer while the pane is hidden", async ({ page })
   await expect(page.locator('[data-component="terminal"]')).toBeVisible()
 
   await page.keyboard.press("Control+Backquote")
-  await expect(panel).toHaveAttribute("aria-hidden", "true")
+  await expect(panel).toHaveCount(0)
   await expect(page.locator('[data-component="terminal"]')).toHaveCount(0)
 
   await page.setViewportSize({ width: 1200, height: 700 })
   await expect(page.locator('[data-component="terminal"]')).toHaveCount(0)
 
   await page.keyboard.press("Control+Backquote")
+  await expect(panel).toBeVisible()
   await expect(page.locator('[data-component="terminal"]')).toBeVisible()
 })
 

packages/app/e2e/regression/terminal-tab-switch.spec.ts

@@ -0,0 +1,145 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { expect, test, type Page } from "@playwright/test"
+import { mockOpenCodeServer } from "../utils/mock-server"
+import { expectSessionTitle } from "../utils/waits"
+
+const directory = "C:/OpenCode/TerminalTabSwitch"
+const projectID = "proj_terminal_tab_switch"
+const sessionA = "ses_terminal_tab_a"
+const sessionB = "ses_terminal_tab_b"
+const titleA = "Alpha session"
+const titleB = "Beta session"
+const ptyID = "pty_tab_switch"
+const server = `http://${process.env.PLAYWRIGHT_SERVER_HOST ?? "127.0.0.1"}:${process.env.PLAYWRIGHT_SERVER_PORT ?? "4096"}`
+// Marks the terminal DOM node so a remount (fresh node) is detectable.
+const PROBE = "original"
+
+test.use({ viewport: { width: 1440, height: 900 } })
+
+// Terminals are workspace-scoped: switching between session tabs in the same
+// workspace must keep the terminal mounted and its PTY connection open instead
+// of tearing it down and reconnecting.
+test("keeps the terminal session alive when switching session tabs in a workspace", async ({ page }) => {
+  const connections = await setup(page)
+
+  await page.goto(sessionHref(sessionA))
+  await expectSessionTitle(page, titleA)
+
+  await page.keyboard.press("Control+Backquote")
+  const terminal = page.locator('[data-component="terminal"]')
+  await expect(terminal).toBeVisible()
+  await expect.poll(() => connections.length).toBe(1)
+  await writeProbe(page)
+
+  await switchTab(page, titleB)
+  await expectSessionTitle(page, titleB)
+  await expect(terminal).toBeVisible()
+  expect(await readProbe(page)).toBe(PROBE)
+  expect(connections.length).toBe(1)
+
+  await switchTab(page, titleA)
+  await expectSessionTitle(page, titleA)
+  await expect(terminal).toBeVisible()
+  expect(await readProbe(page)).toBe(PROBE)
+  expect(connections.length).toBe(1)
+})
+
+type Probed = HTMLElement & { __e2eProbe?: string }
+
+async function switchTab(page: Page, title: string) {
+  await page.locator("[data-titlebar-tab-slot]", { hasText: title }).click()
+}
+
+async function writeProbe(page: Page) {
+  await page.locator('[data-component="terminal"]').evaluate((el, probe) => {
+    ;(el as Probed).__e2eProbe = probe
+  }, PROBE)
+}
+
+async function readProbe(page: Page) {
+  return page.locator('[data-component="terminal"]').evaluate((el) => (el as Probed).__e2eProbe)
+}
+
+async function setup(page: Page) {
+  await mockOpenCodeServer(page, {
+    directory,
+    project: {
+      id: projectID,
+      worktree: directory,
+      vcs: "git",
+      name: "terminal-tab-switch",
+      time: { created: 1700000000000, updated: 1700000000000 },
+      sandboxes: [],
+    },
+    provider: {
+      all: [
+        {
+          id: "opencode",
+          name: "OpenCode",
+          models: { test: { id: "test", name: "Test", limit: { context: 200_000 } } },
+        },
+      ],
+      connected: ["opencode"],
+      default: { providerID: "opencode", modelID: "test" },
+    },
+    sessions: [session(sessionA, titleA, 1700000000000), session(sessionB, titleB, 1700000001000)],
+    pageMessages: () => ({ items: [] }),
+  })
+  await page.route("**/pty", (route) =>
+    route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      body: JSON.stringify({ id: ptyID, title: "Terminal 1" }),
+    }),
+  )
+  await page.route(`**/pty/${ptyID}`, (route) =>
+    route.fulfill({ status: 200, contentType: "application/json", body: "{}" }),
+  )
+  await page.route(`**/pty/${ptyID}/connect-token*`, (route) =>
+    route.fulfill({
+      status: 200,
+      contentType: "application/json",
+      headers: { "access-control-allow-origin": "*" },
+      body: JSON.stringify({ ticket: "e2e-ticket" }),
+    }),
+  )
+  const connections: string[] = []
+  await page.routeWebSocket(new RegExp(`/pty/${ptyID}/connect`), (ws) => {
+    connections.push(ws.url())
+  })
+
+  await page.addInitScript(
+    ({ directory, server, sessions }) => {
+      localStorage.setItem("settings.v3", JSON.stringify({ general: { newLayoutDesigns: true } }))
+      localStorage.setItem(
+        "opencode.global.dat:server",
+        JSON.stringify({
+          projects: { local: [{ worktree: directory, expanded: true }] },
+          lastProject: { local: directory },
+        }),
+      )
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify(sessions.map((sessionId: string) => ({ type: "session", server, sessionId }))),
+      )
+    },
+    { directory, server, sessions: [sessionA, sessionB] },
+  )
+  return connections
+}
+
+function session(id: string, title: string, created: number) {
+  return {
+    id,
+    slug: id,
+    projectID,
+    directory,
+    title,
+    version: "dev",
+    time: { created, updated: created },
+  }
+}
+
+function sessionHref(sessionID: string) {
+  return `/server/${base64Encode(server)}/session/${sessionID}`
+}

packages/app/e2e/smoke/session-timeline.spec.ts

@@ -127,7 +127,7 @@ test.describe("smoke: session timeline", () => {
     await page.addInitScript(
       ({ dirBase64, sourceID, targetID }) => {
         localStorage.setItem(
-          "opencode.global.dat:tabs",
+          "opencode.window.browser.dat:tabs",
           JSON.stringify(
             [sourceID, targetID].map((sessionId) => ({
               type: "session",
@@ -253,7 +253,7 @@ test.describe("smoke: session timeline", () => {
     await page.addInitScript(
       ({ dirBase64, sourceID, targetID }) => {
         localStorage.setItem(
-          "opencode.global.dat:tabs",
+          "opencode.window.browser.dat:tabs",
           JSON.stringify(
             [sourceID, targetID].map((sessionId) => ({
               type: "session",

packages/app/e2e/tsconfig.json

@@ -5,5 +5,13 @@
     "rootDir": "..",
     "types": ["node", "bun"]
   },
-  "include": ["./**/*.ts"]
+  "include": [
+    "./performance/timeline-stability/**/*.spec.ts",
+    "./performance/timeline-stability/fixture.test.ts",
+    "./performance/timeline-stability/fixture.ts",
+    "./performance/unit/visual-stability.test.ts",
+    "./regression/new-session-panel-corner.spec.ts",
+    "./regression/session-timeline-context-resize.spec.ts",
+    "./utils/**/*.ts"
+  ]
 }

packages/app/e2e/utils/mock-server.ts

@@ -1,7 +1,7 @@
 import type { Page, Route } from "@playwright/test"
 
 const emptyList = new Set(["/skill", "/command", "/lsp", "/formatter", "/vcs/status", "/vcs/diff"])
-const emptyObject = new Set(["/global/config", "/config", "/provider/auth", "/mcp", "/session/status"])
+const emptyObject = new Set(["/global/config", "/config", "/provider/auth", "/mcp", "/experimental/resource"])
 
 export interface MockServerConfig {
   provider: unknown
@@ -11,12 +11,18 @@ export interface MockServerConfig {
   pageMessages: (sessionId: string, limit: number, before?: string) => { items: unknown[]; cursor?: string }
   vcsDiff?: unknown[]
   messageDelay?: number
+  beforeMessagesResponse?: (input: { sessionID: string; before?: string }) => Promise<void>
   onMessages?: (input: { sessionID: string; before?: string; phase: "start" | "end" }) => void
+  message?: (sessionID: string, messageID: string) => unknown
+  onMessage?: (input: { sessionID: string; messageID: string }) => void
   events?: () => unknown[]
   eventRetry?: number
   todos?: (sessionID: string) => unknown[]
   permissions?: unknown[] | (() => unknown[])
   questions?: unknown[] | (() => unknown[])
+  fileList?: (path: string) => unknown | Promise<unknown>
+  fileContent?: (path: string) => unknown | Promise<unknown>
+  sessionStatus?: unknown
 }
 
 export async function mockOpenCodeServer(page: Page, config: MockServerConfig) {
@@ -49,11 +55,25 @@ export async function mockOpenCodeServer(page: Page, config: MockServerConfig) {
     const path = url.pathname
     if (path === "/global/event" || path === "/event") return sse(route, config.events?.(), config.eventRetry)
     if (path === "/global/health") return json(route, { healthy: true })
+    if (path === "/experimental/capabilities") return json(route, { backgroundSubagents: false })
     if (path === "/permission")
       return json(route, typeof config.permissions === "function" ? config.permissions() : (config.permissions ?? []))
     if (path === "/question")
       return json(route, typeof config.questions === "function" ? config.questions() : (config.questions ?? []))
+    if (path === "/session/status") return json(route, config.sessionStatus ?? {})
     if (path === "/vcs/diff" && config.vcsDiff) return json(route, config.vcsDiff)
+    if (path === "/file" && config.fileList)
+      return json(route, await config.fileList(url.searchParams.get("path") ?? ""))
+    if (path === "/file/content" && config.fileContent)
+      return json(route, await config.fileContent(url.searchParams.get("path") ?? ""))
+    if (path === "/api/reference")
+      return json(route, {
+        location: {
+          directory: config.directory,
+          project: { id: (config.project as { id?: string }).id, directory: config.directory },
+        },
+        data: [],
+      })
     if (emptyObject.has(path)) return json(route, {})
     if (emptyList.has(path)) return json(route, [])
     if (path in staticRoutes) return json(route, staticRoutes[path])
@@ -64,6 +84,18 @@ export async function mockOpenCodeServer(page: Page, config: MockServerConfig) {
       return json(route, session ?? {})
     }
 
+    const projectMatch = path.match(/^\/project\/([^/]+)$/)
+    if (projectMatch) return json(route, config.project)
+
+    const messageMatch = path.match(/^\/session\/([^/]+)\/message\/([^/]+)$/)
+    if (messageMatch) {
+      config.onMessage?.({ sessionID: messageMatch[1]!, messageID: messageMatch[2]! })
+      if (config.messageDelay !== undefined) await new Promise((resolve) => setTimeout(resolve, config.messageDelay))
+      const message = config.message?.(messageMatch[1]!, messageMatch[2]!)
+      if (message === undefined) return json(route, { error: "Message not found" }, undefined, 404)
+      return json(route, message)
+    }
+
     const todoMatch = path.match(/^\/session\/([^/]+)\/todo$/)
     if (todoMatch) return json(route, config.todos?.(todoMatch[1]!) ?? [])
     if (/^\/session\/[^/]+\/(children|diff)$/.test(path)) return json(route, [])
@@ -74,7 +106,8 @@ export async function mockOpenCodeServer(page: Page, config: MockServerConfig) {
       const before = token ? cursors.get(token) : undefined
       if (token && !before) return json(route, { error: "Invalid cursor" }, undefined, 400)
       config.onMessages?.({ sessionID: messagesMatch[1], before, phase: "start" })
-      if (config.messageDelay) await new Promise((resolve) => setTimeout(resolve, config.messageDelay))
+      await config.beforeMessagesResponse?.({ sessionID: messagesMatch[1]!, before })
+      if (config.messageDelay !== undefined) await new Promise((resolve) => setTimeout(resolve, config.messageDelay))
       const limit = Number(url.searchParams.get("limit") ?? 80)
       const pageData = config.pageMessages(messagesMatch[1], limit, before)
       config.onMessages?.({ sessionID: messagesMatch[1], before, phase: "end" })

packages/app/e2e/utils/sse-transport.ts

@@ -0,0 +1,284 @@
+import type { Page } from "@playwright/test"
+
+export type SseConnectionRecord = {
+  id: number
+  url: string
+  path: "/global/event" | "/event"
+  headers: Record<string, string>
+  openedAt: number
+  endedAt?: number
+  endedBy?: "close" | "disconnect" | "error" | "abort"
+  error?: string
+}
+
+export type SseDeliveryAcknowledgement = {
+  deliveryID: number
+  connectionID: number
+  bytes: number
+  chunkCount: number
+  deliveredAt: number
+  eventID?: string
+}
+
+export type SseEventOptions = {
+  id?: string
+  event?: string
+  retry?: number
+  marker?: string
+}
+
+export type SseTransport<T> = {
+  server: string
+  waitForConnection(options?: { after?: number; timeout?: number }): Promise<SseConnectionRecord>
+  send(payload: T, options?: SseEventOptions): Promise<SseDeliveryAcknowledgement>
+  burst(payloads: readonly T[], options?: readonly SseEventOptions[]): Promise<SseDeliveryAcknowledgement[]>
+  split(payload: T, cuts: readonly number[], options?: SseEventOptions): Promise<SseDeliveryAcknowledgement>
+  heartbeat(options?: SseEventOptions): Promise<SseDeliveryAcknowledgement>
+  writeRaw(value: string | Uint8Array, cuts?: readonly number[], marker?: string): Promise<SseDeliveryAcknowledgement>
+  close(): Promise<void>
+  disconnect(message?: string): Promise<void>
+  error(message?: string): Promise<void>
+  connections(): Promise<SseConnectionRecord[]>
+  acknowledgements(): Promise<SseDeliveryAcknowledgement[]>
+}
+
+type BrowserCommand<T> =
+  | { type: "send"; deliveries: { payload: T; options?: SseEventOptions }[]; burst: boolean; cuts?: number[] }
+  | { type: "raw"; bytes: number[]; cuts?: number[]; marker?: string }
+  | { type: "end"; mode: "close" | "disconnect" | "error"; message?: string }
+  | { type: "connections" }
+  | { type: "acknowledgements" }
+
+type BrowserTransport = Window & {
+  __testSseTransport?: {
+    command: (command: BrowserCommand<unknown>) => unknown
+  }
+}
+
+export async function installSseTransport<T>(
+  page: Page,
+  options: { server: string; retry?: number },
+): Promise<SseTransport<T>> {
+  const server = new URL(options.server).origin
+  await page.addInitScript(
+    ({ server, retry }) => {
+      type Connection = SseConnectionRecord & { controller: ReadableStreamDefaultController<Uint8Array> }
+      type ProbeWindow = Window & {
+        __visualStabilityProbe?: { startedAt: number; markers: { at: number; label: string }[] }
+      }
+      const originalFetch = window.fetch.bind(window)
+      const connections: Connection[] = []
+      const acknowledgements: SseDeliveryAcknowledgement[] = []
+      const encoder = new TextEncoder()
+      let nextConnectionID = 0
+      let nextDeliveryID = 0
+
+      const current = () => connections.findLast((connection) => connection.endedAt === undefined)
+      const chunks = (bytes: Uint8Array, cuts?: readonly number[]) => {
+        const boundaries = [...new Set(cuts ?? [])]
+          .filter((cut) => Number.isInteger(cut) && cut > 0 && cut < bytes.byteLength)
+          .sort((a, b) => a - b)
+        return [0, ...boundaries].map((start, index) => bytes.slice(start, boundaries[index] ?? bytes.byteLength))
+      }
+      const marker = (label?: string) => {
+        if (!label) return
+        const probe = (window as ProbeWindow).__visualStabilityProbe
+        if (!probe) return
+        probe.markers.push({ at: performance.now() - probe.startedAt, label })
+      }
+      const frame = (payload: unknown, eventOptions: SseEventOptions = {}) =>
+        [
+          eventOptions.event === undefined ? "" : `event: ${eventOptions.event}\n`,
+          eventOptions.id === undefined ? "" : `id: ${eventOptions.id}\n`,
+          eventOptions.retry === undefined ? "" : `retry: ${eventOptions.retry}\n`,
+          `data: ${JSON.stringify(payload)}\n\n`,
+        ].join("")
+      const acknowledge = (
+        connection: Connection,
+        bytes: number,
+        chunkCount: number,
+        eventID?: string,
+      ): SseDeliveryAcknowledgement => {
+        const acknowledgement = {
+          deliveryID: ++nextDeliveryID,
+          connectionID: connection.id,
+          bytes,
+          chunkCount,
+          deliveredAt: performance.now(),
+          ...(eventID === undefined ? {} : { eventID }),
+        }
+        acknowledgements.push(acknowledgement)
+        return acknowledgement
+      }
+      const end = (mode: "close" | "disconnect" | "error", message?: string) => {
+        const connection = current()
+        if (!connection) throw new Error("SSE transport has no active connection")
+        connection.endedAt = performance.now()
+        connection.endedBy = mode
+        if (message) connection.error = message
+        if (mode === "close") {
+          connection.controller.close()
+          return
+        }
+        const error = new DOMException(
+          message ?? "SSE connection disconnected",
+          mode === "error" ? "Error" : "NetworkError",
+        )
+        connection.controller.error(error)
+      }
+
+      const command = (input: BrowserCommand<unknown>) => {
+        if (input.type === "connections")
+          return connections.map(({ controller: _controller, ...connection }) => connection)
+        if (input.type === "acknowledgements") return acknowledgements
+        if (input.type === "end") return end(input.mode, input.message)
+        const connection = current()
+        if (!connection) throw new Error("SSE transport has no active connection")
+        if (input.type === "raw") {
+          marker(input.marker)
+          const output = chunks(new Uint8Array(input.bytes), input.cuts)
+          output.forEach((chunk) => connection.controller.enqueue(chunk))
+          return acknowledge(connection, input.bytes.length, output.length)
+        }
+        const encoded = input.deliveries.map((delivery) => ({
+          delivery,
+          bytes: encoder.encode(frame(delivery.payload, delivery.options)),
+        }))
+        encoded.forEach((item) => marker(item.delivery.options?.marker))
+        if (input.burst) {
+          const bytes = encoder.encode(
+            encoded.map((item) => frame(item.delivery.payload, item.delivery.options)).join(""),
+          )
+          connection.controller.enqueue(bytes)
+          return encoded.map((item) => acknowledge(connection, item.bytes.byteLength, 1, item.delivery.options?.id))
+        }
+        const output = chunks(encoded[0]!.bytes, input.cuts)
+        output.forEach((chunk) => connection.controller.enqueue(chunk))
+        return acknowledge(connection, encoded[0]!.bytes.byteLength, output.length, encoded[0]!.delivery.options?.id)
+      }
+
+      ;(window as BrowserTransport).__testSseTransport = { command }
+      const fetch = (input: RequestInfo | URL, init?: RequestInit) => {
+        const request = new Request(input, init)
+        const url = new URL(request.url)
+        if (url.origin !== server || (url.pathname !== "/global/event" && url.pathname !== "/event"))
+          return originalFetch(input, init)
+
+        const id = ++nextConnectionID
+        const record = {
+          id,
+          url: url.href,
+          path: url.pathname,
+          headers: Object.fromEntries(request.headers.entries()),
+          openedAt: performance.now(),
+        } as Connection
+        const stream = new ReadableStream<Uint8Array>({
+          start(controller) {
+            record.controller = controller
+            connections.push(record)
+            if (retry !== undefined) controller.enqueue(encoder.encode(`retry: ${retry}\n\n`))
+            request.signal.addEventListener(
+              "abort",
+              () => {
+                if (record.endedAt !== undefined) return
+                record.endedAt = performance.now()
+                record.endedBy = "abort"
+                controller.error(request.signal.reason ?? new DOMException("The operation was aborted", "AbortError"))
+              },
+              { once: true },
+            )
+          },
+          cancel() {
+            if (record.endedAt !== undefined) return
+            record.endedAt = performance.now()
+            record.endedBy = "disconnect"
+          },
+        })
+        return Promise.resolve(
+          new Response(stream, {
+            status: 200,
+            headers: {
+              "cache-control": "no-cache",
+              "content-type": "text/event-stream",
+            },
+          }),
+        )
+      }
+      Object.defineProperty(window, "fetch", { configurable: true, writable: true, value: fetch })
+    },
+    { server, retry: options.retry },
+  )
+
+  const command = <Result>(input: BrowserCommand<T>) =>
+    page.evaluate((input) => {
+      const transport = (window as BrowserTransport).__testSseTransport
+      if (!transport) throw new Error("SSE transport was not installed before page load")
+      return transport.command(input as BrowserCommand<unknown>)
+    }, input) as Promise<Result>
+
+  return {
+    server,
+    async waitForConnection(input = {}) {
+      await page.waitForFunction(
+        (after) => {
+          const transport = (window as BrowserTransport).__testSseTransport
+          const connections = transport?.command({ type: "connections" }) as SseConnectionRecord[] | undefined
+          return connections?.some((connection) => connection.id > after)
+        },
+        input.after ?? 0,
+        { timeout: input.timeout },
+      )
+      return (await command<SseConnectionRecord[]>({ type: "connections" })).findLast(
+        (connection) => connection.id > (input.after ?? 0),
+      )!
+    },
+    send(payload, eventOptions) {
+      return command({ type: "send", deliveries: [{ payload, options: eventOptions }], burst: false })
+    },
+    burst(payloads, eventOptions = []) {
+      return command({
+        type: "send",
+        deliveries: payloads.map((payload, index) => ({ payload, options: eventOptions[index] })),
+        burst: true,
+      })
+    },
+    split(payload, cuts, eventOptions) {
+      return command({ type: "send", deliveries: [{ payload, options: eventOptions }], burst: false, cuts: [...cuts] })
+    },
+    heartbeat(eventOptions) {
+      return command({
+        type: "send",
+        deliveries: [
+          {
+            payload: { directory: "global", payload: { type: "server.heartbeat", properties: {} } } as T,
+            options: eventOptions,
+          },
+        ],
+        burst: false,
+      })
+    },
+    writeRaw(value, cuts, marker) {
+      return command({
+        type: "raw",
+        bytes: Array.from(typeof value === "string" ? new TextEncoder().encode(value) : value),
+        cuts: cuts ? [...cuts] : undefined,
+        marker,
+      })
+    },
+    close() {
+      return command({ type: "end", mode: "close" })
+    },
+    disconnect(message) {
+      return command({ type: "end", mode: "disconnect", message })
+    },
+    error(message) {
+      return command({ type: "end", mode: "error", message })
+    },
+    connections() {
+      return command({ type: "connections" })
+    },
+    acknowledgements() {
+      return command({ type: "acknowledgements" })
+    },
+  }
+}

packages/app/e2e/utils/visual-stability.ts

@@ -0,0 +1,54 @@
+import type { Page, TestInfo } from "@playwright/test"
+import { analyzeVisualObservations, analyzeVisualTraceByMarker } from "./visual-stability/analyzer"
+import { legacyVisualPlan, type LegacyVisualStabilityOptions } from "./visual-stability/invariant"
+import type { CapturedFrame, VisualStabilityTrace } from "./visual-stability/model"
+import { markVisualProbe, startVisualProbe, stopVisualProbe } from "./visual-stability/probe"
+import type { VisualRegionDefinition } from "./visual-stability/regions"
+import { reportVisualStability } from "./visual-stability/reporter"
+
+export * from "./visual-stability/index"
+
+const capturedFrames = Symbol("capturedFrames")
+
+export async function startVisualStabilityProbe(page: Page, regions: Record<string, VisualRegionDefinition>) {
+  await startVisualProbe(page, regions)
+}
+
+export async function stopVisualStabilityProbe(page: Page) {
+  const result = await stopVisualProbe(page)
+  const trace: VisualStabilityTrace = { markers: result.markers, samples: result.samples }
+  Object.defineProperty(trace, capturedFrames, { value: result.frames })
+  return trace
+}
+
+export async function markVisualStability(page: Page, label: string) {
+  await markVisualProbe(page, label)
+}
+
+export function analyzeVisualStability(trace: VisualStabilityTrace, options: LegacyVisualStabilityOptions = {}) {
+  return analyzeVisualObservations(trace.samples, legacyVisualPlan(options))
+}
+
+export function analyzeVisualStabilityByMarker(
+  trace: VisualStabilityTrace,
+  options: LegacyVisualStabilityOptions = {},
+) {
+  return analyzeVisualTraceByMarker(trace, legacyVisualPlan(options))
+}
+
+export async function expectVisualStability(
+  testInfo: TestInfo,
+  name: string,
+  trace: VisualStabilityTrace,
+  options: LegacyVisualStabilityOptions = {},
+) {
+  await reportVisualStability(
+    testInfo,
+    name,
+    {
+      ...trace,
+      frames: (trace as VisualStabilityTrace & { [capturedFrames]?: CapturedFrame[] })[capturedFrames] ?? [],
+    },
+    legacyVisualPlan(options),
+  )
+}

packages/app/e2e/utils/visual-stability/analyzer.ts

@@ -0,0 +1,209 @@
+import type { VisualInvariant, VisualPlan } from "./invariant"
+import type { VisualObservation, VisualStabilityTrace } from "./model"
+
+export function analyzeVisualObservations<RegionName extends string>(
+  observations: readonly VisualObservation<RegionName>[],
+  plan: VisualPlan<RegionName>,
+) {
+  const issues: string[] = []
+  const invariants = plan.invariants
+  const names = [...new Set(observations.flatMap((sample) => Object.keys(sample.regions) as RegionName[]))]
+  const required = regions(invariants, "required")
+  const continuousAny = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "continuous-any" }> =>
+      invariant.type === "continuous-any",
+  )
+  const unique = new Set(regions(invariants, "unique"))
+  const stable = new Set(regions(invariants, "stable"))
+  const fixed = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "fixed" }> => invariant.type === "fixed",
+  )
+  const opacity = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "opacity" }> => invariant.type === "opacity",
+  )
+  const continuity = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "continuity" }> =>
+      invariant.type === "continuity",
+  )
+  const motion = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "motion" }> => invariant.type === "motion",
+  )
+  const labelStability = invariants.filter(
+    (invariant): invariant is Extract<VisualInvariant<RegionName>, { type: "label-stability" }> =>
+      invariant.type === "label-stability",
+  )
+
+  for (const name of new Set(required)) {
+    if (!observations.some((sample) => sample.regions[name]?.visible)) issues.push(`${name} never rendered`)
+  }
+  for (const invariant of continuousAny) {
+    if (!invariant.regions.some((name) => observations.some((sample) => sample.regions[name]?.visible)))
+      issues.push(`${invariant.regions.join(" | ")} never rendered`)
+  }
+
+  for (const name of names) {
+    const samples = observations.flatMap((observation) => {
+      const region = observation.regions[name]
+      if (!region) return []
+      const clipped =
+        observation.viewport && (region.bottom <= observation.viewport.top || region.top >= observation.viewport.bottom)
+      return [{ at: observation.at, ...region, visible: region.visible && !clipped }]
+    })
+    const visible = samples.filter((sample) => sample.visible)
+    if (visible.length === 0) continue
+    if (unique.has(name)) {
+      const duplicate = samples.find((sample) => sample.count > 1)
+      if (duplicate) issues.push(`${name} appeared ${duplicate.count} times at ${Math.round(duplicate.at)}ms`)
+    }
+    if (stable.has(name)) {
+      const identities = [...new Set(visible.map((sample) => sample.node).filter((node) => node > 0))]
+      if (identities.length > 1) issues.push(`${name} remounted ${identities.length - 1} times`)
+    }
+    for (const invariant of fixed.filter((invariant) => includes(invariant.regions, name))) {
+      const origin = visible[0]
+      const movement = origin ? Math.max(0, ...visible.map((sample) => Math.abs(sample.top - origin.top))) : 0
+      if (movement > (invariant.tolerance ?? 1))
+        issues.push(`${name} moved ${Math.round(movement * 10) / 10}px in the viewport`)
+    }
+    for (const invariant of opacity.filter((invariant) => includes(invariant.regions, name))) {
+      for (const sample of visible) {
+        if (sample.opacity < (invariant.floor ?? 0.65))
+          issues.push(`${name} opacity fell to ${sample.opacity} at ${Math.round(sample.at)}ms`)
+      }
+    }
+    if (continuity.some((invariant) => includes(invariant.regions, name))) {
+      const firstPresent = samples.findIndex((sample) => sample.present)
+      const lastPresent = samples.findLastIndex((sample) => sample.present)
+      if (samples.slice(firstPresent, lastPresent + 1).some((sample) => !sample.present))
+        issues.push(`${name} disappeared between present frames`)
+      const firstVisible = samples.findIndex((sample) => sample.visible)
+      const lastVisible = samples.findLastIndex((sample) => sample.visible)
+      if (
+        firstVisible >= 0 &&
+        samples.slice(firstVisible, lastVisible + 1).some((sample) => !sample.visible && sample.inViewport)
+      )
+        issues.push(`${name} blanked between visible frames`)
+    }
+    for (const invariant of motion.filter((invariant) => includes(invariant.regions, name))) {
+      for (const metric of ["top", "bottom", "width", "height"] as const) {
+        const directions = visible
+          .slice(1)
+          .map((sample, index) => sample[metric] - visible[index]![metric])
+          .filter((delta) => Math.abs(delta) > (invariant.tolerance ?? 1))
+          .map(Math.sign)
+        const reversals = directions.slice(1).filter((direction, index) => direction !== directions[index]).length
+        const allowed =
+          metric === "top" || metric === "bottom"
+            ? (invariant.maxPositionReversals ?? invariant.maxReversals ?? 1)
+            : (invariant.maxReversals ?? 1)
+        if (reversals > allowed) issues.push(`${name} ${metric} reversed ${reversals} times`)
+      }
+    }
+    if (labelStability.some((invariant) => includes(invariant.regions, name))) {
+      const labels = samples
+        .map((sample) => sample.label)
+        .filter((label) => label.length > 0)
+        .filter((label, index, all) => label !== all[index - 1])
+      if (labels.some((label, index) => labels.indexOf(label) !== index))
+        issues.push(`${name} label reverted: ${labels.join(" -> ")}`)
+    }
+  }
+
+  if (invariants.some((invariant) => invariant.type === "preserve-bottom-anchor")) {
+    const viewports = observations.flatMap((sample) => (sample.viewport ? [sample.viewport] : []))
+    if (viewports[0] && viewports[0].distanceFromBottom <= 4) {
+      const lost = viewports.find((viewport) => viewport.distanceFromBottom > 4)
+      if (lost) issues.push(`bottom anchor moved to ${lost.distanceFromBottom}px`)
+    }
+  }
+  if (invariants.some((invariant) => invariant.type === "acquire-bottom-anchor")) {
+    const final = observations.findLast((sample) => sample.viewport)?.viewport
+    if (!final || final.distanceFromBottom > 4)
+      issues.push(`did not acquire bottom anchor${final ? ` (${final.distanceFromBottom}px away)` : ""}`)
+  }
+
+  for (const invariant of continuousAny) {
+    const active = observations.map((sample) => invariant.regions.some((name) => sample.regions[name]?.visible))
+    const first = active.indexOf(true)
+    const last = active.lastIndexOf(true)
+    if (first >= 0 && active.slice(first, last + 1).some((value) => !value))
+      issues.push(`${invariant.regions.join(" | ")} blanked between visible frames`)
+  }
+
+  for (const invariant of invariants.filter(
+    (item): item is Extract<VisualInvariant<RegionName>, { type: "flow" }> => item.type === "flow",
+  )) {
+    for (const [before, after] of invariant.regions
+      .slice(1)
+      .map((after, index) => [invariant.regions[index]!, after])) {
+      let maximum: { overlap: number; at: number } | undefined
+      let inverted: { at: number } | undefined
+      for (const sample of observations) {
+        const first = sample.regions[before]
+        const second = sample.regions[after]
+        if (!first?.visible || !second?.visible) continue
+        if (
+          sample.viewport &&
+          (first.bottom <= sample.viewport.top ||
+            first.top >= sample.viewport.bottom ||
+            second.bottom <= sample.viewport.top ||
+            second.top >= sample.viewport.bottom)
+        )
+          continue
+        const overlap = first.bottom - second.top
+        if (first.top > second.top && !inverted) inverted = { at: sample.at }
+        if (overlap > (invariant.overlapTolerance ?? 0.5) && (!maximum || overlap > maximum.overlap))
+          maximum = { overlap, at: sample.at }
+      }
+      if (inverted) issues.push(`${before} rendered after ${after} at ${Math.round(inverted.at)}ms`)
+      if (maximum)
+        issues.push(
+          `${before} overlapped ${after} by ${Math.round(maximum.overlap * 10) / 10}px at ${Math.round(maximum.at)}ms`,
+        )
+    }
+  }
+  return [...new Set(issues)]
+}
+
+export function analyzeVisualTraceByMarker<RegionName extends string>(
+  trace: VisualStabilityTrace<RegionName>,
+  plan: VisualPlan<RegionName>,
+) {
+  if (trace.markers.length === 0) return analyzeVisualObservations(trace.samples, plan)
+  const required = [...new Set(plan.markerRequired ?? regions(plan.invariants, "required"))].flatMap((name) =>
+    trace.samples.some((sample) => sample.regions[name]?.visible) ? [] : [`${name} never rendered`],
+  )
+  const withoutRequired = plan.invariants.filter((invariant) => invariant.type !== "required")
+  const windows = trace.markers.flatMap((marker, index) => {
+    const end = trace.markers[index + 1]?.at ?? Infinity
+    const before = trace.samples.findLast((sample) => sample.at < marker.at)
+    const samples = [
+      ...(before ? [before] : []),
+      ...trace.samples.filter((sample) => sample.at >= marker.at && sample.at < end),
+    ]
+    if (samples.length < 2) return []
+    return analyzeVisualObservations(samples, { ...plan, perMarker: false, invariants: withoutRequired }).map(
+      (issue) => `${marker.label}: ${issue}`,
+    )
+  })
+  const aggregateMotion =
+    plan.aggregateMotion === false
+      ? []
+      : analyzeVisualObservations(trace.samples, {
+          invariants: plan.invariants.filter((invariant) => invariant.type === "motion"),
+        }).filter((issue) => / (?:top|bottom|width|height) reversed \d+ times$/.test(issue))
+  return [...new Set([...required, ...aggregateMotion, ...windows])]
+}
+
+function regions<RegionName extends string, Type extends VisualInvariant<RegionName>["type"]>(
+  invariants: readonly VisualInvariant<RegionName>[],
+  type: Type,
+) {
+  return invariants.flatMap((invariant) =>
+    invariant.type === type && "regions" in invariant && invariant.regions !== "all" ? [...invariant.regions] : [],
+  ) as RegionName[]
+}
+
+function includes<RegionName extends string>(regions: readonly RegionName[] | "all", name: RegionName) {
+  return regions === "all" || regions.includes(name)
+}

packages/app/e2e/utils/visual-stability/capture.ts

@@ -0,0 +1,51 @@
+import type { CDPSession, Page } from "@playwright/test"
+import type { CapturedFrame } from "./model"
+
+export type VisualCapture = {
+  session: CDPSession
+  frames: CapturedFrame[]
+  startedAtEpoch: number
+  running: boolean
+  capture: Promise<void>
+}
+
+export async function startVisualCapture(page: Page, startedAtEpoch: number) {
+  if (process.env.OPENCODE_STABILITY_CAPTURE !== "1") return
+  const session = await page.context().newCDPSession(page)
+  await session.send("Page.enable")
+  const recording: VisualCapture = {
+    session,
+    frames: [],
+    startedAtEpoch,
+    running: true,
+    capture: Promise.resolve(),
+  }
+  recording.capture = (async () => {
+    try {
+      while (recording.running && recording.frames.length < 900) {
+        const frame = await session.send("Page.captureScreenshot", {
+          format: "jpeg",
+          quality: 80,
+          captureBeyondViewport: false,
+          optimizeForSpeed: true,
+        })
+        recording.frames.push({ at: Date.now() - recording.startedAtEpoch, data: frame.data })
+        await new Promise((resolve) => setTimeout(resolve, 50))
+      }
+    } catch {
+      recording.running = false
+    }
+  })()
+  return recording
+}
+
+export async function stopVisualCapture(recording: VisualCapture | undefined) {
+  if (!recording) return []
+  recording.running = false
+  try {
+    await recording.capture
+  } finally {
+    await recording.session.detach().catch(() => undefined)
+  }
+  return recording.frames
+}

packages/app/e2e/utils/visual-stability/index.ts

@@ -0,0 +1,8 @@
+export * from "./analyzer"
+export * from "./capture"
+export * from "./invariant"
+export * from "./model"
+export * from "./probe"
+export * from "./regions"
+export * from "./reporter"
+export * from "./scenario"

packages/app/e2e/utils/visual-stability/invariant.ts

@@ -0,0 +1,112 @@
+import type { VisualRegionDefinition } from "./regions"
+
+type RegionSet<RegionName extends string> = readonly RegionName[] | "all"
+
+export type VisualInvariant<RegionName extends string = string> =
+  | { type: "required"; regions: readonly RegionName[] }
+  | { type: "continuous-any"; regions: readonly RegionName[] }
+  | { type: "unique"; regions: readonly RegionName[] }
+  | { type: "stable"; regions: readonly RegionName[] }
+  | { type: "fixed"; regions: readonly RegionName[]; tolerance?: number }
+  | { type: "opacity"; regions: RegionSet<RegionName>; floor?: number }
+  | {
+      type: "motion"
+      regions: RegionSet<RegionName>
+      tolerance?: number
+      maxReversals?: number
+      maxPositionReversals?: number
+    }
+  | { type: "continuity"; regions: RegionSet<RegionName> }
+  | { type: "label-stability"; regions: RegionSet<RegionName> }
+  | { type: "flow"; regions: readonly RegionName[]; overlapTolerance?: number }
+  | { type: "preserve-bottom-anchor" }
+  | { type: "acquire-bottom-anchor" }
+
+export type VisualPlan<RegionName extends string = string> = {
+  regionNames?: readonly RegionName[]
+  invariants: readonly VisualInvariant<RegionName>[]
+  markerRequired?: readonly RegionName[]
+  perMarker?: boolean
+  aggregateMotion?: boolean
+}
+
+export type LegacyVisualStabilityOptions<RegionName extends string = string> = {
+  flow?: RegionName[]
+  motionTolerance?: number
+  opacityFloor?: number
+  overlapTolerance?: number
+  maxReversals?: number
+  maxPositionReversals?: number
+  stable?: RegionName[]
+  fixed?: RegionName[]
+  motion?: RegionName[]
+  unique?: RegionName[]
+  preserveBottomAnchor?: boolean
+  acquireBottomAnchor?: boolean
+  perMarker?: boolean
+  continuousAny?: RegionName[][]
+  required?: RegionName[]
+  aggregateMotion?: boolean
+  inferRequired?: boolean
+}
+
+export function visualPlan<const Regions extends Record<string, VisualRegionDefinition>>(
+  regions: Regions,
+  invariants: readonly VisualInvariant<Extract<keyof Regions, string>>[],
+  options: Omit<VisualPlan<Extract<keyof Regions, string>>, "regionNames" | "invariants"> = {},
+): VisualPlan<Extract<keyof Regions, string>> {
+  return { ...options, regionNames: Object.keys(regions) as Extract<keyof Regions, string>[], invariants }
+}
+
+export function legacyVisualPlan<RegionName extends string>(
+  options: LegacyVisualStabilityOptions<RegionName> = {},
+): VisualPlan<RegionName> {
+  const inferred =
+    options.inferRequired === false
+      ? []
+      : [
+          ...(options.stable ?? []),
+          ...(options.fixed ?? []),
+          ...(options.unique ?? []),
+          ...(options.motion ?? []),
+          ...(options.flow ?? []),
+        ]
+  return {
+    perMarker: options.perMarker,
+    aggregateMotion: options.aggregateMotion,
+    markerRequired: [
+      ...(options.required ?? []),
+      ...(options.stable ?? []),
+      ...(options.fixed ?? []),
+      ...(options.unique ?? []),
+      ...(options.motion ?? []),
+      ...(options.flow ?? []),
+    ],
+    invariants: [
+      { type: "required", regions: [...(options.required ?? []), ...inferred] },
+      ...(options.continuousAny ?? []).map(
+        (regions): VisualInvariant<RegionName> => ({ type: "continuous-any", regions }),
+      ),
+      ...(options.unique ? [{ type: "unique" as const, regions: options.unique }] : []),
+      ...(options.stable ? [{ type: "stable" as const, regions: options.stable }] : []),
+      ...(options.fixed
+        ? [{ type: "fixed" as const, regions: options.fixed, tolerance: options.motionTolerance }]
+        : []),
+      { type: "opacity", regions: "all", floor: options.opacityFloor },
+      { type: "continuity", regions: "all" },
+      {
+        type: "motion",
+        regions: options.motion ?? "all",
+        tolerance: options.motionTolerance,
+        maxReversals: options.maxReversals,
+        maxPositionReversals: options.maxPositionReversals,
+      },
+      { type: "label-stability", regions: "all" },
+      ...(options.preserveBottomAnchor ? [{ type: "preserve-bottom-anchor" as const }] : []),
+      ...(options.acquireBottomAnchor ? [{ type: "acquire-bottom-anchor" as const }] : []),
+      ...(options.flow
+        ? [{ type: "flow" as const, regions: options.flow, overlapTolerance: options.overlapTolerance }]
+        : []),
+    ],
+  }
+}

packages/app/e2e/utils/visual-stability/model.ts

@@ -0,0 +1,47 @@
+export type VisualRegionSample = {
+  present: boolean
+  visible: boolean
+  inViewport: boolean
+  cssHidden?: boolean
+  top: number
+  bottom: number
+  layoutTop?: number
+  layoutBottom?: number
+  width: number
+  height: number
+  opacity: number
+  count: number
+  node: number
+  label: string
+  text: string
+}
+
+export type VisualViewportSample = {
+  top: number
+  bottom: number
+  scrollTop: number
+  scrollHeight: number
+  clientHeight: number
+  distanceFromBottom: number
+}
+
+export type VisualObservation<RegionName extends string = string> = {
+  at: number
+  regions: string extends RegionName
+    ? Record<string, VisualRegionSample>
+    : Partial<Record<RegionName, VisualRegionSample>>
+  viewport?: VisualViewportSample
+}
+
+export type VisualMarker = { at: number; label: string }
+
+export type VisualStabilityTrace<RegionName extends string = string> = {
+  markers: VisualMarker[]
+  samples: VisualObservation<RegionName>[]
+}
+
+export type CapturedFrame = { at: number; data: string }
+
+export type VisualProbeResult<RegionName extends string = string> = VisualStabilityTrace<RegionName> & {
+  frames: CapturedFrame[]
+}

packages/app/e2e/utils/visual-stability/probe.ts

@@ -0,0 +1,226 @@
+import type { Page } from "@playwright/test"
+import { startVisualCapture, stopVisualCapture, type VisualCapture } from "./capture"
+import type { VisualMarker, VisualObservation, VisualProbeResult } from "./model"
+import type { VisualRegionDefinition } from "./regions"
+
+type ProbeWindow<RegionName extends string = string> = Window & {
+  __visualStabilityProbe?: {
+    startedAt: number
+    markers: VisualMarker[]
+    samples: VisualObservation<RegionName>[]
+    stop: () => void
+  }
+}
+
+const captures = new WeakMap<Page, VisualCapture>()
+
+export async function startVisualProbe<Regions extends Record<string, VisualRegionDefinition>>(
+  page: Page,
+  regions: Regions,
+) {
+  await stopCapture(page)
+  await page.evaluate(() => {
+    ;(window as ProbeWindow).__visualStabilityProbe?.stop()
+  })
+  const startedAtEpoch = await page.evaluate((regions) => {
+    const samples: VisualObservation[] = []
+    const markers: VisualMarker[] = []
+    const startedAt = performance.now()
+    const nodes = new WeakMap<Node, number>()
+    const lastBounds = new Map<string, { top: number; bottom: number }>()
+    let nextNode = 1
+    let running = true
+    const round = (value: number) => Math.round(value * 10) / 10
+    const opacity = (element: Element) => Number(getComputedStyle(element).opacity)
+    const sample = () => {
+      if (!running) return
+      setTimeout(() => {
+        if (!running) return
+        const viewport = [...document.querySelectorAll<HTMLElement>(".scroll-view__viewport")].find((element) =>
+          element.querySelector("[data-timeline-row]"),
+        )
+        const viewportRect = viewport?.getBoundingClientRect()
+        samples.push({
+          at: performance.now() - startedAt,
+          viewport: viewport
+            ? {
+                top: round(viewportRect!.top),
+                bottom: round(viewportRect!.bottom),
+                scrollTop: round(viewport.scrollTop),
+                scrollHeight: round(viewport.scrollHeight),
+                clientHeight: round(viewport.clientHeight),
+                distanceFromBottom: round(viewport.scrollHeight - viewport.clientHeight - viewport.scrollTop),
+              }
+            : undefined,
+          regions: Object.fromEntries(
+            Object.entries(regions).map(([name, config]) => {
+              const found = document.querySelector<HTMLElement>(config.selector)
+              const count = document.querySelectorAll(config.selector).length
+              const element = config.closest ? found?.closest<HTMLElement>(config.closest) : found
+              if (!element)
+                return [
+                  name,
+                  {
+                    present: false,
+                    visible: false,
+                    inViewport: false,
+                    top: 0,
+                    bottom: 0,
+                    width: 0,
+                    height: 0,
+                    opacity: 0,
+                    count,
+                    node: 0,
+                    label: "",
+                    text: "",
+                  },
+                ]
+              const rect = element.getBoundingClientRect()
+              const style = getComputedStyle(element)
+              if (rect.height > 0) lastBounds.set(name, { top: rect.top, bottom: rect.bottom })
+              const known = rect.height > 0 ? rect : lastBounds.get(name)
+              const painted = (() => {
+                const result = { top: rect.top, bottom: rect.bottom, left: rect.left, right: rect.right }
+                let parent = element.parentElement
+                while (parent) {
+                  const parentStyle = getComputedStyle(parent)
+                  if (["hidden", "clip", "scroll", "auto"].includes(parentStyle.overflowY)) {
+                    const parentRect = parent.getBoundingClientRect()
+                    result.top = Math.max(result.top, parentRect.top)
+                    result.bottom = Math.min(result.bottom, parentRect.bottom)
+                  }
+                  if (["hidden", "clip", "scroll", "auto"].includes(parentStyle.overflowX)) {
+                    const parentRect = parent.getBoundingClientRect()
+                    result.left = Math.max(result.left, parentRect.left)
+                    result.right = Math.min(result.right, parentRect.right)
+                  }
+                  if (parent === viewport) break
+                  parent = parent.parentElement
+                }
+                if (viewportRect) {
+                  result.top = Math.max(result.top, viewportRect.top)
+                  result.bottom = Math.min(result.bottom, viewportRect.bottom)
+                  result.left = Math.max(result.left, viewportRect.left)
+                  result.right = Math.min(result.right, viewportRect.right)
+                }
+                return result
+              })()
+              const contentOpacity = config.opacitySelectors?.length
+                ? Math.max(
+                    0,
+                    ...config.opacitySelectors.flatMap((selector) =>
+                      [...element.querySelectorAll(selector)].map((node) => {
+                        let value = 1
+                        let current: Element | null = node
+                        while (current) {
+                          value *= opacity(current)
+                          if (current === element) break
+                          current = current.parentElement
+                        }
+                        return value
+                      }),
+                    ),
+                  )
+                : opacity(element)
+              let visibleOpacity = contentOpacity
+              let ancestor = element.parentElement
+              let ancestorHidden = false
+              while (ancestor) {
+                const ancestorStyle = getComputedStyle(ancestor)
+                visibleOpacity *= Number(ancestorStyle.opacity)
+                if (ancestorStyle.display === "none" || ancestorStyle.visibility === "hidden") ancestorHidden = true
+                if (ancestor === viewport) break
+                ancestor = ancestor.parentElement
+              }
+              const cssHidden =
+                ancestorHidden || style.display === "none" || style.visibility === "hidden" || visibleOpacity === 0
+              return [
+                name,
+                {
+                  present: true,
+                  visible:
+                    style.display !== "none" &&
+                    style.visibility !== "hidden" &&
+                    visibleOpacity > 0 &&
+                    painted.right > painted.left &&
+                    painted.bottom > painted.top,
+                  inViewport:
+                    !viewportRect || (!!known && known.bottom > viewportRect.top && known.top < viewportRect.bottom),
+                  cssHidden,
+                  top: round(painted.top),
+                  bottom: round(painted.bottom),
+                  layoutTop: round(rect.top),
+                  layoutBottom: round(rect.bottom),
+                  width: round(painted.right - painted.left),
+                  height: round(painted.bottom - painted.top),
+                  opacity: round(visibleOpacity),
+                  count,
+                  node: (() => {
+                    const current = nodes.get(element)
+                    if (current) return current
+                    nodes.set(element, nextNode)
+                    return nextNode++
+                  })(),
+                  label: element.getAttribute("aria-label") ?? "",
+                  text: (element.textContent ?? "").trim().replace(/\s+/g, " ").slice(0, 500),
+                },
+              ]
+            }),
+          ),
+        })
+        requestAnimationFrame(sample)
+      }, 0)
+    }
+    ;(window as ProbeWindow).__visualStabilityProbe = {
+      startedAt,
+      markers,
+      samples,
+      stop: () => {
+        running = false
+      },
+    }
+    requestAnimationFrame(sample)
+    return new Promise<number>((resolve) => {
+      const ready = () => {
+        if (samples.length > 0) return resolve(performance.timeOrigin + startedAt)
+        requestAnimationFrame(ready)
+      }
+      ready()
+    })
+  }, regions)
+  const capture = await startVisualCapture(page, startedAtEpoch)
+  if (capture) captures.set(page, capture)
+}
+
+export async function stopVisualProbe<RegionName extends string = string>(
+  page: Page,
+): Promise<VisualProbeResult<RegionName>> {
+  return page
+    .evaluate(() => {
+      const probe = (window as ProbeWindow).__visualStabilityProbe
+      if (!probe) throw new Error("Visual stability probe is not running")
+      probe.stop()
+      return { markers: probe.markers, samples: probe.samples }
+    })
+    .then(
+      async (trace) => ({ ...trace, frames: await stopCapture(page) }) as unknown as VisualProbeResult<RegionName>,
+      async (error: unknown) => {
+        await stopCapture(page)
+        throw error
+      },
+    )
+}
+
+export async function markVisualProbe(page: Page, label: string) {
+  await page.evaluate((label) => {
+    const probe = (window as ProbeWindow).__visualStabilityProbe
+    if (!probe) return
+    probe.markers.push({ at: performance.now() - probe.startedAt, label })
+  }, label)
+}
+
+async function stopCapture(page: Page) {
+  const capture = captures.get(page)
+  if (capture) captures.delete(page)
+  return stopVisualCapture(capture)
+}

packages/app/e2e/utils/visual-stability/regions.ts

@@ -0,0 +1,18 @@
+export type VisualRegionDefinition = {
+  selector: string
+  closest?: string
+  opacitySelectors?: readonly string[]
+}
+
+export function defineVisualRegions<const Regions extends Record<string, VisualRegionDefinition>>(regions: Regions) {
+  return regions
+}
+
+export function mapVisualRegions<const Regions extends Record<string, VisualRegionDefinition>, Result>(
+  regions: Regions,
+  map: (region: Regions[keyof Regions], name: keyof Regions) => Result,
+) {
+  return Object.fromEntries(
+    Object.entries(regions).map(([name, region]) => [name, map(region as Regions[keyof Regions], name)]),
+  ) as { [Name in keyof Regions]: Result }
+}

packages/app/e2e/utils/visual-stability/reporter.ts

@@ -0,0 +1,63 @@
+import { expect, type TestInfo } from "@playwright/test"
+import { writeFile } from "node:fs/promises"
+import { analyzeVisualObservations, analyzeVisualTraceByMarker } from "./analyzer"
+import type { VisualPlan } from "./invariant"
+import type { VisualProbeResult } from "./model"
+
+export async function reportVisualStability<RegionName extends string>(
+  testInfo: TestInfo,
+  name: string,
+  result: VisualProbeResult<RegionName>,
+  plan: VisualPlan<RegionName>,
+) {
+  const trace = { markers: result.markers, samples: result.samples }
+  const issues = plan.perMarker
+    ? analyzeVisualTraceByMarker(trace, plan)
+    : analyzeVisualObservations(result.samples, plan)
+  const tracePath = testInfo.outputPath(`${name}-visual-trace.json`)
+  const issuesPath = testInfo.outputPath(`${name}-visual-issues.json`)
+  await writeFile(tracePath, JSON.stringify(trace, null, 2))
+  await writeFile(
+    issuesPath,
+    JSON.stringify({ issues, markers: result.markers, capturedFrameCount: result.frames.length }, null, 2),
+  )
+  await testInfo.attach(`${name}-visual-trace`, { path: tracePath, contentType: "application/json" })
+  await testInfo.attach(`${name}-visual-issues`, { path: issuesPath, contentType: "application/json" })
+  if (issues.length) await attachViolationFrames(testInfo, name, result, issues)
+  expect(issues, `${name}: ${issues.join("\n")}`).toEqual([])
+}
+
+async function attachViolationFrames<RegionName extends string>(
+  testInfo: TestInfo,
+  name: string,
+  result: VisualProbeResult<RegionName>,
+  issues: string[],
+) {
+  if (result.frames.length === 0) return
+  const targets = [
+    ...new Set(
+      issues.flatMap((issue) => {
+        const match = issue.match(/ at (\d+)ms/)
+        if (match) return [Number(match[1])]
+        const marker = result.markers.find((item) => issue.startsWith(`${item.label}:`))
+        return marker ? [marker.at] : []
+      }),
+    ),
+  ].slice(0, 6)
+  for (const [violation, target] of targets.entries()) {
+    const nearest = result.frames.reduce(
+      (best, frame, index) => (Math.abs(frame.at - target) < Math.abs(result.frames[best]!.at - target) ? index : best),
+      0,
+    )
+    for (const [label, index] of [
+      ["before", Math.max(0, nearest - 1)],
+      ["violation", nearest],
+      ["after", Math.min(result.frames.length - 1, nearest + 1)],
+    ] as const) {
+      await testInfo.attach(`${name}-${violation + 1}-${label}-${Math.round(result.frames[index]!.at)}ms`, {
+        body: Buffer.from(result.frames[index]!.data, "base64"),
+        contentType: "image/jpeg",
+      })
+    }
+  }
+}

packages/app/e2e/utils/visual-stability/scenario.ts

@@ -0,0 +1,20 @@
+import type { Page, TestInfo } from "@playwright/test"
+import type { VisualPlan } from "./invariant"
+import { startVisualProbe, stopVisualProbe } from "./probe"
+import type { VisualRegionDefinition } from "./regions"
+import { reportVisualStability } from "./reporter"
+
+export async function runVisualStabilityScenario<const Regions extends Record<string, VisualRegionDefinition>>(input: {
+  page: Page
+  testInfo: TestInfo
+  name: string
+  regions: Regions
+  plan: VisualPlan<Extract<keyof Regions, string>>
+  run: () => Promise<void>
+}) {
+  await startVisualProbe(input.page, input.regions)
+  await input.run()
+  const result = await stopVisualProbe<Extract<keyof Regions, string>>(input.page)
+  await reportVisualStability(input.testInfo, input.name, result, input.plan)
+  return result
+}

packages/app/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@opencode-ai/app",
-  "version": "1.17.11",
+  "version": "1.17.14",
   "description": "",
   "type": "module",
   "exports": {
@@ -13,6 +13,7 @@
   },
   "scripts": {
     "typecheck": "tsgo -b",
+    "typecheck:e2e": "tsgo -p e2e/tsconfig.json",
     "start": "vite",
     "dev": "vite",
     "build": "vite build",
@@ -25,6 +26,7 @@
     "test:e2e:local": "playwright test",
     "test:e2e:ui": "playwright test --ui",
     "test:e2e:report": "playwright show-report e2e/playwright-report",
+    "test:stability": "bun test ./e2e/performance/unit/visual-stability.test.ts && playwright test --config e2e/performance/timeline-stability/playwright.config.ts",
     "test:bench": "bun test ./e2e/performance/unit && playwright test --config e2e/performance/playwright.config.ts"
   },
   "license": "MIT",
@@ -51,6 +53,7 @@
     "@dnd-kit/solid": "0.5.0",
     "@kobalte/core": "catalog:",
     "@opencode-ai/core": "workspace:*",
+    "@opencode-ai/schema": "workspace:*",
     "@opencode-ai/sdk": "workspace:*",
     "@opencode-ai/session-ui": "workspace:*",
     "@opencode-ai/ui": "workspace:*",

packages/app/src/app.tsx

@@ -28,22 +28,22 @@ import {
   Show,
 } from "solid-js"
 import { Dynamic } from "solid-js/web"
-import { CommandProvider } from "@/context/command"
+import { CommandProvider, useCommand, type CommandOption } from "@/context/command"
 import { CommentsProvider } from "@/context/comments"
 import { FileProvider } from "@/context/file"
-import { ServerSDKProvider, useServerSDK } from "@/context/server-sdk"
-import { ServerSyncProvider, useServerSync } from "@/context/server-sync"
+import { ServerSDKProvider } from "@/context/server-sdk"
+import { ServerSyncProvider } from "@/context/server-sync"
 import { GlobalProvider, useGlobal } from "@/context/global"
 import { HighlightsProvider } from "@/context/highlights"
 import { LanguageProvider, type Locale, useLanguage } from "@/context/language"
 import { LayoutProvider } from "@/context/layout"
 import { ModelsProvider } from "@/context/models"
-import { NotificationProvider, useNotification } from "@/context/notification"
+import { NotificationProvider } from "@/context/notification"
 import { PermissionProvider } from "@/context/permission"
+import { usePlatform } from "@/context/platform"
 import { PromptProvider } from "@/context/prompt"
 import { ServerConnection, ServerProvider, serverName, useServer } from "@/context/server"
 import { SettingsProvider, useSettings } from "@/context/settings"
-import { TerminalProvider } from "@/context/terminal"
 import { TabsProvider, useTabs, type DraftTab } from "@/context/tabs"
 import { SDKProvider, useSDK } from "@/context/sdk"
 import { WslServersProvider } from "@/wsl/context"
@@ -52,16 +52,9 @@ import LegacyLayout from "@/pages/layout"
 import NewLayout from "@/pages/layout-new"
 import { ErrorPage } from "./pages/error"
 import { useCheckServerHealth } from "./utils/server-health"
-import {
-  legacySessionHref,
-  legacySessionServer,
-  requireServerKey,
-  selectSessionLineage,
-  sessionHref,
-} from "./utils/session-route"
-import { isSessionNotFoundError } from "./utils/server-errors"
+import { legacySessionServer, requireServerKey, sessionHref } from "./utils/session-route"
 
-import Session from "@/pages/session"
+import { SessionPage, TargetSessionRouteContent } from "@/pages/session"
 import { NewHome, LegacyHome } from "@/pages/home"
 
 const NewSession = lazy(() => import("@/pages/new-session"))
@@ -95,11 +88,7 @@ const SessionRoute = () => {
     tabs.newDraft({ server: server.key, directory: sdk().directory }, search.prompt)
   })
 
-  return (
-    <SessionProviders>
-      <Session />
-    </SessionProviders>
-  )
+  return <SessionPage />
 }
 
 const TargetSessionRoute = () => {
@@ -111,79 +100,19 @@ const TargetSessionRoute = () => {
   })
 
   return (
+    // Owns the server-identity remount. Session changes must NOT remount this
+    // subtree (SessionRouteErrorBoundary resets and createSessionLineage
+    // re-resolves reactively instead); both rely on this key for server changes.
     <Show when={requireServerKey(params.serverKey)} keyed>
       <ServerSDKProvider server={conn}>
         <ServerSyncProvider server={conn}>
-          <ResolvedTargetSessionRoute />
+          <TargetSessionRouteContent />
         </ServerSyncProvider>
       </ServerSDKProvider>
     </Show>
   )
 }
 
-function ResolvedTargetSessionRoute() {
-  const params = useParams<{ serverKey: string; id: string }>()
-  const settings = useSettings()
-  const tabs = useTabs()
-  const sync = useServerSync()
-  const serverKey = createMemo(() => requireServerKey(params.serverKey))
-  const cached = createMemo(() => sync().session.lineage.peek(params.id))
-  const [resolved] = createResource(
-    () => {
-      if (cached()) return
-      return { id: params.id, server: serverKey(), sync: sync() }
-    },
-    ({ id, server, sync }) =>
-      sync.session.lineage.resolve(id).catch((error) => {
-        if (isSessionNotFoundError(error, id)) tabs.removeSessionTab({ server, sessionId: id })
-        throw error
-      }),
-  )
-  const current = createMemo(() => selectSessionLineage(params.id, cached(), resolved()))
-  const directory = createMemo(() => current()?.session.directory)
-  const targetDirectory = () => directory()!
-
-  createEffect(() => {
-    const session = current()
-    if (!session) return
-    tabs.addSessionTab({
-      server: serverKey(),
-      sessionId: session.root.id,
-    })
-  })
-
-  return (
-    <TargetServerScopedProviders directory={directory} sessionID={() => params.id}>
-      <Show when={!!current() || resolved.state !== "errored"} fallback={<ErrorPage error={resolved.error} />}>
-        <Show when={directory()}>
-          <Show
-            when={settings.general.newLayoutDesigns()}
-            fallback={<Navigate href={legacySessionHref(directory()!, params.id)} />}
-          >
-            <SDKProvider directory={targetDirectory}>
-              <DirectoryDataProvider directory={targetDirectory} server={serverKey}>
-                <TargetSessionPage />
-              </DirectoryDataProvider>
-            </SDKProvider>
-          </Show>
-        </Show>
-      </Show>
-    </TargetServerScopedProviders>
-  )
-}
-
-function TargetSessionPage() {
-  const sdk = useSDK()
-  const serverSDK = useServerSDK()
-  return (
-    <Show when={`${serverSDK().scope}\0${sdk().directory}`} keyed>
-      <SessionProviders>
-        <Session />
-      </SessionProviders>
-    </Show>
-  )
-}
-
 // Wraps the non-draft routes. They are gated on (and keyed to) the globally selected
 // server via ServerKey, then provide the server-scoped shell (Permission/Layout/
 // Notification/Models + the visual Layout) for that server.
@@ -197,10 +126,10 @@ function SelectedServerProviders(props: ParentProps) {
   )
 }
 
-function LegacyServerLayout(props: ParentProps) {
+function LegacyServerLayout(props: ParentProps<{ serverScoped?: JSX.Element }>) {
   return (
     <SelectedServerProviders>
-      <LegacyServerScopedShell>{props.children}</LegacyServerScopedShell>
+      <LegacyServerScopedShell serverScoped={props.serverScoped}>{props.children}</LegacyServerScopedShell>
     </SelectedServerProviders>
   )
 }
@@ -231,7 +160,7 @@ function ResolvedDraftRoute(props: { draft: DraftTab }) {
     <Show when={`${props.draft.server}\0${props.draft.directory}`} keyed>
       <ServerSDKProvider server={conn}>
         <ServerSyncProvider server={conn}>
-          <TargetServerScopedProviders directory={directory}>
+          <DraftServerScopedProviders directory={directory}>
             <SDKProvider directory={directory}>
               <DirectoryDataProvider directory={directory} server={serverKey}>
                 <DraftProviders>
@@ -239,7 +168,7 @@ function ResolvedDraftRoute(props: { draft: DraftTab }) {
                 </DraftProviders>
               </DirectoryDataProvider>
             </SDKProvider>
-          </TargetServerScopedProviders>
+          </DraftServerScopedProviders>
         </ServerSyncProvider>
       </ServerSDKProvider>
     </Show>
@@ -257,7 +186,7 @@ declare global {
       deepLinks?: string[]
     }
     api?: {
-      setTitlebar?: (theme: { mode: "light" | "dark" }) => Promise<void>
+      setTitlebar?: (theme: { mode: "light" | "dark"; scheme?: "system" | "light" | "dark" }) => Promise<void>
       exportDebugLogs?: () => Promise<string>
     }
   }
@@ -300,22 +229,48 @@ function SharedProviders(props: ParentProps) {
     <>
       <BodyDesignClass />
       <CommandProvider>
+        <DesktopCommands />
         <HighlightsProvider>{props.children}</HighlightsProvider>
       </CommandProvider>
     </>
   )
 }
 
+function DesktopCommands() {
+  const command = useCommand()
+  const language = useLanguage()
+  const platform = usePlatform()
+
+  command.register("desktop", () => {
+    const commands: CommandOption[] = []
+    if (platform.platform === "desktop" && platform.exportDebugLogs) {
+      commands.push({
+        id: "logs.export",
+        title: "Export logs",
+        category: language.t("command.category.settings"),
+        onSelect: () => {
+          void platform.exportDebugLogs?.()
+        },
+      })
+    }
+    return commands
+  })
+
+  return null
+}
+
 // Server-scoped providers shared by the legacy shell and the top-level new shell.
 type ServerScopedShellProps = ParentProps<{
   directory?: () => string | undefined
   sessionID?: () => string | undefined
+  serverScoped?: JSX.Element
 }>
 
 function ServerScopedProviders(props: ServerScopedShellProps) {
   return (
     <PermissionProvider directory={props.directory}>
       <LayoutProvider>
+        {props.serverScoped}
         <ModelsProvider directory={props.directory}>{props.children}</ModelsProvider>
       </LayoutProvider>
     </PermissionProvider>
@@ -324,54 +279,30 @@ function ServerScopedProviders(props: ServerScopedShellProps) {
 
 function LegacyServerScopedShell(props: ServerScopedShellProps) {
   return (
-    <ServerScopedProviders directory={props.directory} sessionID={props.sessionID}>
+    <ServerScopedProviders directory={props.directory} sessionID={props.sessionID} serverScoped={props.serverScoped}>
       <LegacyLayout>{props.children}</LegacyLayout>
     </ServerScopedProviders>
   )
 }
 
-function NewAppLayout(props: ParentProps) {
+function NewAppLayout(props: ParentProps<{ serverScoped?: JSX.Element }>) {
   return (
     <SelectedServerProviders>
-      <ServerScopedProviders>
+      <ServerScopedProviders serverScoped={props.serverScoped}>
         <NewLayout>{props.children}</NewLayout>
       </ServerScopedProviders>
     </SelectedServerProviders>
   )
 }
 
-function TargetServerScopedProviders(props: ServerScopedShellProps) {
+function DraftServerScopedProviders(props: ParentProps<{ directory?: () => string | undefined }>) {
   return (
     <PermissionProvider directory={props.directory}>
-      <MarkSessionNotificationsViewed sessionID={props.sessionID} />
       <ModelsProvider directory={props.directory}>{props.children}</ModelsProvider>
     </PermissionProvider>
   )
 }
 
-function MarkSessionNotificationsViewed(props: { sessionID?: () => string | undefined }) {
-  const notification = useNotification()
-  createEffect(() => {
-    const sessionID = props.sessionID?.()
-    if (!notification.ready() || !sessionID) return
-    if (notification.session.unseenCount(sessionID) === 0) return
-    notification.session.markViewed(sessionID)
-  })
-  return null
-}
-
-function SessionProviders(props: ParentProps) {
-  return (
-    <TerminalProvider>
-      <FileProvider>
-        <PromptProvider>
-          <CommentsProvider>{props.children}</CommentsProvider>
-        </PromptProvider>
-      </FileProvider>
-    </TerminalProvider>
-  )
-}
-
 // The draft page only renders the prompt composer, so it drops TerminalProvider.
 // FileProvider and CommentsProvider stay because PromptInput uses file search and comment context.
 function DraftProviders(props: ParentProps) {
@@ -389,8 +320,8 @@ export function AppBaseProviders(props: ParentProps<{ locale?: Locale }>) {
     <MetaProvider>
       <Font />
       <ThemeProvider
-        onThemeApplied={(_, mode) => {
-          void window.api?.setTitlebar?.({ mode })
+        onThemeApplied={(_, mode, scheme) => {
+          void window.api?.setTitlebar?.({ mode, scheme })
         }}
       >
         <LanguageProvider locale={props.locale}>
@@ -418,7 +349,7 @@ export function AppBaseProviders(props: ParentProps<{ locale?: Locale }>) {
   )
 }
 
-function ConnectionGate(props: ParentProps<{ disableHealthCheck?: boolean }>) {
+function ConnectionGate(props: ParentProps<{ disableHealthCheck?: boolean; startup?: Promise<void> }>) {
   const server = useServer()
   const checkServerHealth = useCheckServerHealth()
 
@@ -447,34 +378,45 @@ function ConnectionGate(props: ParentProps<{ disableHealthCheck?: boolean }>) {
   const checking = createMemo(
     () => checkMode() === "blocking" && ["unresolved", "pending"].includes(startupHealthCheck.state),
   )
+  const [startup] = createResource(async () => {
+    if (!props.startup) return true
+    await props.startup.catch((error) => {
+      console.error("[startup] startup gate failed", error)
+    })
+    return true
+  })
+  const startupChecking = createMemo(
+    () => startupHealthCheck.latest === true && ["unresolved", "pending"].includes(startup.state),
+  )
+  const loading = createMemo(() => checking() || startupChecking())
 
   return (
-    <Show
-      when={!checking()}
-      fallback={
-        <div class="h-dvh w-screen flex flex-col items-center justify-center bg-background-base">
+    <>
+      <Show when={!checking()}>
+        <Show
+          when={startupHealthCheck.latest}
+          fallback={
+            <ConnectionError
+              onRetry={() => {
+                if (checkMode() === "background") void healthCheckActions.refetch()
+              }}
+              onServerSelected={(key) => {
+                setCheckMode("blocking")
+                server.setActive(key)
+                void healthCheckActions.refetch()
+              }}
+            />
+          }
+        >
+          {props.children}
+        </Show>
+      </Show>
+      <Show when={loading()}>
+        <div class="fixed inset-0 z-[9999] flex flex-col items-center justify-center bg-background-base">
           <Splash class="w-16 h-20 opacity-50 animate-pulse" />
         </div>
-      }
-    >
-      <Show
-        when={startupHealthCheck.latest}
-        fallback={
-          <ConnectionError
-            onRetry={() => {
-              if (checkMode() === "background") void healthCheckActions.refetch()
-            }}
-            onServerSelected={(key) => {
-              setCheckMode("blocking")
-              server.setActive(key)
-              void healthCheckActions.refetch()
-            }}
-          />
-        }
-      >
-        {props.children}
       </Show>
-    </Show>
+    </>
   )
 }
 
@@ -541,6 +483,8 @@ export function AppInterface(props: {
   servers?: Array<ServerConnection.Any>
   router?: Component<BaseRouterProps>
   disableHealthCheck?: boolean
+  startup?: Promise<void>
+  serverScoped?: JSX.Element
 }) {
   // The visual new layout lives in the router root so it remains mounted across
   // route changes. Draft and session routes override only their server-bound data
@@ -562,7 +506,7 @@ export function AppInterface(props: {
     >
       <GlobalProvider>
         <SettingsProvider>
-          <ConnectionGate disableHealthCheck={props.disableHealthCheck}>
+          <ConnectionGate disableHealthCheck={props.disableHealthCheck} startup={props.startup}>
             <Show when={useSettings().general.newLayoutDesigns().toString()} keyed>
               <Dynamic
                 component={props.router ?? Router}
@@ -571,14 +515,14 @@ export function AppInterface(props: {
                     <NotificationProvider>
                       <ServerShell>
                         <Show when={useSettings().general.newLayoutDesigns()} fallback={routerProps.children}>
-                          <NewAppLayout>{routerProps.children}</NewAppLayout>
+                          <NewAppLayout serverScoped={props.serverScoped}>{routerProps.children}</NewAppLayout>
                         </Show>
                       </ServerShell>
                     </NotificationProvider>
                   </TabsProvider>
                 )}
               >
-                <Routes />
+                <Routes serverScoped={props.serverScoped} />
               </Dynamic>
             </Show>
           </ConnectionGate>
@@ -588,12 +532,16 @@ export function AppInterface(props: {
   )
 }
 
-function Routes() {
+function Routes(props: { serverScoped?: JSX.Element }) {
   const settings = useSettings()
 
   return (
     <>
-      <Route component={LegacyServerLayout}>
+      <Route
+        component={(routeProps) => (
+          <LegacyServerLayout serverScoped={props.serverScoped}>{routeProps.children}</LegacyServerLayout>
+        )}
+      >
         <Show when={!settings.general.newLayoutDesigns()}>{<Route path="/" component={LegacyHome} />}</Show>
         <Route path="/:dir" component={DirectoryLayout}>
           <Route path="/" component={() => <Navigate href="session" />} />

packages/app/src/components/command-palette.ts

@@ -0,0 +1,325 @@
+import { base64Encode } from "@opencode-ai/core/util/encode"
+import { getFilename } from "@opencode-ai/core/util/path"
+import { useDialog } from "@opencode-ai/ui/context/dialog"
+import { useNavigate } from "@solidjs/router"
+import { createMemo, onCleanup } from "solid-js"
+import { useCommand, type CommandOption } from "@/context/command"
+import { useFile } from "@/context/file"
+import { useLanguage } from "@/context/language"
+import { useLayout } from "@/context/layout"
+import { useServerSDK, type ServerSDK } from "@/context/server-sdk"
+import { useServerSync } from "@/context/server-sync"
+import { createSessionTabs } from "@/pages/session/helpers"
+import { useSessionLayout } from "@/pages/session/session-layout"
+import { decode64 } from "@/utils/base64"
+
+export type CommandPaletteEntry = {
+  id: string
+  type: "command" | "file" | "session"
+  title: string
+  description?: string
+  keybind?: string
+  category: string
+  option?: CommandOption
+  path?: string
+  directory?: string
+  sessionID?: string
+  archived?: number
+  updated?: number
+}
+
+const ENTRY_LIMIT = 5
+const COMMON_COMMAND_IDS = [
+  "session.new",
+  "workspace.new",
+  "session.previous",
+  "session.next",
+  "terminal.toggle",
+  "review.toggle",
+] as const
+
+export function uniqueCommandPaletteEntries(items: CommandPaletteEntry[]) {
+  const seen = new Set<string>()
+  return items.filter((item) => {
+    if (seen.has(item.id)) return false
+    seen.add(item.id)
+    return true
+  })
+}
+
+export function createCommandPaletteFileEntry(path: string, category: string): CommandPaletteEntry {
+  return {
+    id: "file:" + path,
+    type: "file",
+    title: path,
+    category,
+    path,
+  }
+}
+
+export function createCommandPaletteFileOpener(onOpenFile?: (path: string) => void) {
+  const file = useFile()
+  const layout = useLayout()
+  const { tabs, view } = useSessionLayout()
+
+  return (path: string) => {
+    const value = file.tab(path)
+    void tabs().open(value)
+    void file.load(path)
+    if (!view().reviewPanel.opened()) view().reviewPanel.open()
+    layout.fileTree.setTab("all")
+    onOpenFile?.(path)
+    tabs().setActive(value)
+  }
+}
+
+export function createCommandPaletteModel(props: { filesOnly?: () => boolean; onOpenFile?: (path: string) => void }) {
+  const command = useCommand()
+  const language = useLanguage()
+  const layout = useLayout()
+  const file = useFile()
+  const dialog = useDialog()
+  const navigate = useNavigate()
+  const serverSDK = useServerSDK()()
+  const serverSync = useServerSync()
+  const { params, tabs } = useSessionLayout()
+  const openFile = createCommandPaletteFileOpener(props.onOpenFile)
+  const state = { cleanup: undefined as (() => void) | void, committed: false }
+  const filesOnly = () => props.filesOnly?.() ?? false
+
+  const allowedCommands = createMemo(() => {
+    if (filesOnly()) return []
+    return command.options.filter(
+      (option) =>
+        !option.disabled && !option.hidden && !option.id.startsWith("suggested.") && option.id !== "file.open",
+    )
+  })
+  const commandEntries = createMemo(() => {
+    const category = language.t("palette.group.commands")
+    return allowedCommands().map((option) => createCommandEntry(option, category))
+  })
+  const preferredCommandEntries = createMemo(() => {
+    const all = allowedCommands()
+    const order = new Map<string, number>(COMMON_COMMAND_IDS.map((id, index) => [id, index]))
+    const picked = all.filter((option) => order.has(option.id))
+    const base = picked.length ? picked : all.slice(0, ENTRY_LIMIT)
+    const sorted = picked.length ? [...base].sort((a, b) => (order.get(a.id) ?? 0) - (order.get(b.id) ?? 0)) : base
+    const category = language.t("palette.group.commands")
+    return sorted.map((option) => createCommandEntry(option, category))
+  })
+
+  const tabState = createSessionTabs({
+    tabs,
+    pathFromTab: file.pathFromTab,
+    normalizeTab: (tab) => (tab.startsWith("file://") ? file.tab(tab) : tab),
+  })
+  const recentFileEntries = createMemo(() => {
+    const all = tabState.openedTabs()
+    const active = tabState.activeFileTab()
+    const order = active ? [active, ...all.filter((item) => item !== active)] : all
+    const seen = new Set<string>()
+    const category = language.t("palette.group.files")
+    return order
+      .map((item) => file.pathFromTab(item))
+      .filter((path): path is string => {
+        if (!path || seen.has(path)) return false
+        seen.add(path)
+        return true
+      })
+      .slice(0, ENTRY_LIMIT)
+      .map((path) => createCommandPaletteFileEntry(path, category))
+  })
+  const rootFileEntries = createMemo(() => {
+    const category = language.t("palette.group.files")
+    return file.tree
+      .children("")
+      .filter((node) => node.type === "file")
+      .map((node) => node.path)
+      .sort((a, b) => a.localeCompare(b))
+      .slice(0, ENTRY_LIMIT)
+      .map((path) => createCommandPaletteFileEntry(path, category))
+  })
+
+  const projectDirectory = createMemo(() => decode64(params.dir) ?? "")
+  const project = createMemo(() => {
+    const directory = projectDirectory()
+    if (!directory) return undefined
+    return layout.projects.list().find((item) => item.worktree === directory || item.sandboxes?.includes(directory))
+  })
+  const workspaces = createMemo(() => {
+    const directory = projectDirectory()
+    const current = project()
+    if (!current) return directory ? [directory] : []
+    const dirs = [current.worktree, ...(current.sandboxes ?? [])]
+    if (directory && !dirs.includes(directory)) return [...dirs, directory]
+    return dirs
+  })
+  const homedir = createMemo(() => serverSync().data.path.home)
+  const sessions = createSessionEntries({
+    workspaces,
+    label: (directory) => {
+      const current = project()
+      const kind =
+        current && directory === current.worktree
+          ? language.t("workspace.type.local")
+          : language.t("workspace.type.sandbox")
+      const [store] = serverSync().child(directory, { bootstrap: false })
+      const home = homedir()
+      const path = home ? directory.replace(home, "~") : directory
+      const name = store.vcs?.branch ?? getFilename(directory)
+      return `${kind} : ${name || path}`
+    },
+    load: (directory) => serverSDK.client.session.list({ directory, roots: true }),
+    untitled: () => language.t("command.session.new"),
+    category: () => language.t("command.category.session"),
+  })
+
+  const highlight = (item: CommandPaletteEntry | undefined) => {
+    state.cleanup?.()
+    state.cleanup = undefined
+    if (item?.type !== "command") return
+    state.cleanup = item.option?.onHighlight?.()
+  }
+
+  const select = (item: CommandPaletteEntry | undefined) => {
+    if (!item) return
+    state.committed = true
+    state.cleanup = undefined
+    dialog.close()
+    if (item.type === "command") {
+      item.option?.onSelect?.("palette")
+      return
+    }
+    if (item.type === "session") {
+      if (!item.directory || !item.sessionID) return
+      navigate(`/${base64Encode(item.directory)}/session/${item.sessionID}`)
+      return
+    }
+    if (!item.path) return
+    openFile(item.path)
+  }
+
+  onCleanup(() => {
+    if (state.committed) return
+    state.cleanup?.()
+  })
+
+  return {
+    language,
+    file,
+    commandEntries,
+    preferredCommandEntries,
+    recentFileEntries,
+    rootFileEntries,
+    sessions,
+    highlight,
+    select,
+    close: () => dialog.close(),
+  }
+}
+
+function createCommandEntry(option: CommandOption, category: string): CommandPaletteEntry {
+  return {
+    id: "command:" + option.id,
+    type: "command",
+    title: option.title,
+    description: option.description,
+    keybind: option.keybind,
+    category,
+    option,
+  }
+}
+
+function createSessionEntries(props: {
+  workspaces: () => string[]
+  label: (directory: string) => string
+  load: (directory: string) => ReturnType<ServerSDK["client"]["session"]["list"]>
+  untitled: () => string
+  category: () => string
+}) {
+  const state: {
+    token: number
+    inflight: Promise<CommandPaletteEntry[]> | undefined
+    cached: CommandPaletteEntry[] | undefined
+  } = { token: 0, inflight: undefined, cached: undefined }
+
+  return (text: string) => {
+    if (!text.trim()) {
+      state.token += 1
+      state.inflight = undefined
+      state.cached = undefined
+      return [] as CommandPaletteEntry[]
+    }
+    if (state.cached) return state.cached
+    if (state.inflight) return state.inflight
+
+    const current = state.token
+    const dirs = props.workspaces()
+    if (dirs.length === 0) return [] as CommandPaletteEntry[]
+
+    state.inflight = Promise.all(
+      dirs.map((directory) => {
+        const description = props.label(directory)
+        return props
+          .load(directory)
+          .then((result) =>
+            (result.data ?? [])
+              .filter((session) => !!session?.id)
+              .map((session) => ({
+                id: session.id,
+                title: session.title ?? props.untitled(),
+                description,
+                directory,
+                archived: session.time?.archived,
+                updated: session.time?.updated,
+              })),
+          )
+          .catch(() => [] as SessionEntryInput[])
+      }),
+    )
+      .then((results) => {
+        if (state.token !== current) return [] as CommandPaletteEntry[]
+        const seen = new Set<string>()
+        const next = results
+          .flat()
+          .filter((item) => {
+            const key = `${item.directory}:${item.id}`
+            if (seen.has(key)) return false
+            seen.add(key)
+            return true
+          })
+          .map((item) => createSessionEntry(item, props.category()))
+        state.cached = next
+        return next
+      })
+      .catch(() => [] as CommandPaletteEntry[])
+      .finally(() => {
+        state.inflight = undefined
+      })
+
+    return state.inflight
+  }
+}
+
+type SessionEntryInput = {
+  directory: string
+  id: string
+  title: string
+  description: string
+  archived?: number
+  updated?: number
+}
+
+function createSessionEntry(input: SessionEntryInput, category: string): CommandPaletteEntry {
+  return {
+    id: `session:${input.directory}:${input.id}`,
+    type: "session",
+    title: input.title,
+    description: input.description,
+    category,
+    directory: input.directory,
+    sessionID: input.id,
+    archived: input.archived,
+    updated: input.updated,
+  }
+}

packages/app/src/components/dialog-command-palette-v2.css

@@ -0,0 +1,220 @@
+.command-palette-v2 {
+  overflow: hidden;
+}
+
+/* Anchor to the top edge of where a centered 480px-tall dialog would sit, so the
+   top stays put while the content-driven height grows and shrinks. */
+[data-component="dialog-v2"]:has(.command-palette-v2) {
+  align-items: flex-start;
+}
+
+[data-component="dialog-v2"]:has(.command-palette-v2) [data-slot="dialog-container"] {
+  width: min(calc(100vw - 24px), 640px);
+  height: auto;
+  min-height: 280px;
+  max-height: min(calc(100vh - 96px), 480px);
+  margin-top: max(48px, calc((100vh - 480px) / 2));
+  border-radius: 12px;
+  background: var(--v2-background-bg-base);
+  box-shadow: var(--v2-elevation-floating);
+}
+
+.command-palette-v2-body {
+  display: flex;
+  min-height: 0;
+  flex: 1;
+  flex-direction: column;
+  gap: 0;
+  padding: 0;
+}
+
+.command-palette-v2-search {
+  flex-shrink: 0;
+  padding: 6px;
+}
+
+.command-palette-v2-search [data-component="text-input-v2"] {
+  width: 100%;
+  height: 36px;
+  border-radius: 6px;
+  outline: 0;
+  background: color-mix(in srgb, var(--v2-background-bg-layer-02) 60%, transparent);
+  box-shadow: none;
+  transition:
+    background-color 120ms ease-in-out,
+    box-shadow 120ms ease-in-out;
+}
+
+.command-palette-v2-search [data-component="text-input-v2"]:where(:hover):not([data-disabled], [data-invalid]),
+.command-palette-v2-search [data-component="text-input-v2"]:where(:focus-within):not([data-disabled], [data-invalid]) {
+  background: var(--v2-background-bg-layer-02);
+  box-shadow: none;
+}
+
+.command-palette-v2-search [data-component="text-input-v2"] [data-slot="text-input-v2-value"] {
+  border-radius: 6px;
+  background: transparent;
+  gap: 8px;
+}
+
+.command-palette-v2-search [data-component="text-input-v2"] [data-slot="text-input-v2-leading-icon"] {
+  padding-left: 12px;
+}
+
+.command-palette-v2-search [data-component="text-input-v2"] [data-slot="text-input-v2-input"] {
+  border-radius: 6px;
+  background: transparent;
+}
+
+.command-palette-v2-scroll {
+  min-height: 0;
+  flex: 1;
+}
+
+.command-palette-v2-results {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+  padding: 6px 6px 8px;
+}
+
+.command-palette-v2-group {
+  display: flex;
+  flex-direction: column;
+  gap: 1px;
+}
+
+.command-palette-v2-group-title {
+  margin: 6px 0;
+  padding: 0 12px;
+  color: var(--v2-text-text-muted);
+  font-size: 13px;
+  font-weight: 440;
+  line-height: 16px;
+  letter-spacing: -0.04px;
+  user-select: none;
+}
+
+.command-palette-v2-row {
+  display: flex;
+  width: 100%;
+  height: 36px;
+  flex-shrink: 0;
+  align-items: center;
+  justify-content: space-between;
+  gap: 8px;
+  padding: 0 12px;
+  border: 0;
+  border-radius: 6px;
+  background: transparent;
+  color: var(--v2-text-text-base);
+  text-align: left;
+  cursor: default;
+  scroll-margin: 6px 0;
+}
+
+.command-palette-v2-row[data-active] {
+  background: var(--v2-overlay-simple-overlay-hover);
+}
+
+.command-palette-v2-row:focus-visible {
+  background: var(--v2-overlay-simple-overlay-hover);
+  outline: none;
+}
+
+.command-palette-v2-row-main {
+  display: flex;
+  min-width: 0;
+  flex: 1;
+  align-items: center;
+  gap: 8px;
+}
+
+.command-palette-v2-row-icon {
+  flex-shrink: 0;
+  color: var(--v2-icon-icon-muted);
+}
+
+.command-palette-v2-row-text {
+  display: flex;
+  min-width: 0;
+  align-items: center;
+  gap: 6px;
+}
+
+.command-palette-v2-title {
+  min-width: 0;
+  overflow: hidden;
+  color: var(--v2-text-text-base);
+  font-size: 13px;
+  font-weight: 530;
+  line-height: 16px;
+  letter-spacing: -0.04px;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.command-palette-v2-description,
+.command-palette-v2-meta {
+  min-width: 0;
+  overflow: hidden;
+  color: var(--v2-text-text-muted);
+  font-size: 13px;
+  font-weight: 440;
+  line-height: 16px;
+  letter-spacing: -0.04px;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.command-palette-v2-meta {
+  flex-shrink: 0;
+}
+
+.command-palette-v2-file-path {
+  display: flex;
+  min-width: 0;
+  align-items: baseline;
+  font-size: 13px;
+  line-height: 16px;
+  letter-spacing: -0.04px;
+}
+
+.command-palette-v2-file-dir {
+  min-width: 0;
+  overflow: hidden;
+  color: var(--v2-text-text-muted);
+  font-weight: 440;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.command-palette-v2-file-name {
+  flex-shrink: 0;
+  color: var(--v2-text-text-base);
+  font-weight: 530;
+  white-space: nowrap;
+}
+
+.command-palette-v2-state {
+  display: grid;
+  min-height: 120px;
+  place-items: center;
+  color: var(--v2-text-text-muted);
+  font-size: 13px;
+  font-weight: 440;
+  line-height: 16px;
+  letter-spacing: -0.04px;
+}
+
+@media (max-width: 640px) {
+  .command-palette-v2-row-text {
+    flex-direction: column;
+    align-items: flex-start;
+    gap: 1px;
+  }
+
+  .command-palette-v2-description {
+    max-width: 100%;
+  }
+}

packages/app/src/components/dialog-command-palette-v2.tsx

@@ -0,0 +1,221 @@
+import { getDirectory, getFilename } from "@opencode-ai/core/util/path"
+import { FileIcon } from "@opencode-ai/ui/file-icon"
+import { ScrollView } from "@opencode-ai/ui/scroll-view"
+import { Dialog, DialogBody } from "@opencode-ai/ui/v2/dialog-v2"
+import { Icon } from "@opencode-ai/ui/v2/icon"
+import { KeybindV2 } from "@opencode-ai/ui/v2/keybind-v2"
+import { TextInputV2 } from "@opencode-ai/ui/v2/text-input-v2"
+import { createEffect, createMemo, createResource, createSignal, For, Match, Show, Switch } from "solid-js"
+import { formatKeybindParts } from "@/context/command"
+import { useLanguage } from "@/context/language"
+import { getRelativeTime } from "@/utils/time"
+import {
+  createCommandPaletteFileEntry,
+  createCommandPaletteModel,
+  uniqueCommandPaletteEntries,
+  type CommandPaletteEntry,
+} from "./command-palette"
+import "./dialog-command-palette-v2.css"
+
+function groups(entries: CommandPaletteEntry[]) {
+  const map = new Map<string, CommandPaletteEntry[]>()
+  for (const entry of entries) map.set(entry.category, [...(map.get(entry.category) ?? []), entry])
+  return Array.from(map.entries()).map(([category, entries]) => ({ category, entries }))
+}
+
+function matchesEntry(entry: CommandPaletteEntry, query: string) {
+  const value = query.toLowerCase()
+  return [entry.title, entry.description, entry.category].some((text) => text?.toLowerCase().includes(value))
+}
+
+export function DialogCommandPaletteV2(props: { onOpenFile?: (path: string) => void }) {
+  const palette = createCommandPaletteModel(props)
+  const [query, setQuery] = createSignal("")
+  const [active, setActive] = createSignal(0)
+
+  const loadItems = async (text: string) => {
+    const q = text.trim()
+    if (!q) return [...palette.preferredCommandEntries(), ...palette.recentFileEntries()]
+
+    const [files, nextSessions] = await Promise.all([palette.file.searchFiles(q), Promise.resolve(palette.sessions(q))])
+    const category = palette.language.t("palette.group.files")
+    return [
+      ...palette.commandEntries().filter((entry) => matchesEntry(entry, q)),
+      ...nextSessions.filter((entry) => matchesEntry(entry, q)),
+      ...files.map((path) => createCommandPaletteFileEntry(path, category)),
+    ]
+  }
+
+  const [entries] = createResource(query, loadItems, { initialValue: [] as CommandPaletteEntry[] })
+  // Render stale results while a new query loads to avoid flashing "Loading" per keystroke.
+  const visibleEntries = createMemo(() => uniqueCommandPaletteEntries(entries.latest ?? []))
+  const groupedEntries = createMemo(() => groups(visibleEntries()))
+  const activeEntry = createMemo(() => visibleEntries()[active()])
+
+  createEffect(() => {
+    query()
+    visibleEntries()
+    setActive(0)
+  })
+
+  createEffect(() => {
+    palette.highlight(activeEntry())
+  })
+
+  let resultsRef: HTMLDivElement | undefined
+
+  const move = (delta: -1 | 1) => {
+    const count = visibleEntries().length
+    if (count === 0) return
+    setActive((index) => (index + delta + count) % count)
+    requestAnimationFrame(() => {
+      resultsRef?.querySelector("[data-active]")?.scrollIntoView({ block: "nearest" })
+    })
+  }
+
+  const handleKeyDown = (event: KeyboardEvent) => {
+    if (event.key === "ArrowDown") {
+      event.preventDefault()
+      move(1)
+      return
+    }
+    if (event.key === "ArrowUp") {
+      event.preventDefault()
+      move(-1)
+      return
+    }
+    if (event.key === "Enter") {
+      event.preventDefault()
+      palette.select(activeEntry())
+      return
+    }
+    if (event.key === "Escape") {
+      event.preventDefault()
+      palette.close()
+    }
+  }
+
+  return (
+    <Dialog class="command-palette-v2" size="large">
+      <DialogBody class="command-palette-v2-body">
+        <div class="command-palette-v2-search">
+          <TextInputV2
+            value={query()}
+            autofocus
+            autocomplete="off"
+            spellcheck={false}
+            appearance="large"
+            placeholder={palette.language.t("palette.search.placeholder")}
+            leadingIcon={<Icon name="magnifying-glass" />}
+            onInput={(event) => setQuery(event.currentTarget.value)}
+            onKeyDown={handleKeyDown}
+          />
+        </div>
+        <ScrollView class="command-palette-v2-scroll" viewportRef={(el) => (resultsRef = el)}>
+          <div class="command-palette-v2-results" role="listbox">
+            <Show
+              when={visibleEntries().length > 0}
+              fallback={
+                <div class="command-palette-v2-state">
+                  {entries.loading ? palette.language.t("common.loading") : palette.language.t("palette.empty")}
+                </div>
+              }
+            >
+              <For each={groupedEntries()}>
+                {(group) => (
+                  <div class="command-palette-v2-group">
+                    <Show when={group.category}>
+                      <div class="command-palette-v2-group-title">{group.category}</div>
+                    </Show>
+                    <For each={group.entries}>
+                      {(item) => (
+                        <PaletteRow
+                          item={item}
+                          active={activeEntry()?.id === item.id}
+                          language={palette.language}
+                          onActive={() => setActive(visibleEntries().findIndex((entry) => entry.id === item.id))}
+                          onSelect={() => palette.select(item)}
+                        />
+                      )}
+                    </For>
+                  </div>
+                )}
+              </For>
+            </Show>
+          </div>
+        </ScrollView>
+      </DialogBody>
+    </Dialog>
+  )
+}
+
+function PaletteRow(props: {
+  item: CommandPaletteEntry
+  active: boolean
+  language: ReturnType<typeof useLanguage>
+  onActive: () => void
+  onSelect: () => void
+}) {
+  return (
+    <button
+      type="button"
+      class="command-palette-v2-row"
+      role="option"
+      aria-selected={props.active}
+      data-active={props.active ? "" : undefined}
+      onMouseMove={(event) => {
+        // Ignore hover from a static cursor when keyboard scrolling moves rows underneath it.
+        if (event.movementX === 0 && event.movementY === 0) return
+        props.onActive()
+      }}
+      onMouseDown={(event) => event.preventDefault()}
+      onClick={props.onSelect}
+    >
+      <Switch
+        fallback={
+          <div class="command-palette-v2-row-main">
+            <FileIcon node={{ path: props.item.path ?? "", type: "file" }} class="command-palette-v2-row-icon size-4" />
+            <div class="command-palette-v2-file-path">
+              <span class="command-palette-v2-file-dir">{getDirectory(props.item.path ?? "")}</span>
+              <span class="command-palette-v2-file-name">{getFilename(props.item.path ?? "")}</span>
+            </div>
+          </div>
+        }
+      >
+        <Match when={props.item.type === "command"}>
+          <div class="command-palette-v2-row-main">
+            <div class="command-palette-v2-row-text">
+              <span class="command-palette-v2-title">{props.item.title}</span>
+              <Show when={props.item.description}>
+                <span class="command-palette-v2-description">{props.item.description}</span>
+              </Show>
+            </div>
+          </div>
+          <Show when={props.item.keybind}>
+            <KeybindV2 keys={formatKeybindParts(props.item.keybind ?? "", props.language.t)} variant="neutral" />
+          </Show>
+        </Match>
+        <Match when={props.item.type === "session"}>
+          <div class="command-palette-v2-row-main">
+            <Icon name="status" class="command-palette-v2-row-icon" />
+            <div class="command-palette-v2-row-text">
+              <span class="command-palette-v2-title" classList={{ "opacity-70": !!props.item.archived }}>
+                {props.item.title}
+              </span>
+              <Show when={props.item.description}>
+                <span class="command-palette-v2-description" classList={{ "opacity-70": !!props.item.archived }}>
+                  {props.item.description}
+                </span>
+              </Show>
+            </div>
+          </div>
+          <Show when={props.item.updated}>
+            <span class="command-palette-v2-meta">
+              {getRelativeTime(new Date(props.item.updated!).toISOString(), props.language.t)}
+            </span>
+          </Show>
+        </Match>
+      </Switch>
+    </button>
+  )
+}

packages/app/src/components/dialog-connect-provider.tsx

@@ -7,29 +7,174 @@ import { IconButton } from "@opencode-ai/ui/icon-button"
 import { List, type ListRef } from "@opencode-ai/ui/list"
 import { ProviderIcon } from "@opencode-ai/ui/provider-icon"
 import { Spinner } from "@opencode-ai/ui/spinner"
+import { Tag } from "@opencode-ai/ui/tag"
 import { TextField } from "@opencode-ai/ui/text-field"
 import { showToast } from "@/utils/toast"
-import { type Accessor, createEffect, createMemo, createResource, Match, onCleanup, onMount, Switch } from "solid-js"
+import {
+  type Accessor,
+  type Component,
+  createEffect,
+  createMemo,
+  createResource,
+  Match,
+  onCleanup,
+  onMount,
+  Show,
+  Switch,
+} from "solid-js"
 import { createStore, produce } from "solid-js/store"
 import { Link } from "@/components/link"
 import { useServerSDK } from "@/context/server-sdk"
 import { useServerSync } from "@/context/server-sync"
 import { useLanguage } from "@/context/language"
-import { useProviders } from "@/hooks/use-providers"
+import { popularProviders, useProviders } from "@/hooks/use-providers"
+import { CustomProviderForm } from "./dialog-custom-provider"
 
-export function DialogConnectProvider(props: { provider: string; directory?: Accessor<string | undefined> }) {
+const CUSTOM_ID = "_custom"
+
+export function useProviderConnectController(options: { onBack?: () => void } = {}) {
+  const [store, setStore] = createStore({ selected: undefined as string | undefined })
+  const reset = () => setStore("selected", undefined)
+
+  return {
+    selected: () => store.selected,
+    select: (provider?: string) => setStore("selected", provider),
+    back: options.onBack ?? reset,
+  }
+}
+
+export const DialogConnectProvider: Component<{
+  directory?: Accessor<string | undefined>
+  controller?: ReturnType<typeof useProviderConnectController>
+}> = (props) => {
+  const fallback = useProviderConnectController()
+  const controller = props.controller ?? fallback
+  const language = useLanguage()
+  const reset = controller.back
+  const back = { current: reset }
+  const select = (provider?: string) => {
+    back.current = reset
+    controller.select(provider)
+  }
+
+  return (
+    <Dialog
+      class="h-full"
+      transition
+      title={
+        <Show when={controller.selected()} fallback={language.t("command.provider.connect")}>
+          <IconButton
+            tabIndex={-1}
+            icon="arrow-left"
+            variant="ghost"
+            onClick={() => back.current()}
+            aria-label={language.t("common.goBack")}
+          />
+        </Show>
+      }
+    >
+      <Switch>
+        <Match when={controller.selected() === CUSTOM_ID}>
+          <CustomProviderForm />
+        </Match>
+        <Match when={controller.selected() && controller.selected() !== CUSTOM_ID ? controller.selected() : undefined}>
+          {(provider) => (
+            <ProviderConnection
+              provider={provider()}
+              directory={props.directory}
+              onBack={reset}
+              setBack={(handler) => (back.current = handler)}
+            />
+          )}
+        </Match>
+        <Match when={true}>
+          <ProviderPicker directory={props.directory} onSelect={select} />
+        </Match>
+      </Switch>
+    </Dialog>
+  )
+}
+
+function ProviderPicker(props: { directory?: Accessor<string | undefined>; onSelect: (provider: string) => void }) {
+  const providers = useProviders(props.directory)
+  const language = useLanguage()
+  const popularGroup = () => language.t("dialog.provider.group.popular")
+  const otherGroup = () => language.t("dialog.provider.group.other")
+  const customLabel = () => language.t("settings.providers.tag.custom")
+  const note = (id: string) => {
+    if (id === "anthropic") return language.t("dialog.provider.anthropic.note")
+    if (id === "openai") return language.t("dialog.provider.openai.note")
+    if (id.startsWith("github-copilot")) return language.t("dialog.provider.copilot.note")
+    if (id === "opencode-go") return language.t("dialog.provider.opencodeGo.tagline")
+    return undefined
+  }
+
+  return (
+    <List
+      class="px-3"
+      search={{ placeholder: language.t("dialog.provider.search.placeholder"), autofocus: true }}
+      emptyMessage={language.t("dialog.provider.empty")}
+      activeIcon="plus-small"
+      key={(x) => x?.id}
+      items={() => {
+        language.locale()
+        return [{ id: CUSTOM_ID, name: customLabel() }, ...providers.all().values()]
+      }}
+      filterKeys={["id", "name"]}
+      groupBy={(x) => (popularProviders.includes(x.id) ? popularGroup() : otherGroup())}
+      sortBy={(a, b) => {
+        if (a.id === CUSTOM_ID) return -1
+        if (b.id === CUSTOM_ID) return 1
+        if (popularProviders.includes(a.id) && popularProviders.includes(b.id))
+          return popularProviders.indexOf(a.id) - popularProviders.indexOf(b.id)
+        return a.name.localeCompare(b.name)
+      }}
+      sortGroupsBy={(a, b) => {
+        const popular = popularGroup()
+        if (a.category === popular && b.category !== popular) return -1
+        if (b.category === popular && a.category !== popular) return 1
+        return 0
+      }}
+      onSelect={(x) => {
+        if (!x) return
+        props.onSelect(x.id)
+      }}
+    >
+      {(i) => (
+        <div class="px-1.25 w-full flex items-center gap-x-3">
+          <ProviderIcon data-slot="list-item-extra-icon" id={i.id} />
+          <span>{i.name}</span>
+          <Show when={i.id === "opencode"}>
+            <div class="text-14-regular text-text-weak">{language.t("dialog.provider.opencode.tagline")}</div>
+          </Show>
+          <Show when={i.id === CUSTOM_ID}>
+            <Tag>{language.t("settings.providers.tag.custom")}</Tag>
+          </Show>
+          <Show when={i.id === "opencode"}>
+            <Tag>{language.t("dialog.provider.tag.recommended")}</Tag>
+          </Show>
+          <Show when={note(i.id)}>{(value) => <div class="text-14-regular text-text-weak">{value()}</div>}</Show>
+          <Show when={i.id === "opencode-go"}>
+            <Tag>{language.t("dialog.provider.tag.recommended")}</Tag>
+          </Show>
+        </div>
+      )}
+    </List>
+  )
+}
+
+function ProviderConnection(props: {
+  provider: string
+  directory?: Accessor<string | undefined>
+  onBack: () => void
+  setBack: (handler: () => void) => void
+}) {
   const dialog = useDialog()
   const serverSync = useServerSync()
   const serverSDK = useServerSDK()
   const language = useLanguage()
   const providers = useProviders(props.directory)
 
-  const all = () => {
-    void import("./dialog-select-provider").then((x) => {
-      dialog.show(() => <x.DialogSelectProvider directory={props.directory} />)
-    })
-  }
-
   const alive = { value: true }
   const timer = { current: undefined as ReturnType<typeof setTimeout> | undefined }
 
@@ -364,21 +509,15 @@ export function DialogConnectProvider(props: { provider: string; directory?: Acc
   }
 
   function goBack() {
-    if (methods().length === 1) {
-      all()
-      return
-    }
-    if (store.authorization) {
+    if (methods().length > 1 && store.methodIndex !== undefined) {
       dispatch({ type: "method.reset" })
       return
     }
-    if (store.methodIndex !== undefined) {
-      dispatch({ type: "method.reset" })
-      return
-    }
-    all()
+    props.onBack()
   }
 
+  props.setBack(goBack)
+
   function MethodSelection() {
     return (
       <>
@@ -599,79 +738,67 @@ export function DialogConnectProvider(props: { provider: string; directory?: Acc
   }
 
   return (
-    <Dialog
-      title={
-        <IconButton
-          tabIndex={-1}
-          icon="arrow-left"
-          variant="ghost"
-          onClick={goBack}
-          aria-label={language.t("common.goBack")}
-        />
-      }
-    >
-      <div class="flex flex-col gap-6 px-2.5 pb-3">
-        <div class="px-2.5 flex gap-4 items-center">
-          <ProviderIcon id={props.provider} class="size-5 shrink-0 icon-strong-base" />
-          <div class="text-16-medium text-text-strong">
-            <Switch>
-              <Match when={props.provider === "anthropic" && method()?.label?.toLowerCase().includes("max")}>
-                {language.t("provider.connect.title.anthropicProMax")}
-              </Match>
-              <Match when={true}>{language.t("provider.connect.title", { provider: provider().name })}</Match>
-            </Switch>
-          </div>
-        </div>
-        <div class="px-2.5 pb-10 flex flex-col gap-6">
-          <div onKeyDown={handleKey} tabIndex={0} autofocus={store.methodIndex === undefined ? true : undefined}>
-            <Switch>
-              <Match when={loading()}>
-                <div class="text-14-regular text-text-base">
-                  <div class="flex items-center gap-x-2">
-                    <Spinner />
-                    <span>{language.t("provider.connect.status.inProgress")}</span>
-                  </div>
-                </div>
-              </Match>
-              <Match when={store.methodIndex === undefined}>
-                <MethodSelection />
-              </Match>
-              <Match when={store.state === "pending"}>
-                <div class="text-14-regular text-text-base">
-                  <div class="flex items-center gap-x-2">
-                    <Spinner />
-                    <span>{language.t("provider.connect.status.inProgress")}</span>
-                  </div>
-                </div>
-              </Match>
-              <Match when={store.state === "prompt"}>
-                <AuthPromptsView />
-              </Match>
-              <Match when={store.state === "error"}>
-                <div class="text-14-regular text-text-base">
-                  <div class="flex items-center gap-x-2">
-                    <Icon name="circle-ban-sign" class="text-icon-critical-base" />
-                    <span>{language.t("provider.connect.status.failed", { error: store.error ?? "" })}</span>
-                  </div>
-                </div>
-              </Match>
-              <Match when={method()?.type === "api"}>
-                <ApiAuthView />
-              </Match>
-              <Match when={method()?.type === "oauth"}>
-                <Switch>
-                  <Match when={store.authorization?.method === "code"}>
-                    <OAuthCodeView />
-                  </Match>
-                  <Match when={store.authorization?.method === "auto"}>
-                    <OAuthAutoView />
-                  </Match>
-                </Switch>
-              </Match>
-            </Switch>
-          </div>
+    <div class="flex flex-col gap-6 px-2.5 pb-3">
+      <div class="px-2.5 flex gap-4 items-center">
+        <ProviderIcon id={props.provider} class="size-5 shrink-0 icon-strong-base" />
+        <div class="text-16-medium text-text-strong">
+          <Switch>
+            <Match when={props.provider === "anthropic" && method()?.label?.toLowerCase().includes("max")}>
+              {language.t("provider.connect.title.anthropicProMax")}
+            </Match>
+            <Match when={true}>{language.t("provider.connect.title", { provider: provider().name })}</Match>
+          </Switch>
         </div>
       </div>
-    </Dialog>
+      <div class="px-2.5 pb-10 flex flex-col gap-6">
+        <div onKeyDown={handleKey} tabIndex={0} autofocus={store.methodIndex === undefined ? true : undefined}>
+          <Switch>
+            <Match when={loading()}>
+              <div class="text-14-regular text-text-base">
+                <div class="flex items-center gap-x-2">
+                  <Spinner />
+                  <span>{language.t("provider.connect.status.inProgress")}</span>
+                </div>
+              </div>
+            </Match>
+            <Match when={store.methodIndex === undefined}>
+              <MethodSelection />
+            </Match>
+            <Match when={store.state === "pending"}>
+              <div class="text-14-regular text-text-base">
+                <div class="flex items-center gap-x-2">
+                  <Spinner />
+                  <span>{language.t("provider.connect.status.inProgress")}</span>
+                </div>
+              </div>
+            </Match>
+            <Match when={store.state === "prompt"}>
+              <AuthPromptsView />
+            </Match>
+            <Match when={store.state === "error"}>
+              <div class="text-14-regular text-text-base">
+                <div class="flex items-center gap-x-2">
+                  <Icon name="circle-ban-sign" class="text-icon-critical-base" />
+                  <span>{language.t("provider.connect.status.failed", { error: store.error ?? "" })}</span>
+                </div>
+              </div>
+            </Match>
+            <Match when={method()?.type === "api"}>
+              <ApiAuthView />
+            </Match>
+            <Match when={method()?.type === "oauth"}>
+              <Switch>
+                <Match when={store.authorization?.method === "code"}>
+                  <OAuthCodeView />
+                </Match>
+                <Match when={store.authorization?.method === "auto"}>
+                  <OAuthAutoView />
+                </Match>
+              </Switch>
+            </Match>
+          </Switch>
+        </div>
+      </div>
+    </div>
   )
 }

packages/app/src/components/dialog-custom-provider.tsx

@@ -6,21 +6,41 @@ import { ProviderIcon } from "@opencode-ai/ui/provider-icon"
 import { useMutation } from "@tanstack/solid-query"
 import { TextField } from "@opencode-ai/ui/text-field"
 import { showToast } from "@/utils/toast"
-import { type Accessor, batch, For } from "solid-js"
+import { batch, For } from "solid-js"
 import { createStore, produce } from "solid-js/store"
 import { Link } from "@/components/link"
 import { useServerSDK } from "@/context/server-sdk"
 import { useServerSync } from "@/context/server-sync"
 import { useLanguage } from "@/context/language"
 import { type FormState, headerRow, modelRow, validateCustomProvider } from "./dialog-custom-provider-form"
-import { DialogSelectProvider } from "./dialog-select-provider"
 
 type Props = {
-  back?: "providers" | "close"
-  directory?: Accessor<string | undefined>
+  onBack: () => void
 }
 
 export function DialogCustomProvider(props: Props) {
+  const language = useLanguage()
+
+  return (
+    <Dialog
+      class="h-full"
+      title={
+        <IconButton
+          tabIndex={-1}
+          icon="arrow-left"
+          variant="ghost"
+          onClick={props.onBack}
+          aria-label={language.t("common.goBack")}
+        />
+      }
+      transition
+    >
+      <CustomProviderForm />
+    </Dialog>
+  )
+}
+
+export function CustomProviderForm() {
   const dialog = useDialog()
   const serverSync = useServerSync()
   const serverSDK = useServerSDK()
@@ -36,14 +56,6 @@ export function DialogCustomProvider(props: Props) {
     err: {},
   })
 
-  const goBack = () => {
-    if (props.back === "close") {
-      dialog.close()
-      return
-    }
-    dialog.show(() => <DialogSelectProvider directory={props.directory} />)
-  }
-
   const addModel = () => {
     setForm(
       "models",
@@ -163,168 +175,155 @@ export function DialogCustomProvider(props: Props) {
   }
 
   return (
-    <Dialog
-      title={
-        <IconButton
-          tabIndex={-1}
-          icon="arrow-left"
-          variant="ghost"
-          onClick={goBack}
-          aria-label={language.t("common.goBack")}
-        />
-      }
-      transition
-    >
-      <div class="flex flex-col gap-6 px-2.5 pb-3 overflow-y-auto max-h-[60vh]">
-        <div class="px-2.5 flex gap-4 items-center">
-          <ProviderIcon id="synthetic" class="size-5 shrink-0 icon-strong-base" />
-          <div class="text-16-medium text-text-strong">{language.t("provider.custom.title")}</div>
+    <div class="flex flex-col gap-6 px-2.5 pb-3 overflow-y-auto max-h-[60vh]">
+      <div class="px-2.5 flex gap-4 items-center">
+        <ProviderIcon id="synthetic" class="size-5 shrink-0 icon-strong-base" />
+        <div class="text-16-medium text-text-strong">{language.t("provider.custom.title")}</div>
+      </div>
+
+      <form onSubmit={save} class="px-2.5 pb-6 flex flex-col gap-6">
+        <p class="text-14-regular text-text-base">
+          {language.t("provider.custom.description.prefix")}
+          <Link href="https://opencode.ai/docs/providers/#custom-provider" tabIndex={-1}>
+            {language.t("provider.custom.description.link")}
+          </Link>
+          {language.t("provider.custom.description.suffix")}
+        </p>
+
+        <div class="flex flex-col gap-4">
+          <TextField
+            autofocus
+            label={language.t("provider.custom.field.providerID.label")}
+            placeholder={language.t("provider.custom.field.providerID.placeholder")}
+            description={language.t("provider.custom.field.providerID.description")}
+            value={form.providerID}
+            onChange={(v) => setField("providerID", v)}
+            validationState={form.err.providerID ? "invalid" : undefined}
+            error={form.err.providerID}
+          />
+          <TextField
+            label={language.t("provider.custom.field.name.label")}
+            placeholder={language.t("provider.custom.field.name.placeholder")}
+            value={form.name}
+            onChange={(v) => setField("name", v)}
+            validationState={form.err.name ? "invalid" : undefined}
+            error={form.err.name}
+          />
+          <TextField
+            label={language.t("provider.custom.field.baseURL.label")}
+            placeholder={language.t("provider.custom.field.baseURL.placeholder")}
+            value={form.baseURL}
+            onChange={(v) => setField("baseURL", v)}
+            validationState={form.err.baseURL ? "invalid" : undefined}
+            error={form.err.baseURL}
+          />
+          <TextField
+            label={language.t("provider.custom.field.apiKey.label")}
+            placeholder={language.t("provider.custom.field.apiKey.placeholder")}
+            description={language.t("provider.custom.field.apiKey.description")}
+            value={form.apiKey}
+            onChange={(v) => setField("apiKey", v)}
+          />
         </div>
 
-        <form onSubmit={save} class="px-2.5 pb-6 flex flex-col gap-6">
-          <p class="text-14-regular text-text-base">
-            {language.t("provider.custom.description.prefix")}
-            <Link href="https://opencode.ai/docs/providers/#custom-provider" tabIndex={-1}>
-              {language.t("provider.custom.description.link")}
-            </Link>
-            {language.t("provider.custom.description.suffix")}
-          </p>
-
-          <div class="flex flex-col gap-4">
-            <TextField
-              autofocus
-              label={language.t("provider.custom.field.providerID.label")}
-              placeholder={language.t("provider.custom.field.providerID.placeholder")}
-              description={language.t("provider.custom.field.providerID.description")}
-              value={form.providerID}
-              onChange={(v) => setField("providerID", v)}
-              validationState={form.err.providerID ? "invalid" : undefined}
-              error={form.err.providerID}
-            />
-            <TextField
-              label={language.t("provider.custom.field.name.label")}
-              placeholder={language.t("provider.custom.field.name.placeholder")}
-              value={form.name}
-              onChange={(v) => setField("name", v)}
-              validationState={form.err.name ? "invalid" : undefined}
-              error={form.err.name}
-            />
-            <TextField
-              label={language.t("provider.custom.field.baseURL.label")}
-              placeholder={language.t("provider.custom.field.baseURL.placeholder")}
-              value={form.baseURL}
-              onChange={(v) => setField("baseURL", v)}
-              validationState={form.err.baseURL ? "invalid" : undefined}
-              error={form.err.baseURL}
-            />
-            <TextField
-              label={language.t("provider.custom.field.apiKey.label")}
-              placeholder={language.t("provider.custom.field.apiKey.placeholder")}
-              description={language.t("provider.custom.field.apiKey.description")}
-              value={form.apiKey}
-              onChange={(v) => setField("apiKey", v)}
-            />
-          </div>
-
-          <div class="flex flex-col gap-3">
-            <label class="text-12-medium text-text-weak">{language.t("provider.custom.models.label")}</label>
-            <For each={form.models}>
-              {(m, i) => (
-                <div class="flex gap-2 items-start" data-row={m.row}>
-                  <div class="flex-1">
-                    <TextField
-                      label={language.t("provider.custom.models.id.label")}
-                      hideLabel
-                      placeholder={language.t("provider.custom.models.id.placeholder")}
-                      value={m.id}
-                      onChange={(v) => setModel(i(), "id", v)}
-                      validationState={m.err.id ? "invalid" : undefined}
-                      error={m.err.id}
-                    />
-                  </div>
-                  <div class="flex-1">
-                    <TextField
-                      label={language.t("provider.custom.models.name.label")}
-                      hideLabel
-                      placeholder={language.t("provider.custom.models.name.placeholder")}
-                      value={m.name}
-                      onChange={(v) => setModel(i(), "name", v)}
-                      validationState={m.err.name ? "invalid" : undefined}
-                      error={m.err.name}
-                    />
-                  </div>
-                  <IconButton
-                    type="button"
-                    icon="trash"
-                    variant="ghost"
-                    class="mt-1.5"
-                    onClick={() => removeModel(i())}
-                    disabled={form.models.length <= 1}
-                    aria-label={language.t("provider.custom.models.remove")}
+        <div class="flex flex-col gap-3">
+          <label class="text-12-medium text-text-weak">{language.t("provider.custom.models.label")}</label>
+          <For each={form.models}>
+            {(m, i) => (
+              <div class="flex gap-2 items-start" data-row={m.row}>
+                <div class="flex-1">
+                  <TextField
+                    label={language.t("provider.custom.models.id.label")}
+                    hideLabel
+                    placeholder={language.t("provider.custom.models.id.placeholder")}
+                    value={m.id}
+                    onChange={(v) => setModel(i(), "id", v)}
+                    validationState={m.err.id ? "invalid" : undefined}
+                    error={m.err.id}
                   />
                 </div>
-              )}
-            </For>
-            <Button type="button" size="small" variant="ghost" icon="plus-small" onClick={addModel} class="self-start">
-              {language.t("provider.custom.models.add")}
-            </Button>
-          </div>
-
-          <div class="flex flex-col gap-3">
-            <label class="text-12-medium text-text-weak">{language.t("provider.custom.headers.label")}</label>
-            <For each={form.headers}>
-              {(h, i) => (
-                <div class="flex gap-2 items-start" data-row={h.row}>
-                  <div class="flex-1">
-                    <TextField
-                      label={language.t("provider.custom.headers.key.label")}
-                      hideLabel
-                      placeholder={language.t("provider.custom.headers.key.placeholder")}
-                      value={h.key}
-                      onChange={(v) => setHeader(i(), "key", v)}
-                      validationState={h.err.key ? "invalid" : undefined}
-                      error={h.err.key}
-                    />
-                  </div>
-                  <div class="flex-1">
-                    <TextField
-                      label={language.t("provider.custom.headers.value.label")}
-                      hideLabel
-                      placeholder={language.t("provider.custom.headers.value.placeholder")}
-                      value={h.value}
-                      onChange={(v) => setHeader(i(), "value", v)}
-                      validationState={h.err.value ? "invalid" : undefined}
-                      error={h.err.value}
-                    />
-                  </div>
-                  <IconButton
-                    type="button"
-                    icon="trash"
-                    variant="ghost"
-                    class="mt-1.5"
-                    onClick={() => removeHeader(i())}
-                    disabled={form.headers.length <= 1}
-                    aria-label={language.t("provider.custom.headers.remove")}
+                <div class="flex-1">
+                  <TextField
+                    label={language.t("provider.custom.models.name.label")}
+                    hideLabel
+                    placeholder={language.t("provider.custom.models.name.placeholder")}
+                    value={m.name}
+                    onChange={(v) => setModel(i(), "name", v)}
+                    validationState={m.err.name ? "invalid" : undefined}
+                    error={m.err.name}
                   />
                 </div>
-              )}
-            </For>
-            <Button type="button" size="small" variant="ghost" icon="plus-small" onClick={addHeader} class="self-start">
-              {language.t("provider.custom.headers.add")}
-            </Button>
-          </div>
-
-          <Button
-            class="w-auto self-start"
-            type="submit"
-            size="large"
-            variant="primary"
-            disabled={saveMutation.isPending}
-          >
-            {saveMutation.isPending ? language.t("common.saving") : language.t("common.submit")}
+                <IconButton
+                  type="button"
+                  icon="trash"
+                  variant="ghost"
+                  class="mt-1.5"
+                  onClick={() => removeModel(i())}
+                  disabled={form.models.length <= 1}
+                  aria-label={language.t("provider.custom.models.remove")}
+                />
+              </div>
+            )}
+          </For>
+          <Button type="button" size="small" variant="ghost" icon="plus-small" onClick={addModel} class="self-start">
+            {language.t("provider.custom.models.add")}
           </Button>
-        </form>
-      </div>
-    </Dialog>
+        </div>
+
+        <div class="flex flex-col gap-3">
+          <label class="text-12-medium text-text-weak">{language.t("provider.custom.headers.label")}</label>
+          <For each={form.headers}>
+            {(h, i) => (
+              <div class="flex gap-2 items-start" data-row={h.row}>
+                <div class="flex-1">
+                  <TextField
+                    label={language.t("provider.custom.headers.key.label")}
+                    hideLabel
+                    placeholder={language.t("provider.custom.headers.key.placeholder")}
+                    value={h.key}
+                    onChange={(v) => setHeader(i(), "key", v)}
+                    validationState={h.err.key ? "invalid" : undefined}
+                    error={h.err.key}
+                  />
+                </div>
+                <div class="flex-1">
+                  <TextField
+                    label={language.t("provider.custom.headers.value.label")}
+                    hideLabel
+                    placeholder={language.t("provider.custom.headers.value.placeholder")}
+                    value={h.value}
+                    onChange={(v) => setHeader(i(), "value", v)}
+                    validationState={h.err.value ? "invalid" : undefined}
+                    error={h.err.value}
+                  />
+                </div>
+                <IconButton
+                  type="button"
+                  icon="trash"
+                  variant="ghost"
+                  class="mt-1.5"
+                  onClick={() => removeHeader(i())}
+                  disabled={form.headers.length <= 1}
+                  aria-label={language.t("provider.custom.headers.remove")}
+                />
+              </div>
+            )}
+          </For>
+          <Button type="button" size="small" variant="ghost" icon="plus-small" onClick={addHeader} class="self-start">
+            {language.t("provider.custom.headers.add")}
+          </Button>
+        </div>
+
+        <Button
+          class="w-auto self-start"
+          type="submit"
+          size="large"
+          variant="primary"
+          disabled={saveMutation.isPending}
+        >
+          {saveMutation.isPending ? language.t("common.saving") : language.t("common.submit")}
+        </Button>
+      </form>
+    </div>
   )
 }

packages/app/src/components/dialog-manage-models.tsx

@@ -3,13 +3,26 @@ import { List } from "@opencode-ai/ui/list"
 import { Switch } from "@opencode-ai/ui/switch"
 import { Tooltip } from "@opencode-ai/ui/tooltip"
 import { Button } from "@opencode-ai/ui/button"
-import type { Component } from "solid-js"
+import { ButtonV2 } from "@opencode-ai/ui/v2/button-v2"
+import { Dialog as DialogV2, DialogBody, DialogHeader, DialogTitleGroup } from "@opencode-ai/ui/v2/dialog-v2"
+import { Icon as IconV2 } from "@opencode-ai/ui/v2/icon"
+import { IconButtonV2 } from "@opencode-ai/ui/v2/icon-button-v2"
+import { TextInputV2 } from "@opencode-ai/ui/v2/text-input-v2"
+import { Switch as SwitchV2 } from "@opencode-ai/ui/v2/switch-v2"
+import { ProviderIcon } from "@opencode-ai/ui/provider-icon"
+import { useFilteredList } from "@opencode-ai/ui/hooks"
+import { For, Show, type Component } from "solid-js"
 import { useLocal } from "@/context/local"
 import { popularProviders } from "@/hooks/use-providers"
 import { useLanguage } from "@/context/language"
 import { useDialog } from "@opencode-ai/ui/context/dialog"
-import { DialogSelectProvider } from "./dialog-select-provider"
+import { DialogConnectProvider } from "./dialog-connect-provider"
 import { decode64 } from "@/utils/base64"
+import { SettingsListV2 } from "./settings-v2/parts/list"
+import { SettingsRowV2 } from "./settings-v2/parts/row"
+import "./settings-v2/settings-v2.css"
+
+type ModelItem = ReturnType<ReturnType<typeof useLocal>["model"]["list"]>[number]
 
 export const DialogManageModels: Component = () => {
   const local = useLocal()
@@ -18,7 +31,7 @@ export const DialogManageModels: Component = () => {
   const directory = () => decode64(local.slug())
 
   const handleConnectProvider = () => {
-    dialog.show(() => <DialogSelectProvider directory={directory} />)
+    void dialog.show(() => <DialogConnectProvider directory={directory} />)
   }
   const providerRank = (id: string) => popularProviders.indexOf(id)
   const providerList = (providerID: string) => local.model.list().filter((x) => x.provider.id === providerID)
@@ -102,3 +115,151 @@ export const DialogManageModels: Component = () => {
     </Dialog>
   )
 }
+
+export const DialogManageModelsV2: Component = () => {
+  const local = useLocal()
+  const language = useLanguage()
+  const dialog = useDialog()
+  const directory = () => decode64(local.slug())
+
+  const handleConnectProvider = () => {
+    void dialog.show(() => <DialogConnectProvider directory={directory} />)
+  }
+  const providerList = (providerID: string) => local.model.list().filter((x) => x.provider.id === providerID)
+  const providerVisible = (providerID: string) =>
+    providerList(providerID).every((x) => local.model.visible({ modelID: x.id, providerID: x.provider.id }))
+  const setProviderVisibility = (providerID: string, checked: boolean) => {
+    providerList(providerID).forEach((x) => {
+      local.model.setVisibility({ modelID: x.id, providerID: x.provider.id }, checked)
+    })
+  }
+  const setModelVisibility = (item: ModelItem, checked: boolean) => {
+    local.model.setVisibility({ modelID: item.id, providerID: item.provider.id }, checked)
+  }
+  const list = useFilteredList<ModelItem>({
+    items: () => local.model.list(),
+    key: (x) => `${x.provider.id}:${x.id}`,
+    filterKeys: ["provider.name", "name", "id"],
+    sortBy: (a, b) => a.name.localeCompare(b.name),
+    groupBy: (x) => x.provider.id,
+    sortGroupsBy: (a, b) => {
+      const aRank = popularProviders.indexOf(a.category)
+      const bRank = popularProviders.indexOf(b.category)
+      const aPopular = aRank >= 0
+      const bPopular = bRank >= 0
+      if (aPopular && !bPopular) return -1
+      if (!aPopular && bPopular) return 1
+      return aRank - bRank
+    },
+  })
+
+  return (
+    <DialogV2 size="large" variant="settings" class="settings-v2-manage-models-dialog">
+      <DialogHeader hideClose={true} closeLabel={language.t("common.close")}>
+        <DialogTitleGroup
+          title={language.t("dialog.model.manage")}
+          description={language.t("dialog.model.manage.description")}
+        />
+        <ButtonV2 variant="neutral" icon="plus" onClick={handleConnectProvider}>
+          {language.t("command.provider.connect")}
+        </ButtonV2>
+      </DialogHeader>
+      <DialogBody class="flex min-h-0 flex-1 flex-col">
+        <div class="px-4 pt-px pb-3">
+          <div class="relative">
+            <TextInputV2
+              type="search"
+              appearance="base"
+              class="!w-full self-stretch"
+              value={list.filter()}
+              onInput={(event) => list.onInput(event.currentTarget.value)}
+              placeholder={language.t("dialog.model.search.placeholder")}
+              spellcheck={false}
+              autocorrect="off"
+              autocomplete="off"
+              autocapitalize="off"
+              autofocus
+              aria-label={language.t("dialog.model.search.placeholder")}
+            />
+            <Show when={list.filter()}>
+              <IconButtonV2
+                type="button"
+                variant="ghost-muted"
+                size="small"
+                class="settings-v2-tab-search-clear"
+                icon={<IconV2 name="close" size="large" class="text-v2-icon-icon-muted" />}
+                onClick={() => list.clear()}
+                aria-label={language.t("common.clear")}
+              />
+            </Show>
+          </div>
+        </div>
+        <div data-slot="manage-models-scroll" class="relative min-h-0 flex-1">
+          <div class="settings-v2-panel settings-v2-models h-full px-4 pt-4 pb-4">
+            <Show
+              when={!list.grouped.loading}
+              fallback={
+                <div class="settings-v2-models-status">
+                  {language.t("common.loading")}
+                  {language.t("common.loading.ellipsis")}
+                </div>
+              }
+            >
+              <Show
+                when={list.flat().length > 0}
+                fallback={
+                  <div class="settings-v2-models-status">
+                    <span>{language.t("dialog.model.empty")}</span>
+                    <Show when={list.filter()}>
+                      <span class="settings-v2-models-status-filter">&quot;{list.filter()}&quot;</span>
+                    </Show>
+                  </div>
+                }
+              >
+                <For each={list.grouped.latest}>
+                  {(group) => (
+                    <div class="settings-v2-section" data-component="settings-models-provider">
+                      <div class="settings-v2-models-group-header justify-between">
+                        <div class="flex min-w-0 items-center gap-2">
+                          <ProviderIcon id={group.category} width={16} height={16} class="ml-4 shrink-0" />
+                          <h3 class="settings-v2-section-title">{group.items[0].provider.name}</h3>
+                        </div>
+                        <div>
+                          <SwitchV2
+                            class="mr-6"
+                            checked={providerVisible(group.category)}
+                            onChange={(checked) => setProviderVisibility(group.category, checked)}
+                            hideLabel
+                          >
+                            {group.items[0].provider.name}
+                          </SwitchV2>
+                        </div>
+                      </div>
+                      <SettingsListV2>
+                        <For each={group.items}>
+                          {(item) => (
+                            <SettingsRowV2 title={item.name} description="">
+                              <div>
+                                <SwitchV2
+                                  checked={local.model.visible({ modelID: item.id, providerID: item.provider.id })}
+                                  onChange={(checked) => setModelVisibility(item, checked)}
+                                  hideLabel
+                                >
+                                  {item.name}
+                                </SwitchV2>
+                              </div>
+                            </SettingsRowV2>
+                          )}
+                        </For>
+                      </SettingsListV2>
+                    </div>
+                  )}
+                </For>
+              </Show>
+            </Show>
+          </div>
+        </div>
+      </DialogBody>
+    </DialogV2>
+  )
+}

packages/app/src/components/dialog-select-file.tsx

@@ -1,329 +1,84 @@
-import { useDialog } from "@opencode-ai/ui/context/dialog"
 import { Dialog } from "@opencode-ai/ui/dialog"
 import { FileIcon } from "@opencode-ai/ui/file-icon"
 import { Icon } from "@opencode-ai/ui/icon"
 import { Keybind } from "@opencode-ai/ui/keybind"
 import { List } from "@opencode-ai/ui/list"
-import { base64Encode } from "@opencode-ai/core/util/encode"
 import { getDirectory, getFilename } from "@opencode-ai/core/util/path"
-import { useNavigate } from "@solidjs/router"
-import { createMemo, createSignal, lazy, Match, onCleanup, Show, Switch } from "solid-js"
-import { formatKeybind, useCommand, type CommandOption } from "@/context/command"
-import { useServerSDK, type ServerSDK } from "@/context/server-sdk"
-import { useServerSync } from "@/context/server-sync"
-import { useLayout } from "@/context/layout"
-import { useFile } from "@/context/file"
+import { createMemo, createSignal, lazy, Match, Show, Switch } from "solid-js"
+import { formatKeybind } from "@/context/command"
+import { useServerSDK } from "@/context/server-sdk"
 import { useLanguage } from "@/context/language"
 import { usePlatform } from "@/context/platform"
 import { useSettings } from "@/context/settings"
 import { useSessionLayout } from "@/pages/session/session-layout"
-import { createSessionTabs } from "@/pages/session/helpers"
 import { decode64 } from "@/utils/base64"
 import { getRelativeTime } from "@/utils/time"
+import {
+  createCommandPaletteFileEntry,
+  createCommandPaletteFileOpener,
+  createCommandPaletteModel,
+  uniqueCommandPaletteEntries,
+  type CommandPaletteEntry,
+} from "./command-palette"
 
 const DialogSelectFileV2 = lazy(() =>
   import("./dialog-select-directory-v2").then((module) => ({ default: module.DialogSelectDirectoryV2 })),
 )
-
-type EntryType = "command" | "file" | "session"
-
-type Entry = {
-  id: string
-  type: EntryType
-  title: string
-  description?: string
-  keybind?: string
-  category: string
-  option?: CommandOption
-  path?: string
-  directory?: string
-  sessionID?: string
-  archived?: number
-  updated?: number
-}
+const DialogCommandPaletteV2 = lazy(() =>
+  import("./dialog-command-palette-v2").then((module) => ({ default: module.DialogCommandPaletteV2 })),
+)
 
 type DialogSelectFileMode = "all" | "files"
 
-const ENTRY_LIMIT = 5
-const COMMON_COMMAND_IDS = [
-  "session.new",
-  "workspace.new",
-  "session.previous",
-  "session.next",
-  "terminal.toggle",
-  "review.toggle",
-] as const
-
-const uniqueEntries = (items: Entry[]) => {
-  const seen = new Set<string>()
-  const out: Entry[] = []
-  for (const item of items) {
-    if (seen.has(item.id)) continue
-    seen.add(item.id)
-    out.push(item)
-  }
-  return out
-}
-
-const createCommandEntry = (option: CommandOption, category: string): Entry => ({
-  id: "command:" + option.id,
-  type: "command",
-  title: option.title,
-  description: option.description,
-  keybind: option.keybind,
-  category,
-  option,
-})
-
-const createFileEntry = (path: string, category: string): Entry => ({
-  id: "file:" + path,
-  type: "file",
-  title: path,
-  category,
-  path,
-})
-
-const createSessionEntry = (
-  input: {
-    directory: string
-    id: string
-    title: string
-    description: string
-    archived?: number
-    updated?: number
-  },
-  category: string,
-): Entry => ({
-  id: `session:${input.directory}:${input.id}`,
-  type: "session",
-  title: input.title,
-  description: input.description,
-  category,
-  directory: input.directory,
-  sessionID: input.id,
-  archived: input.archived,
-  updated: input.updated,
-})
-
-function createCommandEntries(props: {
-  filesOnly: () => boolean
-  command: ReturnType<typeof useCommand>
-  language: ReturnType<typeof useLanguage>
-}) {
-  const allowed = createMemo(() => {
-    if (props.filesOnly()) return []
-    return props.command.options.filter(
-      (option) =>
-        !option.disabled && !option.hidden && !option.id.startsWith("suggested.") && option.id !== "file.open",
-    )
-  })
-
-  const list = createMemo(() => {
-    const category = props.language.t("palette.group.commands")
-    return allowed().map((option) => createCommandEntry(option, category))
-  })
-
-  const picks = createMemo(() => {
-    const all = allowed()
-    const order = new Map<string, number>(COMMON_COMMAND_IDS.map((id, index) => [id, index]))
-    const picked = all.filter((option) => order.has(option.id))
-    const base = picked.length ? picked : all.slice(0, ENTRY_LIMIT)
-    const sorted = picked.length ? [...base].sort((a, b) => (order.get(a.id) ?? 0) - (order.get(b.id) ?? 0)) : base
-    const category = props.language.t("palette.group.commands")
-    return sorted.map((option) => createCommandEntry(option, category))
-  })
-
-  return { allowed, list, picks }
-}
-
-function createFileEntries(props: {
-  file: ReturnType<typeof useFile>
-  tabs: () => ReturnType<ReturnType<typeof useLayout>["tabs"]>
-  language: ReturnType<typeof useLanguage>
-}) {
-  const tabState = createSessionTabs({
-    tabs: props.tabs,
-    pathFromTab: props.file.pathFromTab,
-    normalizeTab: (tab) => (tab.startsWith("file://") ? props.file.tab(tab) : tab),
-  })
-  const recent = createMemo(() => {
-    const all = tabState.openedTabs()
-    const active = tabState.activeFileTab()
-    const order = active ? [active, ...all.filter((item) => item !== active)] : all
-    const seen = new Set<string>()
-    const category = props.language.t("palette.group.files")
-    const items: Entry[] = []
-
-    for (const item of order) {
-      const path = props.file.pathFromTab(item)
-      if (!path) continue
-      if (seen.has(path)) continue
-      seen.add(path)
-      items.push(createFileEntry(path, category))
-    }
-
-    return items.slice(0, ENTRY_LIMIT)
-  })
-
-  const root = createMemo(() => {
-    const category = props.language.t("palette.group.files")
-    const nodes = props.file.tree.children("")
-    const paths = nodes
-      .filter((node) => node.type === "file")
-      .map((node) => node.path)
-      .sort((a, b) => a.localeCompare(b))
-    return paths.slice(0, ENTRY_LIMIT).map((path) => createFileEntry(path, category))
-  })
-
-  return { recent, root }
-}
-
-function createSessionEntries(props: {
-  workspaces: () => string[]
-  label: (directory: string) => string
-  serverSDK: ServerSDK
-  language: ReturnType<typeof useLanguage>
-}) {
-  const state: {
-    token: number
-    inflight: Promise<Entry[]> | undefined
-    cached: Entry[] | undefined
-  } = {
-    token: 0,
-    inflight: undefined,
-    cached: undefined,
-  }
-
-  const sessions = (text: string) => {
-    const query = text.trim()
-    if (!query) {
-      state.token += 1
-      state.inflight = undefined
-      state.cached = undefined
-      return [] as Entry[]
-    }
-
-    if (state.cached) return state.cached
-    if (state.inflight) return state.inflight
-
-    const current = state.token
-    const dirs = props.workspaces()
-    if (dirs.length === 0) return [] as Entry[]
-
-    state.inflight = Promise.all(
-      dirs.map((directory) => {
-        const description = props.label(directory)
-        return props.serverSDK.client.session
-          .list({ directory, roots: true })
-          .then((x) =>
-            (x.data ?? [])
-              .filter((s) => !!s?.id)
-              .map((s) => ({
-                id: s.id,
-                title: s.title ?? props.language.t("command.session.new"),
-                description,
-                directory,
-                archived: s.time?.archived,
-                updated: s.time?.updated,
-              })),
-          )
-          .catch(
-            () =>
-              [] as {
-                id: string
-                title: string
-                description: string
-                directory: string
-                archived?: number
-                updated?: number
-              }[],
-          )
-      }),
-    )
-      .then((results) => {
-        if (state.token !== current) return [] as Entry[]
-        const seen = new Set<string>()
-        const category = props.language.t("command.category.session")
-        const next = results
-          .flat()
-          .filter((item) => {
-            const key = `${item.directory}:${item.id}`
-            if (seen.has(key)) return false
-            seen.add(key)
-            return true
-          })
-          .map((item) => createSessionEntry(item, category))
-        state.cached = next
-        return next
-      })
-      .catch(() => [] as Entry[])
-      .finally(() => {
-        state.inflight = undefined
-      })
-
-    return state.inflight
-  }
-
-  return { sessions }
-}
-
 export function DialogSelectFile(props: { mode?: DialogSelectFileMode; onOpenFile?: (path: string) => void }) {
-  const command = useCommand()
-  const language = useLanguage()
   const platform = usePlatform()
   const settings = useSettings()
-  const layout = useLayout()
-  const file = useFile()
-  const dialog = useDialog()
-  const navigate = useNavigate()
-  const serverSDK = useServerSDK()
-  const serverSync = useServerSync()
-  const { params, tabs, view } = useSessionLayout()
   const filesOnly = () => props.mode === "files"
-  const state = { cleanup: undefined as (() => void) | void, committed: false }
-  const [grouped, setGrouped] = createSignal(false)
-  const commandEntries = createCommandEntries({ filesOnly, command, language })
-  const fileEntries = createFileEntries({ file, tabs, language })
 
-  const projectDirectory = createMemo(() => decode64(params.dir) ?? "")
-  const project = createMemo(() => {
-    const directory = projectDirectory()
-    if (!directory) return
-    return layout.projects.list().find((p) => p.worktree === directory || p.sandboxes?.includes(directory))
-  })
-  const workspaces = createMemo(() => {
-    const directory = projectDirectory()
-    const current = project()
-    if (!current) return directory ? [directory] : []
-
-    const dirs = [current.worktree, ...(current.sandboxes ?? [])]
-    if (directory && !dirs.includes(directory)) return [...dirs, directory]
-    return dirs
-  })
-  const homedir = createMemo(() => serverSync().data.path.home)
-  const label = (directory: string) => {
-    const current = project()
-    const kind =
-      current && directory === current.worktree
-        ? language.t("workspace.type.local")
-        : language.t("workspace.type.sandbox")
-    const [store] = serverSync().child(directory, { bootstrap: false })
-    const home = homedir()
-    const path = home ? directory.replace(home, "~") : directory
-    const name = store.vcs?.branch ?? getFilename(directory)
-    return `${kind} : ${name || path}`
+  if (!filesOnly() && settings.general.newLayoutDesigns()) {
+    return <DialogCommandPaletteV2 onOpenFile={props.onOpenFile} />
   }
 
-  const { sessions } = createSessionEntries({ workspaces, label, serverSDK: serverSDK(), language })
+  if (filesOnly() && platform.platform === "desktop" && settings.general.newLayoutDesigns()) {
+    return <DialogSelectFileDesktopV2 onOpenFile={props.onOpenFile} />
+  }
+
+  return <DialogSelectFileLegacy filesOnly={filesOnly} onOpenFile={props.onOpenFile} />
+}
+
+function DialogSelectFileDesktopV2(props: { onOpenFile?: (path: string) => void }) {
+  const language = useLanguage()
+  const serverSDK = useServerSDK()
+  const { params } = useSessionLayout()
+  const projectDirectory = createMemo(() => decode64(params.dir) ?? "")
+  const openFile = createCommandPaletteFileOpener(props.onOpenFile)
+
+  return (
+    <DialogSelectFileV2
+      server={serverSDK().server}
+      mode="file"
+      start={projectDirectory()}
+      title={language.t("session.header.searchFiles")}
+      onSelect={(result) => {
+        if (typeof result !== "string") return
+        openFile(result)
+      }}
+    />
+  )
+}
+
+function DialogSelectFileLegacy(props: { filesOnly: () => boolean; onOpenFile?: (path: string) => void }) {
+  const palette = createCommandPaletteModel(props)
+  const [grouped, setGrouped] = createSignal(false)
 
   const items = async (text: string) => {
     const query = text.trim()
     setGrouped(query.length > 0)
 
-    if (!query && filesOnly()) {
-      const loaded = file.tree.state("")?.loaded
-      const pending = loaded ? Promise.resolve() : file.tree.list("")
-      const next = uniqueEntries([...fileEntries.recent(), ...fileEntries.root()])
+    if (!query && props.filesOnly()) {
+      const loaded = palette.file.tree.state("")?.loaded
+      const pending = loaded ? Promise.resolve() : palette.file.tree.list("")
+      const next = uniqueCommandPaletteEntries([...palette.recentFileEntries(), ...palette.rootFileEntries()])
 
       if (loaded || next.length > 0) {
         void pending
@@ -331,79 +86,24 @@ export function DialogSelectFile(props: { mode?: DialogSelectFileMode; onOpenFil
       }
 
       await pending
-      return uniqueEntries([...fileEntries.recent(), ...fileEntries.root()])
+      return uniqueCommandPaletteEntries([...palette.recentFileEntries(), ...palette.rootFileEntries()])
     }
 
-    if (!query) return [...commandEntries.picks(), ...fileEntries.recent()]
+    if (!query) return [...palette.preferredCommandEntries(), ...palette.recentFileEntries()]
 
-    if (filesOnly()) {
-      const files = await file.searchFiles(query)
-      const category = language.t("palette.group.files")
-      return files.map((path) => createFileEntry(path, category))
+    if (props.filesOnly()) {
+      const files = await palette.file.searchFiles(query)
+      const category = palette.language.t("palette.group.files")
+      return files.map((path) => createCommandPaletteFileEntry(path, category))
     }
 
-    const [files, nextSessions] = await Promise.all([file.searchFiles(query), Promise.resolve(sessions(query))])
-    const category = language.t("palette.group.files")
-    const entries = files.map((path) => createFileEntry(path, category))
-    return [...commandEntries.list(), ...nextSessions, ...entries]
-  }
-
-  const handleMove = (item: Entry | undefined) => {
-    state.cleanup?.()
-    if (!item) return
-    if (item.type !== "command") return
-    state.cleanup = item.option?.onHighlight?.()
-  }
-
-  const open = (path: string) => {
-    const value = file.tab(path)
-    void tabs().open(value)
-    void file.load(path)
-    if (!view().reviewPanel.opened()) view().reviewPanel.open()
-    layout.fileTree.setTab("all")
-    props.onOpenFile?.(path)
-    tabs().setActive(value)
-  }
-
-  const handleSelect = (item: Entry | undefined) => {
-    if (!item) return
-    state.committed = true
-    state.cleanup = undefined
-    dialog.close()
-
-    if (item.type === "command") {
-      item.option?.onSelect?.("palette")
-      return
-    }
-
-    if (item.type === "session") {
-      if (!item.directory || !item.sessionID) return
-      navigate(`/${base64Encode(item.directory)}/session/${item.sessionID}`)
-      return
-    }
-
-    if (!item.path) return
-    open(item.path)
-  }
-
-  onCleanup(() => {
-    if (state.committed) return
-    state.cleanup?.()
-  })
-
-  if (filesOnly() && platform.platform === "desktop" && settings.general.newLayoutDesigns()) {
-    return (
-      <DialogSelectFileV2
-        server={serverSDK().server}
-        mode="file"
-        start={projectDirectory()}
-        title={language.t("session.header.searchFiles")}
-        onSelect={(result) => {
-          if (typeof result !== "string") return
-          open(result)
-        }}
-      />
-    )
+    const [files, nextSessions] = await Promise.all([
+      palette.file.searchFiles(query),
+      Promise.resolve(palette.sessions(query)),
+    ])
+    const category = palette.language.t("palette.group.files")
+    const entries = files.map((path) => createCommandPaletteFileEntry(path, category))
+    return [...palette.commandEntries(), ...nextSessions, ...entries]
   }
 
   return (
@@ -411,21 +111,21 @@ export function DialogSelectFile(props: { mode?: DialogSelectFileMode; onOpenFil
       <List
         class="px-3"
         search={{
-          placeholder: filesOnly()
-            ? language.t("session.header.searchFiles")
-            : language.t("palette.search.placeholder"),
+          placeholder: props.filesOnly()
+            ? palette.language.t("session.header.searchFiles")
+            : palette.language.t("palette.search.placeholder"),
           autofocus: true,
           hideIcon: true,
         }}
-        emptyMessage={language.t("palette.empty")}
-        loadingMessage={language.t("common.loading")}
+        emptyMessage={palette.language.t("palette.empty")}
+        loadingMessage={palette.language.t("common.loading")}
         items={items}
         key={(item) => item.id}
         filterKeys={["title", "description", "category"]}
         skipFilter={(item) => item.type === "file"}
         groupBy={grouped() ? (item) => item.category : () => ""}
-        onMove={handleMove}
-        onSelect={handleSelect}
+        onMove={(item: CommandPaletteEntry | undefined) => palette.highlight(item)}
+        onSelect={(item: CommandPaletteEntry | undefined) => palette.select(item)}
       >
         {(item) => (
           <Switch
@@ -452,7 +152,7 @@ export function DialogSelectFile(props: { mode?: DialogSelectFileMode; onOpenFil
                   </Show>
                 </div>
                 <Show when={item.keybind}>
-                  <Keybind class="rounded-[4px]">{formatKeybind(item.keybind ?? "", language.t)}</Keybind>
+                  <Keybind class="rounded-[4px]">{formatKeybind(item.keybind ?? "", palette.language.t)}</Keybind>
                 </Show>
               </div>
             </Match>
@@ -479,7 +179,7 @@ export function DialogSelectFile(props: { mode?: DialogSelectFileMode; onOpenFil
                 </div>
                 <Show when={item.updated}>
                   <span class="text-12-regular text-text-weak whitespace-nowrap ml-2">
-                    {getRelativeTime(new Date(item.updated!).toISOString(), language.t)}
+                    {getRelativeTime(new Date(item.updated!).toISOString(), palette.language.t)}
                   </span>
                 </Show>
               </div>

packages/app/src/components/dialog-select-model-search.test.ts

@@ -0,0 +1,19 @@
+import { describe, expect, test } from "bun:test"
+import { matchesModelSearch } from "./dialog-select-model-search"
+
+describe("matchesModelSearch", () => {
+  test("matches model names across separators", () => {
+    expect(matchesModelSearch("gpt 5", ["GPT-5.5"])).toBe(true)
+    expect(matchesModelSearch("gpt-5", ["GPT-5.5"])).toBe(true)
+    expect(matchesModelSearch("gpt5", ["GPT-5.5"])).toBe(true)
+  })
+
+  test("matches any searchable model field", () => {
+    expect(matchesModelSearch("open ai", ["GPT-5.5", "gpt-5.5", "OpenAI"])).toBe(true)
+    expect(matchesModelSearch("gpt 5", ["GPT-5.5", "gpt-5.5", "OpenAI"])).toBe(true)
+  })
+
+  test("does not match unrelated searches", () => {
+    expect(matchesModelSearch("claude", ["GPT-5.5", "gpt-5.5", "OpenAI"])).toBe(false)
+  })
+})

packages/app/src/components/dialog-select-model-search.ts

@@ -0,0 +1,18 @@
+export const normalizeModelSearch = (value: string) =>
+  value
+    .toLowerCase()
+    .replace(/[^\p{Letter}\p{Number}]+/gu, " ")
+    .trim()
+    .replace(/\s+/g, " ")
+
+export const compactModelSearch = (value: string) => normalizeModelSearch(value).replaceAll(" ", "")
+
+export const matchesModelSearch = (query: string, values: string[]) => {
+  const search = normalizeModelSearch(query)
+  if (!search) return true
+
+  const compactSearch = compactModelSearch(query)
+  return values.some(
+    (value) => normalizeModelSearch(value).includes(search) || compactModelSearch(value).includes(compactSearch),
+  )
+}

packages/app/src/components/dialog-select-model-unpaid.tsx

@@ -22,17 +22,16 @@ export const DialogSelectModelUnpaid: Component<{ model?: ModelState }> = (props
   const providers = useProviders(directory)
   const language = useLanguage()
 
-  const connect = (provider: string) => {
+  const openProviders = (provider?: string) => {
     void import("./dialog-connect-provider").then((x) => {
-      dialog.show(() => <x.DialogConnectProvider provider={provider} directory={directory} />)
+      const controller = x.useProviderConnectController()
+      controller.select(provider)
+      void dialog.show(() => <x.DialogConnectProvider controller={controller} directory={directory} />)
     })
   }
 
-  const all = () => {
-    void import("./dialog-select-provider").then((x) => {
-      dialog.show(() => <x.DialogSelectProvider directory={directory} />)
-    })
-  }
+  const connect = (provider: string) => openProviders(provider)
+  const all = () => openProviders()
 
   let listRef: ListRef | undefined
   const handleKeyDown = (e: KeyboardEvent) => {

packages/app/src/components/dialog-select-model.tsx

@@ -1,23 +1,57 @@
 import { Popover as Kobalte } from "@kobalte/core/popover"
-import { Component, ComponentProps, createMemo, JSX, Show, ValidComponent } from "solid-js"
+import {
+  Component,
+  ComponentProps,
+  createEffect,
+  createMemo,
+  For,
+  JSX,
+  onCleanup,
+  Show,
+  ValidComponent,
+} from "solid-js"
 import { createStore } from "solid-js/store"
 import { useLocal } from "@/context/local"
 import { useDialog } from "@opencode-ai/ui/context/dialog"
 import { popularProviders } from "@/hooks/use-providers"
 import { Button } from "@opencode-ai/ui/button"
 import { IconButton } from "@opencode-ai/ui/icon-button"
+import { ScrollView } from "@opencode-ai/ui/scroll-view"
 import { Tag } from "@opencode-ai/ui/tag"
 import { Dialog } from "@opencode-ai/ui/dialog"
 import { List } from "@opencode-ai/ui/list"
 import { Tooltip } from "@opencode-ai/ui/tooltip"
+import { Icon } from "@opencode-ai/ui/v2/icon"
+import { Tag as TagV2 } from "@opencode-ai/ui/v2/badge-v2"
+import { MenuV2 } from "@opencode-ai/ui/v2/menu-v2"
+import { TooltipV2 } from "@opencode-ai/ui/v2/tooltip-v2"
 import { ModelTooltip } from "./model-tooltip"
 import { useLanguage } from "@/context/language"
 import { decode64 } from "@/utils/base64"
+import { handleDocumentSearchKeydown } from "@/utils/search-keydown"
+import { createEventListener } from "@solid-primitives/event-listener"
+import { matchesModelSearch } from "./dialog-select-model-search"
 
 const isFree = (provider: string, cost: { input: number } | undefined) =>
   provider === "opencode" && (!cost || cost.input === 0)
 
 type ModelState = ReturnType<typeof useLocal>["model"]
+type ModelItem = ReturnType<ModelState["list"]>[number]
+
+const modelKey = (model: ModelItem) => `${model.provider.id}:${model.id}`
+const manageKey = "action:manage"
+
+const sortModelGroups = (a: { category: string; items: ModelItem[] }, b: { category: string; items: ModelItem[] }) => {
+  const aIndex = popularProviders.indexOf(a.category)
+  const bIndex = popularProviders.indexOf(b.category)
+  const aPopular = aIndex >= 0
+  const bPopular = bIndex >= 0
+
+  if (aPopular && !bPopular) return -1
+  if (!aPopular && bPopular) return 1
+  if (aPopular && bPopular) return aIndex - bIndex
+  return a.items[0].provider.name.localeCompare(b.items[0].provider.name)
+}
 
 const ModelList: Component<{
   provider?: string
@@ -123,8 +157,8 @@ export function ModelSelectorPopover(props: {
 
   const handleConnectProvider = () => {
     close("provider")
-    void import("./dialog-select-provider").then((x) => {
-      dialog.show(() => <x.DialogSelectProvider directory={directory} />)
+    void import("./dialog-connect-provider").then((x) => {
+      void dialog.show(() => <x.DialogConnectProvider directory={directory} />)
     })
   }
   const language = useLanguage()
@@ -200,6 +234,285 @@ export function ModelSelectorPopover(props: {
   )
 }
 
+export function ModelSelectorPopoverV2(props: {
+  provider?: string
+  model?: ModelState
+  children?: JSX.Element
+  triggerAs?: ValidComponent
+  triggerProps?: ModelSelectorTriggerProps
+  onClose?: () => void
+}) {
+  const model = props.model ?? useLocal().model
+  const language = useLanguage()
+  const dialog = useDialog()
+  const [store, setStore] = createStore({ open: false, search: "", active: "" })
+  let searchRef: HTMLInputElement | undefined
+  let contentRef: HTMLDivElement | undefined
+  let restoreTrigger = true
+
+  const allModels = createMemo(() =>
+    model
+      .list()
+      .filter((item) => model.visible({ modelID: item.id, providerID: item.provider.id }))
+      .filter((item) => (props.provider ? item.provider.id === props.provider : true)),
+  )
+  const models = createMemo(() => {
+    const search = store.search.trim()
+    const filtered = search
+      ? allModels().filter((item) => matchesModelSearch(search, [item.name, item.id, item.provider.name]))
+      : allModels()
+
+    return [...filtered].sort((a, b) => a.name.localeCompare(b.name))
+  })
+  const groups = createMemo(() => {
+    const byProvider = new Map<string, ModelItem[]>()
+    for (const item of models()) {
+      byProvider.set(item.provider.id, [...(byProvider.get(item.provider.id) ?? []), item])
+    }
+    return Array.from(byProvider, ([category, items]) => ({ category, items })).sort(sortModelGroups)
+  })
+  const keys = () => [...models().map(modelKey), manageKey]
+  const current = () => {
+    const value = model.current()
+    return value ? `${value.provider.id}:${value.id}` : undefined
+  }
+  const initialActive = () => {
+    const selected = current()
+    const options = keys()
+    if (selected && options.includes(selected)) return selected
+    return options[0] ?? ""
+  }
+  const activeItem = () =>
+    store.active ? contentRef?.querySelector<HTMLElement>(`[data-option-key="${CSS.escape(store.active)}"]`) : undefined
+  const afterClose = (callback: () => void) => {
+    const complete = () => {
+      if (contentRef?.isConnected) {
+        requestAnimationFrame(complete)
+        return
+      }
+      requestAnimationFrame(() => requestAnimationFrame(callback))
+    }
+    requestAnimationFrame(complete)
+  }
+  const setOpen = (open: boolean) => {
+    if (open) {
+      restoreTrigger = true
+      setStore({ open: true, active: initialActive() })
+      setTimeout(() =>
+        requestAnimationFrame(() => {
+          searchRef?.focus()
+          activeItem()?.scrollIntoView({ block: "nearest" })
+        }),
+      )
+      return
+    }
+    setStore({ open: false, search: "", active: "" })
+  }
+  const select = (item: ModelItem) => {
+    model.set({ modelID: item.id, providerID: item.provider.id }, { recent: true })
+    props.onClose?.()
+  }
+  const selectModel = (item: ModelItem) => {
+    restoreTrigger = false
+    setOpen(false)
+    afterClose(() => select(item))
+  }
+  const manage = () => {
+    restoreTrigger = false
+    setOpen(false)
+    afterClose(() => {
+      void import("./dialog-manage-models").then((x) => {
+        dialog.show(() => <x.DialogManageModelsV2 />)
+      })
+    })
+  }
+  const selectActive = () => {
+    const item = models().find((item) => modelKey(item) === store.active)
+    if (item) {
+      selectModel(item)
+      return
+    }
+    if (store.active === manageKey) manage()
+  }
+  const moveActive = (delta: number) => {
+    const options = keys()
+    if (options.length === 0) return
+    const index = options.indexOf(store.active)
+    const start = index === -1 ? 0 : index
+    setStore("active", options[(start + delta + options.length) % options.length])
+    queueMicrotask(() => activeItem()?.scrollIntoView({ block: "nearest" }))
+  }
+  const setSearch = (value: string) => {
+    const search = value.trim()
+    const first = [...allModels()]
+      .sort((a, b) => a.name.localeCompare(b.name))
+      .find((item) => matchesModelSearch(search, [item.name, item.id, item.provider.name]))
+    setStore({ search: value, active: first ? modelKey(first) : manageKey })
+  }
+
+  createEffect(() => {
+    if (!store.open) return
+    createEventListener(
+      document,
+      "keydown",
+      (event: KeyboardEvent) => handleDocumentSearchKeydown(searchRef, event, store.search, setSearch),
+      true,
+    )
+  })
+
+  return (
+    <MenuV2 open={store.open} modal={false} placement="top-start" gutter={6} onOpenChange={setOpen}>
+      <MenuV2.Trigger as={props.triggerAs ?? "div"} {...props.triggerProps}>
+        {props.children}
+      </MenuV2.Trigger>
+      <MenuV2.Portal>
+        <MenuV2.Content
+          ref={(el: HTMLDivElement) => (contentRef = el)}
+          class="w-[284px] overflow-hidden rounded-md border-0 bg-v2-background-bg-layer-01 !p-0 shadow-[var(--v2-elevation-floating)] focus:outline-none"
+          onPointerDownOutside={() => (restoreTrigger = false)}
+          onFocusOutside={() => (restoreTrigger = false)}
+          onCloseAutoFocus={(event) => {
+            if (!restoreTrigger) event.preventDefault()
+          }}
+        >
+          <div class="flex flex-col p-0.5">
+            <div class="flex h-7 items-center gap-2 rounded-sm pl-3 pr-2.5 text-v2-icon-icon-muted">
+              <Icon name="magnifying-glass" size="small" class="shrink-0" />
+              <input
+                ref={(el) => (searchRef = el)}
+                value={store.search}
+                placeholder={language.t("dialog.model.search.placeholder")}
+                class="h-7 min-w-0 flex-1 border-0 bg-transparent text-[13px] font-[440] leading-5 tracking-[-0.04px] text-v2-text-text-base outline-none placeholder:text-v2-text-text-faint"
+                spellcheck={false}
+                autocorrect="off"
+                autocomplete="off"
+                autocapitalize="off"
+                onInput={(event) => setSearch(event.currentTarget.value)}
+                onKeyDown={(event) => {
+                  if (event.key === "Tab") return
+                  event.stopPropagation()
+                  if (event.key === "Escape") {
+                    event.preventDefault()
+                    restoreTrigger = false
+                    setOpen(false)
+                    afterClose(() => props.onClose?.())
+                    return
+                  }
+                  if (event.altKey || event.metaKey) return
+                  if (event.key === "ArrowDown") {
+                    event.preventDefault()
+                    moveActive(1)
+                    return
+                  }
+                  if (event.key === "ArrowUp") {
+                    event.preventDefault()
+                    moveActive(-1)
+                    return
+                  }
+                  if (event.key === "Enter" && !event.isComposing) {
+                    event.preventDefault()
+                    selectActive()
+                  }
+                }}
+              />
+              <Show when={store.search.trim()}>
+                <button
+                  type="button"
+                  class="flex size-5 items-center justify-center rounded-sm text-v2-icon-icon-muted hover:bg-v2-overlay-simple-overlay-hover"
+                  onPointerDown={(event) => event.preventDefault()}
+                  onClick={() => setSearch("")}
+                  aria-label={language.t("common.clear")}
+                >
+                  <Icon name="close" size="small" />
+                </button>
+              </Show>
+            </div>
+          </div>
+          <div class="h-px bg-v2-border-border-muted" />
+          <ScrollView data-slot="model-selector-scroll" class="max-h-[220px] min-h-0">
+            <div class="flex flex-col p-0.5 pt-0">
+              <Show
+                when={models().length > 0}
+                fallback={
+                  <div class="flex h-12 items-center px-3 text-[13px] font-[440] leading-5 tracking-[-0.04px] text-v2-text-text-faint">
+                    {language.t("dialog.model.empty")}
+                  </div>
+                }
+              >
+                <For each={groups()}>
+                  {(group) => (
+                    <MenuV2.Group>
+                      <MenuV2.GroupLabel class="gap-2 px-3">
+                        <span class="min-w-0 truncate">{group.items[0].provider.name}</span>
+                      </MenuV2.GroupLabel>
+                      <MenuV2.RadioGroup value={current()}>
+                        <For each={group.items}>
+                          {(item) => (
+                            <TooltipV2
+                              class="w-full"
+                              placement="right-start"
+                              gutter={6}
+                              openDelay={0}
+                              value={
+                                <ModelTooltip
+                                  model={item}
+                                  latest={item.latest}
+                                  free={isFree(item.provider.id, item.cost)}
+                                  v2
+                                />
+                              }
+                            >
+                              <MenuV2.RadioItem
+                                value={modelKey(item)}
+                                data-option-key={modelKey(item)}
+                                data-selected-model={current() === modelKey(item) ? true : undefined}
+                                class="scroll-my-6 w-full"
+                                classList={{ "!bg-v2-overlay-simple-overlay-hover": store.active === modelKey(item) }}
+                                onMouseEnter={() => {
+                                  setStore("active", modelKey(item))
+                                  setTimeout(() => searchRef?.focus())
+                                }}
+                                onSelect={() => selectModel(item)}
+                              >
+                                <span class="min-w-0 truncate">{item.name}</span>
+                                <Show when={isFree(item.provider.id, item.cost)}>
+                                  <TagV2 class="shrink-0">{language.t("model.tag.free")}</TagV2>
+                                </Show>
+                                <Show when={item.latest}>
+                                  <TagV2 class="shrink-0">{language.t("model.tag.latest")}</TagV2>
+                                </Show>
+                              </MenuV2.RadioItem>
+                            </TooltipV2>
+                          )}
+                        </For>
+                      </MenuV2.RadioGroup>
+                    </MenuV2.Group>
+                  )}
+                </For>
+              </Show>
+            </div>
+          </ScrollView>
+          <div class="h-px bg-v2-border-border-muted" />
+          <div class="flex flex-col p-0.5">
+            <MenuV2.Item
+              data-option-key={manageKey}
+              classList={{ "!bg-v2-overlay-simple-overlay-hover": store.active === manageKey }}
+              onMouseEnter={() => {
+                setStore("active", manageKey)
+                setTimeout(() => searchRef?.focus())
+              }}
+              onSelect={manage}
+            >
+              <Icon name="outline-sliders" size="small" />
+              <span class="min-w-0 flex-1 truncate leading-5">{language.t("dialog.model.manage")}</span>
+            </MenuV2.Item>
+          </div>
+        </MenuV2.Content>
+      </MenuV2.Portal>
+    </MenuV2>
+  )
+}
+
 export const DialogSelectModel: Component<{ provider?: string; model?: ModelState }> = (props) => {
   const dialog = useDialog()
   const language = useLanguage()
@@ -207,8 +520,8 @@ export const DialogSelectModel: Component<{ provider?: string; model?: ModelStat
   const directory = () => decode64(local.slug())
 
   const provider = () => {
-    void import("./dialog-select-provider").then((x) => {
-      dialog.show(() => <x.DialogSelectProvider directory={directory} />)
+    void import("./dialog-connect-provider").then((x) => {
+      void dialog.show(() => <x.DialogConnectProvider directory={directory} />)
     })
   }
 

packages/app/src/components/dialog-select-provider.tsx

@@ -1,87 +0,0 @@
-import { type Accessor, Component, Show } from "solid-js"
-import { useDialog } from "@opencode-ai/ui/context/dialog"
-import { popularProviders, useProviders } from "@/hooks/use-providers"
-import { Dialog } from "@opencode-ai/ui/dialog"
-import { List } from "@opencode-ai/ui/list"
-import { Tag } from "@opencode-ai/ui/tag"
-import { ProviderIcon } from "@opencode-ai/ui/provider-icon"
-import { DialogConnectProvider } from "./dialog-connect-provider"
-import { useLanguage } from "@/context/language"
-import { DialogCustomProvider } from "./dialog-custom-provider"
-
-const CUSTOM_ID = "_custom"
-
-export const DialogSelectProvider: Component<{ directory?: Accessor<string | undefined> }> = (props) => {
-  const dialog = useDialog()
-  const providers = useProviders(props.directory)
-  const language = useLanguage()
-
-  const popularGroup = () => language.t("dialog.provider.group.popular")
-  const otherGroup = () => language.t("dialog.provider.group.other")
-  const customLabel = () => language.t("settings.providers.tag.custom")
-  const note = (id: string) => {
-    if (id === "anthropic") return language.t("dialog.provider.anthropic.note")
-    if (id === "openai") return language.t("dialog.provider.openai.note")
-    if (id.startsWith("github-copilot")) return language.t("dialog.provider.copilot.note")
-    if (id === "opencode-go") return language.t("dialog.provider.opencodeGo.tagline")
-  }
-
-  return (
-    <Dialog title={language.t("command.provider.connect")} transition>
-      <List
-        class="px-3"
-        search={{ placeholder: language.t("dialog.provider.search.placeholder"), autofocus: true }}
-        emptyMessage={language.t("dialog.provider.empty")}
-        activeIcon="plus-small"
-        key={(x) => x?.id}
-        items={() => {
-          language.locale()
-          return [{ id: CUSTOM_ID, name: customLabel() }, ...providers.all().values()]
-        }}
-        filterKeys={["id", "name"]}
-        groupBy={(x) => (popularProviders.includes(x.id) ? popularGroup() : otherGroup())}
-        sortBy={(a, b) => {
-          if (a.id === CUSTOM_ID) return -1
-          if (b.id === CUSTOM_ID) return 1
-          if (popularProviders.includes(a.id) && popularProviders.includes(b.id))
-            return popularProviders.indexOf(a.id) - popularProviders.indexOf(b.id)
-          return a.name.localeCompare(b.name)
-        }}
-        sortGroupsBy={(a, b) => {
-          const popular = popularGroup()
-          if (a.category === popular && b.category !== popular) return -1
-          if (b.category === popular && a.category !== popular) return 1
-          return 0
-        }}
-        onSelect={(x) => {
-          if (!x) return
-          if (x.id === CUSTOM_ID) {
-            dialog.show(() => <DialogCustomProvider back="providers" directory={props.directory} />)
-            return
-          }
-          dialog.show(() => <DialogConnectProvider provider={x.id} directory={props.directory} />)
-        }}
-      >
-        {(i) => (
-          <div class="px-1.25 w-full flex items-center gap-x-3">
-            <ProviderIcon data-slot="list-item-extra-icon" id={i.id} />
-            <span>{i.name}</span>
-            <Show when={i.id === "opencode"}>
-              <div class="text-14-regular text-text-weak">{language.t("dialog.provider.opencode.tagline")}</div>
-            </Show>
-            <Show when={i.id === CUSTOM_ID}>
-              <Tag>{language.t("settings.providers.tag.custom")}</Tag>
-            </Show>
-            <Show when={i.id === "opencode"}>
-              <Tag>{language.t("dialog.provider.tag.recommended")}</Tag>
-            </Show>
-            <Show when={note(i.id)}>{(value) => <div class="text-14-regular text-text-weak">{value()}</div>}</Show>
-            <Show when={i.id === "opencode-go"}>
-              <Tag>{language.t("dialog.provider.tag.recommended")}</Tag>
-            </Show>
-          </div>
-        )}
-      </List>
-    </Dialog>
-  )
-}

packages/app/src/components/dialog-settings.tsx

@@ -1,22 +1,35 @@
-import { Component } from "solid-js"
+import { Component, createSignal, startTransition } from "solid-js"
 import { Dialog } from "@opencode-ai/ui/dialog"
 import { Tabs } from "@opencode-ai/ui/tabs"
 import { Icon } from "@opencode-ai/ui/icon"
 import { useLanguage } from "@/context/language"
 import { usePlatform } from "@/context/platform"
+import { useDialog } from "@opencode-ai/ui/context/dialog"
 import { SettingsGeneral } from "./settings-general"
 import { SettingsKeybinds } from "./settings-keybinds"
 import { SettingsProviders } from "./settings-providers"
 import { SettingsModels } from "./settings-models"
 import { SettingsServers } from "./settings-servers"
 
-export const DialogSettings: Component = () => {
+export const DialogSettings: Component<{ defaultValue?: string }> = (props) => {
   const language = useLanguage()
   const platform = usePlatform()
+  const dialog = useDialog()
+  const [tab, setTab] = createSignal(props.defaultValue ?? "general")
+
+  const showProviders = () => {
+    void dialog.show(() => <DialogSettings defaultValue="providers" />)
+  }
 
   return (
     <Dialog size="x-large" transition>
-      <Tabs orientation="vertical" variant="settings" defaultValue="general" class="h-full settings-dialog">
+      <Tabs
+        orientation="vertical"
+        variant="settings"
+        value={tab()}
+        onChange={(value) => void startTransition(() => setTab(value))}
+        class="h-full settings-dialog"
+      >
         <Tabs.List>
           <div class="flex flex-col justify-between h-full w-full gap-4">
             <div class="flex flex-col gap-3 w-full pt-3">
@@ -70,7 +83,7 @@ export const DialogSettings: Component = () => {
           <SettingsServers />
         </Tabs.Content>
         <Tabs.Content value="providers" class="no-scrollbar">
-          <SettingsProviders />
+          <SettingsProviders onBack={showProviders} />
         </Tabs.Content>
         <Tabs.Content value="models" class="no-scrollbar">
           <SettingsModels />

packages/app/src/components/file-tree-v2-model.test.ts

@@ -0,0 +1,46 @@
+import { describe, expect, test } from "bun:test"
+import { buildFileTreeV2Model, flattenFileTreeV2 } from "./file-tree-v2-model"
+
+describe("file tree v2 model", () => {
+  test("builds sorted depth-first rows", () => {
+    const model = buildFileTreeV2Model(["src/z.ts", "src/lib/b.ts", "src/lib/a.ts", "README.md", "docs/guide.md"])
+
+    expect(model.total).toBe(8)
+    expect(flattenFileTreeV2(model, () => true).map((row) => [row.node.path, row.node.type, row.level])).toEqual([
+      ["docs", "directory", 0],
+      ["docs/guide.md", "file", 1],
+      ["src", "directory", 0],
+      ["src/lib", "directory", 1],
+      ["src/lib/a.ts", "file", 2],
+      ["src/lib/b.ts", "file", 2],
+      ["src/z.ts", "file", 1],
+      ["README.md", "file", 0],
+    ])
+  })
+
+  test("omits descendants of collapsed directories", () => {
+    const model = buildFileTreeV2Model(["src/lib/a.ts", "src/z.ts"])
+
+    expect(flattenFileTreeV2(model, (path) => path !== "src/lib").map((row) => row.node.path)).toEqual([
+      "src",
+      "src/lib",
+      "src/z.ts",
+    ])
+  })
+
+  test("normalizes separators and duplicate paths", () => {
+    const model = buildFileTreeV2Model(["src\\lib\\a.ts", "src/lib/a.ts", "/src//lib/b.ts/"])
+    const rows = flattenFileTreeV2(model, () => true)
+
+    expect(model.total).toBe(4)
+    expect(rows.map((row) => row.node.path)).toEqual(["src", "src/lib", "src/lib/a.ts", "src/lib/b.ts"])
+    expect(rows.find((row) => row.node.path === "src/lib/a.ts")?.node.originalPath).toBe("src\\lib\\a.ts")
+  })
+
+  test("supports paths deeper than the legacy recursion limit", () => {
+    const file = `${Array.from({ length: 130 }, (_, index) => `dir-${index}`).join("/")}/file.ts`
+    const model = buildFileTreeV2Model([file])
+
+    expect(flattenFileTreeV2(model, () => true)).toHaveLength(131)
+  })
+})

packages/app/src/components/file-tree-v2-model.ts

@@ -0,0 +1,77 @@
+import type { FileNode } from "@opencode-ai/sdk/v2"
+
+export type FileTreeV2Model = {
+  children: ReadonlyMap<string, readonly FileTreeV2Node[]>
+  total: number
+}
+
+export type FileTreeV2Node = FileNode & { originalPath: string }
+
+export type FileTreeV2Row = {
+  node: FileTreeV2Node
+  level: number
+}
+
+export function normalizeFileTreeV2Path(value: string) {
+  return value
+    .replaceAll("\\", "/")
+    .replace(/^\/+|\/+$/g, "")
+    .replace(/\/{2,}/g, "/")
+}
+
+export function buildFileTreeV2Model(paths: readonly string[]): FileTreeV2Model {
+  const nodes = new Map<string, FileTreeV2Node>()
+
+  paths.forEach((value) => {
+    const file = normalizeFileTreeV2Path(value)
+    if (!file) return
+
+    const parts = file.split("/")
+    parts.forEach((name, index) => {
+      const path = parts.slice(0, index + 1).join("/")
+      if (nodes.has(path)) return
+      nodes.set(path, {
+        name,
+        path,
+        absolute: path,
+        type: index === parts.length - 1 ? "file" : "directory",
+        ignored: false,
+        originalPath: index === parts.length - 1 ? value : path,
+      })
+    })
+  })
+
+  const children = new Map<string, FileTreeV2Node[]>()
+  nodes.forEach((node) => {
+    const index = node.path.lastIndexOf("/")
+    const parent = index === -1 ? "" : node.path.slice(0, index)
+    const list = children.get(parent)
+    if (list) list.push(node)
+    else children.set(parent, [node])
+  })
+  children.forEach((nodes) =>
+    nodes.sort((a, b) => {
+      if (a.type !== b.type) return a.type === "directory" ? -1 : 1
+      return a.name.localeCompare(b.name)
+    }),
+  )
+
+  return { children, total: nodes.size }
+}
+
+export function flattenFileTreeV2(model: FileTreeV2Model, expanded: (path: string) => boolean) {
+  const rows: FileTreeV2Row[] = []
+  const stack = (model.children.get("") ?? []).toReversed().map((node) => ({ node, level: 0 }))
+
+  while (stack.length > 0) {
+    const row = stack.pop()!
+    rows.push(row)
+    if (row.node.type !== "directory" || !expanded(row.node.path)) continue
+    const children = model.children.get(row.node.path) ?? []
+    for (let index = children.length - 1; index >= 0; index--) {
+      stack.push({ node: children[index]!, level: row.level + 1 })
+    }
+  }
+
+  return rows
+}

packages/app/src/components/file-tree-v2.tsx

@@ -0,0 +1,268 @@
+import { useFile } from "@/context/file"
+import { FileIcon } from "@opencode-ai/ui/file-icon"
+import "@opencode-ai/ui/v2/file-tree-v2.css"
+import {
+  createEffect,
+  createMemo,
+  createSignal,
+  For,
+  Show,
+  splitProps,
+  type ComponentProps,
+  type ParentProps,
+} from "solid-js"
+import { Dynamic } from "solid-js/web"
+import type { FileNode } from "@opencode-ai/sdk/v2"
+import { Icon } from "@opencode-ai/ui/v2/icon"
+import { pathToFileUrl, withFileDragImage, type Kind } from "@/components/file-tree"
+import { createVirtualizer, defaultRangeExtractor } from "@tanstack/solid-virtual"
+import { buildFileTreeV2Model, flattenFileTreeV2, normalizeFileTreeV2Path } from "@/components/file-tree-v2-model"
+import { virtualScrollElement } from "@/components/virtual-scroll-element"
+
+export type { Kind } from "@/components/file-tree"
+
+const INDENT_STEP = 16
+
+function rowPaddingLeft(level: number, type: FileNode["type"]) {
+  if (type === "directory") return 8 + level * INDENT_STEP
+  if (level === 0) return 8
+  return 8 + level * INDENT_STEP - INDENT_STEP
+}
+
+function guideLineLeft(level: number) {
+  return rowPaddingLeft(level, "directory") + 8
+}
+
+export const kindLabel = (kind: Kind) => {
+  if (kind === "add") return "A"
+  if (kind === "del") return "D"
+  return ""
+}
+
+export const kindChange = (kind: Kind) => {
+  if (kind === "add") return "added"
+  if (kind === "del") return "deleted"
+  return "modified"
+}
+
+const FileTreeNodeV2 = (
+  p: ParentProps &
+    ComponentProps<"div"> &
+    ComponentProps<"button"> & {
+      node: FileNode
+      level: number
+      active?: string
+      draggable: boolean
+      kinds?: ReadonlyMap<string, Kind>
+      as?: "div" | "button"
+    },
+) => {
+  const [local, rest] = splitProps(p, [
+    "node",
+    "level",
+    "active",
+    "draggable",
+    "kinds",
+    "as",
+    "children",
+    "class",
+    "classList",
+  ])
+  const kind = () => local.kinds?.get(local.node.path)
+
+  return (
+    <Dynamic
+      component={local.as ?? "div"}
+      data-slot="file-tree-v2-row"
+      data-path={local.node.path}
+      data-selected={local.node.path === local.active ? "" : undefined}
+      data-ignored={local.node.ignored ? "" : undefined}
+      classList={{
+        ...local.classList,
+        [local.class ?? ""]: !!local.class,
+      }}
+      style={`padding-left: ${rowPaddingLeft(local.level, local.node.type)}px`}
+      draggable={local.draggable}
+      onDragStart={(event: DragEvent) => {
+        if (!local.draggable) return
+        event.dataTransfer?.setData("text/plain", `file:${local.node.path}`)
+        event.dataTransfer?.setData("text/uri-list", pathToFileUrl(local.node.path))
+        if (event.dataTransfer) event.dataTransfer.effectAllowed = "copy"
+        withFileDragImage(event)
+      }}
+      {...rest}
+    >
+      {local.children}
+      <span class="flex-1 min-w-0 text-12-medium whitespace-nowrap truncate">{local.node.name}</span>
+      {(() => {
+        const value = kind()
+        if (!value || local.node.type !== "file") return null
+        return (
+          <span data-slot="file-tree-v2-change" data-change={kindChange(value)}>
+            {kindLabel(value)}
+          </span>
+        )
+      })()}
+    </Dynamic>
+  )
+}
+
+function GuideLines(props: { level: number }) {
+  return (
+    <For each={Array.from({ length: props.level })}>
+      {(_, index) => (
+        <div
+          class="absolute top-0 bottom-0 w-px pointer-events-none bg-border-weak-base opacity-0 group-hover/file-tree-v2:opacity-50"
+          style={`left: ${guideLineLeft(index())}px`}
+        />
+      )}
+    </For>
+  )
+}
+
+export default function FileTreeV2(props: {
+  active?: string
+  allowed?: readonly string[]
+  kinds?: ReadonlyMap<string, Kind>
+  draggable?: boolean
+  onFileClick?: (file: FileNode) => void
+}) {
+  const file = useFile()
+  const draggable = () => props.draggable ?? true
+  const active = () => normalizeFileTreeV2Path(props.active ?? "")
+  const model = createMemo(() => buildFileTreeV2Model(props.allowed ?? []))
+  const rows = createMemo(() => flattenFileTreeV2(model(), (path) => file.tree.state(path)?.expanded ?? true))
+  const [root, setRoot] = createSignal<HTMLDivElement>()
+  const [focused, setFocused] = createSignal<string>()
+  const virtualizer = createVirtualizer<HTMLDivElement, HTMLDivElement>({
+    get count() {
+      return rows().length
+    },
+    getScrollElement: () => virtualScrollElement(root()),
+    initialRect: { width: 0, height: 600 },
+    estimateSize: () => 28,
+    gap: 2,
+    overscan: 10,
+    get getItemKey() {
+      const current = rows()
+      return (index: number) => current[index]?.node.path ?? index
+    },
+    rangeExtractor: (range) => {
+      const indexes = defaultRangeExtractor(range)
+      const path = focused()
+      const index = path ? rows().findIndex((row) => row.node.path === path) : -1
+      if (index < 0 || indexes.includes(index)) return indexes
+      return [...indexes, index].sort((a, b) => a - b)
+    },
+  })
+  createEffect(() => {
+    const path = active()
+    if (!path) return
+    const index = rows().findIndex((row) => row.node.path === path)
+    if (index < 0) return
+    queueMicrotask(() => {
+      if (virtualizer.range && index >= virtualizer.range.startIndex && index <= virtualizer.range.endIndex) return
+      virtualizer.scrollToIndex(index, { align: "auto" })
+    })
+  })
+  const rowByKey = createMemo(() => new Map(rows().map((row) => [row.node.path, row] as const)))
+  const virtualItemByKey = createMemo(
+    () => new Map(virtualizer.getVirtualItems().map((item) => [item.key, item] as const)),
+  )
+  const virtualRowKeys = createMemo(() => virtualizer.getVirtualItems().map((item) => item.key))
+
+  return (
+    <div
+      ref={setRoot}
+      data-component="file-tree-v2"
+      data-total-rows={model().total}
+      class="group/file-tree-v2"
+      style={{ position: "relative", height: `${virtualizer.getTotalSize()}px` }}
+    >
+      <For each={virtualRowKeys()}>
+        {(key) => (
+          <Show when={virtualItemByKey().get(key)}>
+            {(item) => (
+              <div
+                style={{
+                  position: "absolute",
+                  top: "0",
+                  left: "0",
+                  width: "100%",
+                  height: `${item().size}px`,
+                  transform: `translateY(${item().start}px)`,
+                }}
+              >
+                <Show when={rowByKey().get(key as string)}>
+                  {(row) => (
+                    <Show
+                      when={row().node.type === "directory"}
+                      fallback={
+                        <FileTreeNodeV2
+                          node={row().node}
+                          level={row().level}
+                          active={active()}
+                          draggable={draggable()}
+                          kinds={props.kinds}
+                          as="button"
+                          type="button"
+                          class="relative"
+                          onFocus={() => setFocused(row().node.path)}
+                          onBlur={() => setFocused(undefined)}
+                          onClick={() =>
+                            props.onFileClick?.({
+                              ...row().node,
+                              path: row().node.originalPath,
+                              absolute: row().node.originalPath,
+                            })
+                          }
+                        >
+                          <GuideLines level={row().level} />
+                          <Show when={row().level > 0}>
+                            <div class="w-4 shrink-0" />
+                          </Show>
+                          <span class="filetree-iconpair size-4">
+                            <FileIcon node={row().node} class="size-4 filetree-icon filetree-icon--color" />
+                            <FileIcon node={row().node} class="size-4 filetree-icon filetree-icon--mono" mono />
+                          </span>
+                        </FileTreeNodeV2>
+                      }
+                    >
+                      <FileTreeNodeV2
+                        node={row().node}
+                        level={row().level}
+                        active={active()}
+                        draggable={draggable()}
+                        kinds={props.kinds}
+                        as="button"
+                        type="button"
+                        class="relative"
+                        onFocus={() => setFocused(row().node.path)}
+                        onBlur={() => setFocused(undefined)}
+                        aria-expanded={file.tree.state(row().node.path)?.expanded ?? true}
+                        onClick={() =>
+                          file.tree.state(row().node.path)?.expanded === false
+                            ? file.tree.expand(row().node.path, { list: false })
+                            : file.tree.collapse(row().node.path)
+                        }
+                      >
+                        <GuideLines level={row().level} />
+                        <div
+                          data-slot="file-tree-v2-chevron"
+                          data-expanded={file.tree.state(row().node.path)?.expanded === false ? undefined : ""}
+                          class="size-4 flex items-center justify-center"
+                        >
+                          <Icon name="chevron-down" />
+                        </div>
+                      </FileTreeNodeV2>
+                    </Show>
+                  )}
+                </Show>
+              </div>
+            )}
+          </Show>
+        )}
+      </For>
+    </div>
+  )
+}

packages/app/src/components/file-tree.tsx

@@ -21,13 +21,13 @@ import type { FileNode } from "@opencode-ai/sdk/v2"
 
 const MAX_DEPTH = 128
 
-function pathToFileUrl(filepath: string): string {
+export function pathToFileUrl(filepath: string): string {
   return `file://${encodeFilePath(filepath)}`
 }
 
-type Kind = "add" | "del" | "mix"
+export type Kind = "add" | "del" | "mix"
 
-type Filter = {
+export type Filter = {
   files: Set<string>
   dirs: Set<string>
 }
@@ -78,7 +78,7 @@ const kindDotColor = (kind: Kind) => {
   return "background-color: var(--icon-diff-modified-base)"
 }
 
-const visibleKind = (node: FileNode, kinds?: ReadonlyMap<string, Kind>, marks?: Set<string>) => {
+export const visibleKind = (node: FileNode, kinds?: ReadonlyMap<string, Kind>, marks?: Set<string>) => {
   const kind = kinds?.get(node.path)
   if (!kind) return
   if (!marks?.has(node.path)) return
@@ -99,7 +99,7 @@ const buildDragImage = (target: HTMLElement) => {
   return image
 }
 
-const withFileDragImage = (event: DragEvent) => {
+export const withFileDragImage = (event: DragEvent) => {
   const image = buildDragImage(event.currentTarget as HTMLElement)
   if (!image) return
   document.body.appendChild(image)

packages/app/src/components/model-tooltip.tsx

@@ -1,4 +1,4 @@
-import { Show, type Component } from "solid-js"
+import { Show, type Component, type JSX } from "solid-js"
 import { useLanguage } from "@/context/language"
 
 type InputKey = "text" | "image" | "audio" | "video" | "pdf"
@@ -23,7 +23,18 @@ type ModelInfo = {
   }
 }
 
-export const ModelTooltip: Component<{ model: ModelInfo; latest?: boolean; free?: boolean }> = (props) => {
+function ModelTooltipRow(props: { name: JSX.Element; value: JSX.Element }) {
+  return (
+    <div class="flex min-w-0 items-center gap-4">
+      <span class="shrink-0 text-v2-text-text-muted">{props.name}</span>
+      <span class="ml-auto min-w-0 truncate text-right text-v2-text-text-base">{props.value}</span>
+    </div>
+  )
+}
+
+export const ModelTooltip: Component<{ model: ModelInfo; latest?: boolean; free?: boolean; v2?: boolean }> = (
+  props,
+) => {
   const language = useLanguage()
   const sourceName = (model: ModelInfo) => {
     const value = `${model.id} ${model.name}`.toLowerCase()
@@ -51,6 +62,13 @@ export const ModelTooltip: Component<{ model: ModelInfo; latest?: boolean; free?
     const suffix = tags.length ? ` (${tags.join(", ")})` : ""
     return `${sourceName(props.model)} ${props.model.name}${suffix}`
   }
+  const name = () => {
+    const tags: Array<string> = []
+    if (props.latest) tags.push(language.t("model.tag.latest"))
+    if (props.free) tags.push(language.t("model.tag.free"))
+    const suffix = tags.length ? ` (${tags.join(", ")})` : ""
+    return `${props.model.name}${suffix}`
+  }
   const inputs = () => {
     if (props.model.capabilities) {
       const input = props.model.capabilities.input
@@ -73,6 +91,21 @@ export const ModelTooltip: Component<{ model: ModelInfo; latest?: boolean; free?
       : language.t("model.tooltip.reasoning.none")
   }
   const context = () => language.t("model.tooltip.context", { limit: props.model.limit.context.toLocaleString() })
+  const contextLimit = () => props.model.limit.context.toLocaleString(language.intl())
+
+  if (props.v2) {
+    return (
+      <div class="flex w-[180px] flex-col gap-2">
+        <ModelTooltipRow name={language.t("model.tooltip.model")} value={name()} />
+        <ModelTooltipRow name={language.t("model.tooltip.provider")} value={props.model.provider.name} />
+        <Show when={inputs()}>
+          {(value) => <ModelTooltipRow name={language.t("model.tooltip.inputs")} value={value()} />}
+        </Show>
+        <ModelTooltipRow name={language.t("model.tooltip.reasoning")} value={reasoning()} />
+        <ModelTooltipRow name={language.t("model.tooltip.context.label")} value={contextLimit()} />
+      </div>
+    )
+  }
 
   return (
     <div class="flex flex-col gap-1 py-1">

packages/app/src/components/prompt-input.tsx

@@ -36,12 +36,14 @@ import { DockShellForm, DockTray } from "@opencode-ai/ui/dock-surface"
 import { Icon } from "@opencode-ai/ui/icon"
 import { ProviderIcon } from "@opencode-ai/ui/provider-icon"
 import { Tooltip, TooltipKeybind } from "@opencode-ai/ui/tooltip"
+import { ButtonV2 } from "@opencode-ai/ui/v2/button-v2"
 import { KeybindV2 } from "@opencode-ai/ui/v2/keybind-v2"
+import { MenuV2 } from "@opencode-ai/ui/v2/menu-v2"
 import { TooltipV2 } from "@opencode-ai/ui/v2/tooltip-v2"
 import { IconButton } from "@opencode-ai/ui/icon-button"
 import { Select } from "@opencode-ai/ui/select"
 import { useDialog } from "@opencode-ai/ui/context/dialog"
-import { ModelSelectorPopover } from "@/components/dialog-select-model"
+import { ModelSelectorPopover, ModelSelectorPopoverV2 } from "@/components/dialog-select-model"
 import { useCommand } from "@/context/command"
 import { Persist, persisted } from "@/utils/persist"
 import { usePermission } from "@/context/permission"
@@ -69,6 +71,7 @@ import { promptPlaceholder } from "./prompt-input/placeholder"
 import { createPromptInputTransientState } from "./prompt-input/transient-state"
 import { showToast } from "@/utils/toast"
 import { ImagePreview } from "@opencode-ai/ui/image-preview"
+import type { ReferenceInfo } from "@opencode-ai/sdk/v2/client"
 
 export type PromptInputState = ReturnType<typeof usePrompt>
 
@@ -215,6 +218,8 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
   let fileInputRef: HTMLInputElement | undefined
   let scrollRef!: HTMLDivElement
   let slashPopoverRef!: HTMLDivElement
+  let restoreEndOnFocus = true
+  let savedCursor: number | null = null
 
   const mirror = { input: false }
   const inset = 56
@@ -587,13 +592,23 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
 
   const restoreFocus = () => {
     requestAnimationFrame(() => {
-      const cursor = prompt.cursor() ?? promptLength(prompt.current())
+      const cursor = savedCursor ?? prompt.cursor() ?? promptLength(prompt.current())
       editorRef.focus()
       setCursorPosition(editorRef, cursor)
       queueScroll()
     })
   }
 
+  const handleFocus = () => {
+    if (!restoreEndOnFocus) return
+    restoreEndOnFocus = false
+    requestAnimationFrame(() => {
+      if (document.activeElement !== editorRef) return
+      setCursorPosition(editorRef, prompt.cursor() ?? promptLength(prompt.current()))
+      queueScroll()
+    })
+  }
+
   const renderEditorWithCursor = (parts: Prompt) => {
     const cursor = currentCursor()
     renderEditor(parts)
@@ -614,6 +629,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
   const isImeComposing = (event: KeyboardEvent) => event.isComposing || composing() || event.keyCode === 229
 
   const handleBlur = () => {
+    savedCursor = currentCursor()
     closePopover()
     setComposing(false)
   }
@@ -630,24 +646,89 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
     })
   }
 
+  const referenceDescription = (reference: ReferenceInfo) =>
+    reference.source.type === "git" ? reference.source.repository : reference.source.path
+
+  const referenceList = createMemo(() =>
+    sync()
+      .data.reference.filter((reference) => !reference.hidden)
+      .map(
+        (reference): AtOption => ({
+          type: "reference",
+          name: reference.name,
+          path: reference.path,
+          display: reference.name,
+          description: reference.description ?? referenceDescription(reference),
+        }),
+      ),
+  )
+
   const agentList = createMemo(() =>
     props.controls.agents.available
       .filter((agent) => !agent.hidden && agent.mode !== "primary")
       .map((agent): AtOption => ({ type: "agent", name: agent.name, display: agent.name })),
   )
 
+  const mcpResourceList = createMemo(() =>
+    Object.values(sync().data.mcp_resource).map(
+      (resource): AtOption => ({
+        type: "resource",
+        name: resource.name,
+        uri: resource.uri,
+        client: resource.client,
+        display: resource.name,
+        description: resource.description,
+        mime: resource.mimeType,
+      }),
+    ),
+  )
+
   const handleAtSelect = (option: AtOption | undefined) => {
     if (!option) return
     if (option.type === "agent") {
       addPart({ type: "agent", name: option.name, content: "@" + option.name, start: 0, end: 0 })
-    } else {
-      addPart({ type: "file", path: option.path, content: "@" + option.path, start: 0, end: 0 })
+      return
     }
+    if (option.type === "reference") {
+      addPart({
+        type: "file",
+        path: option.path,
+        content: "@" + option.name,
+        start: 0,
+        end: 0,
+        mime: "application/x-directory",
+        filename: option.name,
+      })
+      return
+    }
+    if (option.type === "resource") {
+      addPart({
+        type: "file",
+        path: option.uri,
+        content: "@" + option.name,
+        start: 0,
+        end: 0,
+        mime: option.mime ?? "text/plain",
+        filename: option.name,
+        url: option.uri,
+        source: {
+          type: "resource",
+          text: { value: "@" + option.name, start: 0, end: 0 },
+          clientName: option.client,
+          uri: option.uri,
+        },
+      })
+      return
+    }
+    addPart({ type: "file", path: option.path, content: "@" + option.path, start: 0, end: 0 })
   }
 
   const atKey = (x: AtOption | undefined) => {
     if (!x) return ""
-    return x.type === "agent" ? `agent:${x.name}` : `file:${x.path}`
+    if (x.type === "agent") return `agent:${x.name}`
+    if (x.type === "reference") return `reference:${x.name}`
+    if (x.type === "resource") return `resource:${x.client}:${x.uri}`
+    return `file:${x.path}`
   }
 
   const {
@@ -658,30 +739,36 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
     onKeyDown: atOnKeyDown,
   } = useFilteredList<AtOption>({
     items: async (query) => {
+      const references = referenceList()
       const agents = agentList()
+      const mcpResources = mcpResourceList()
       const open = recent()
       const seen = new Set(open)
       const pinned: AtOption[] = open.map((path) => ({ type: "file", path, display: path, recent: true }))
-      if (!query.trim()) return [...agents, ...pinned]
+      if (!query.trim()) return [...references, ...agents, ...mcpResources, ...pinned]
       const paths = await files.searchFilesAndDirectories(query)
       const fileOptions: AtOption[] = paths
         .filter((path) => !seen.has(path))
         .map((path) => ({ type: "file", path, display: path }))
-      return [...agents, ...pinned, ...fileOptions]
+      return [...references, ...agents, ...mcpResources, ...pinned, ...fileOptions]
     },
     key: atKey,
     filterKeys: ["display"],
     skipFilter: (item) => item.type === "file" && !item.recent,
     groupBy: (item) => {
+      if (item.type === "reference") return "reference"
       if (item.type === "agent") return "agent"
+      if (item.type === "resource") return "resource"
       if (item.recent) return "recent"
       return "file"
     },
     sortGroupsBy: (a, b) => {
       const rank = (category: string) => {
-        if (category === "agent") return 0
-        if (category === "recent") return 1
-        return 2
+        if (category === "reference") return 0
+        if (category === "agent") return 1
+        if (category === "resource") return 2
+        if (category === "recent") return 3
+        return 4
       }
       return rank(a.category) - rank(b.category)
     },
@@ -747,7 +834,17 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
     const pill = document.createElement("span")
     pill.textContent = part.content
     pill.setAttribute("data-type", part.type)
-    if (part.type === "file") pill.setAttribute("data-path", part.path)
+    if (part.type === "file") {
+      pill.setAttribute("data-path", part.path)
+      if (part.mime) pill.setAttribute("data-mime", part.mime)
+      if (part.filename) pill.setAttribute("data-filename", part.filename)
+      if (part.url) pill.setAttribute("data-url", part.url)
+      if (part.source?.type === "resource") {
+        pill.setAttribute("data-source-type", part.source.type)
+        pill.setAttribute("data-source-client-name", part.source.clientName)
+        pill.setAttribute("data-source-uri", part.source.uri)
+      }
+    }
     if (part.type === "agent") pill.setAttribute("data-name", part.name)
     pill.setAttribute("contenteditable", "false")
     pill.style.userSelect = "text"
@@ -792,8 +889,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
     }
   }
 
-  // Auto-scroll active command into view when navigating with keyboard
-  createEffect(() => {
+  const scrollSlashActiveIntoView = () => {
     const activeId = slashActive()
     if (!activeId || !slashPopoverRef) return
 
@@ -801,7 +897,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
       const element = slashPopoverRef.querySelector(`[data-slash-id="${activeId}"]`)
       element?.scrollIntoView({ block: "nearest", behavior: "smooth" })
     })
-  })
+  }
   const selectPopoverActive = () => {
     if (store.popover === "at") {
       const items = atFlat()
@@ -863,12 +959,29 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
 
     const pushFile = (file: HTMLElement) => {
       const content = file.textContent ?? ""
+      const source =
+        file.dataset.sourceType === "resource" && file.dataset.sourceClientName && file.dataset.sourceUri
+          ? {
+              type: "resource" as const,
+              text: {
+                value: content,
+                start: position,
+                end: position + content.length,
+              },
+              clientName: file.dataset.sourceClientName,
+              uri: file.dataset.sourceUri,
+            }
+          : undefined
       parts.push({
         type: "file",
         path: file.dataset.path!,
         content,
         start: position,
         end: position + content.length,
+        ...(file.dataset.mime ? { mime: file.dataset.mime } : {}),
+        ...(file.dataset.filename ? { filename: file.dataset.filename } : {}),
+        ...(file.dataset.url ? { url: file.dataset.url } : {}),
+        ...(source ? { source } : {}),
       })
       position += content.length
     }
@@ -1288,6 +1401,9 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
         }
         if (store.popover === "slash") {
           slashOnKeyDown(event)
+          if (event.key === "ArrowUp" || event.key === "ArrowDown" || ctrlNav) {
+            scrollSlashActiveIntoView()
+          }
         }
         event.preventDefault()
         return
@@ -1369,6 +1485,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
     model: props.controls.model.selection,
     providerID: props.controls.model.selection.current()?.provider?.id,
     modelName: props.controls.model.selection.current()?.name ?? language.t("dialog.model.select.title"),
+    newLayoutDesigns: props.controls.newLayoutDesigns,
     style: control(),
     onClose: restoreFocus,
     onUnpaidClick: () => {
@@ -1379,6 +1496,11 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
   }))
 
   const newSession = () => props.variant === "new-session"
+  const bindEditorRef = (el: HTMLDivElement) => {
+    editorRef = el
+    restoreEndOnFocus = true
+    props.ref?.(el)
+  }
   const showAgentControl = createMemo(() => props.controls.agents.visible && props.controls.agents.options.length > 0)
   const agentControlState = createMemo<ComposerAgentControlState>(() => ({
     title: language.t("command.agent.cycle"),
@@ -1407,6 +1529,8 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
         setSlashActive={setSlashActive}
         onSlashSelect={handleSlashSelect}
         commandKeybind={command.keybind}
+        commandKeybindParts={command.keybindParts}
+        newLayoutDesigns={props.controls.newLayoutDesigns}
         t={(key) => language.t(key as Parameters<typeof language.t>[0])}
       />
       <Switch>
@@ -1460,10 +1584,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
                 <div class="relative max-h-[180px] overflow-y-auto no-scrollbar" ref={(el) => (scrollRef = el)}>
                   <div
                     data-component="prompt-input"
-                    ref={(el) => {
-                      editorRef = el
-                      props.ref?.(el)
-                    }}
+                    ref={bindEditorRef}
                     role="textbox"
                     aria-multiline="true"
                     aria-label={designPlaceholder()}
@@ -1478,6 +1599,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
                     onPaste={handlePaste}
                     onCompositionStart={handleCompositionStart}
                     onCompositionEnd={handleCompositionEnd}
+                    onFocus={handleFocus}
                     onBlur={handleBlur}
                     onKeyDown={handleKeyDown}
                     classList={{
@@ -1498,7 +1620,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
                 </div>
               </div>
               <div class="flex h-11 items-center px-2">
-                <div class="flex min-w-0 flex-1 items-center gap-0">
+                <div class="flex min-w-0 flex-1 items-center gap-1">
                   {fileAttachmentInput()}
                   <TooltipV2
                     placement="top"
@@ -1530,6 +1652,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
                   <Show when={!providersLoading() && store.mode !== "shell" && showVariantControl()}>
                     <div
                       data-component="prompt-variant-control"
+                      class="[&_[data-action=prompt-model-variant]]:![font-weight:440]"
                       classList={{
                         "animate-in fade-in": providersShouldFadeIn(),
                         "hidden group-hover/prompt-input:block group-focus-within/prompt-input:block":
@@ -1546,22 +1669,45 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
                           </>
                         }
                       >
-                        <Select
-                          size="normal"
-                          options={variants()}
-                          current={props.controls.model.selection.variant.current() ?? "default"}
-                          label={(x) => (x === "default" ? language.t("common.default") : x)}
+                        <MenuV2
+                          gutter={6}
+                          modal={false}
+                          placement="top-start"
                           onOpenChange={(open) => setStore("variantOpen", open)}
-                          onSelect={(value) => {
-                            props.controls.model.selection.variant.set(value === "default" ? undefined : value)
-                            restoreFocus()
-                          }}
-                          class="capitalize max-w-[160px] justify-start text-v2-text-text-faint"
-                          valueClass="truncate text-[13px] font-[440] leading-5 text-v2-text-text-faint"
-                          triggerStyle={control()}
-                          triggerProps={{ "data-action": "prompt-model-variant" }}
-                          variant="ghost"
-                        />
+                        >
+                          <MenuV2.Trigger
+                            as={ButtonV2}
+                            data-action="prompt-model-variant"
+                            variant="ghost-muted"
+                            size="normal"
+                            class="max-w-[160px] justify-start capitalize"
+                            style={control()}
+                          >
+                            <span class="truncate">
+                              {props.controls.model.selection.variant.current() ?? language.t("common.default")}
+                            </span>
+                            <span class="-ml-0.5 -mr-1 flex shrink-0">
+                              <Icon name="chevron-down" size="small" />
+                            </span>
+                          </MenuV2.Trigger>
+                          <MenuV2.Portal>
+                            <MenuV2.Content>
+                              <MenuV2.RadioGroup
+                                value={props.controls.model.selection.variant.current() ?? "default"}
+                                onChange={(value) => {
+                                  props.controls.model.selection.variant.set(value === "default" ? undefined : value)
+                                  restoreFocus()
+                                }}
+                              >
+                                {variants().map((value) => (
+                                  <MenuV2.RadioItem value={value} class="capitalize">
+                                    {value === "default" ? language.t("common.default") : value}
+                                  </MenuV2.RadioItem>
+                                ))}
+                              </MenuV2.RadioGroup>
+                            </MenuV2.Content>
+                          </MenuV2.Portal>
+                        </MenuV2>
                       </TooltipV2>
                     </div>
                   </Show>
@@ -1641,10 +1787,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
               >
                 <div
                   data-component="prompt-input"
-                  ref={(el) => {
-                    editorRef = el
-                    props.ref?.(el)
-                  }}
+                  ref={bindEditorRef}
                   role="textbox"
                   aria-multiline="true"
                   aria-label={placeholder()}
@@ -1659,6 +1802,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
                   onPaste={handlePaste}
                   onCompositionStart={handleCompositionStart}
                   onCompositionEnd={handleCompositionEnd}
+                  onFocus={handleFocus}
                   onBlur={handleBlur}
                   onKeyDown={handleKeyDown}
                   classList={{
@@ -1943,6 +2087,7 @@ type ComposerModelControlState = {
   model: ReturnType<typeof useLocal>["model"]
   providerID?: string
   modelName: string
+  newLayoutDesigns: boolean
   style: JSX.CSSProperties | undefined
   onClose: () => void
   onUnpaidClick: () => void
@@ -2033,36 +2178,65 @@ function ComposerModelControl(props: { state: ComposerModelControlState }) {
             </>
           }
         >
-          <ModelSelectorPopover
-            model={props.state.model}
-            triggerAs={Button}
-            triggerProps={{
-              variant: "ghost",
-              size: "normal",
-              style: props.state.style,
-              class:
-                "min-w-0 max-w-[220px] justify-start text-[13px] font-[440] leading-5 text-v2-text-text-faint group",
-              classList: { "animate-in fade-in": props.state.shouldAnimate },
-              "data-action": "prompt-model",
-            }}
-            onClose={props.state.onClose}
+          <Show
+            when={props.state.newLayoutDesigns}
+            fallback={
+              <ModelSelectorPopover
+                model={props.state.model}
+                triggerAs={Button}
+                triggerProps={{
+                  variant: "ghost",
+                  size: "normal",
+                  style: props.state.style,
+                  class:
+                    "min-w-0 max-w-[220px] justify-start text-[13px] font-[440] leading-5 text-v2-text-text-faint group",
+                  classList: { "animate-in fade-in": props.state.shouldAnimate },
+                  "data-action": "prompt-model",
+                }}
+                onClose={props.state.onClose}
+              >
+                <ModelControlContent state={props.state} />
+              </ModelSelectorPopover>
+            }
           >
-            <Show when={props.state.providerID}>
-              {(providerID) => (
-                <ProviderIcon
-                  id={providerID()}
-                  class="size-4 shrink-0 opacity-40 group-hover:opacity-100 transition-opacity duration-150"
-                  style={{ "will-change": "opacity", transform: "translateZ(0)" }}
-                />
-              )}
-            </Show>
-            <span class="truncate">{props.state.modelName}</span>
-            <span class="-ml-1 shrink-0 flex size-fit">
-              <Icon name="chevron-down" size="small" class="text-v2-icon-icon-muted" />
-            </span>
-          </ModelSelectorPopover>
+            <ModelSelectorPopoverV2
+              model={props.state.model}
+              triggerAs={ButtonV2}
+              triggerProps={{
+                variant: "ghost-muted",
+                size: "normal",
+                style: props.state.style,
+                class: "min-w-0 max-w-[220px] justify-start ![font-weight:440] group",
+                classList: { "animate-in fade-in": props.state.shouldAnimate },
+                "data-action": "prompt-model",
+              }}
+              onClose={props.state.onClose}
+            >
+              <ModelControlContent state={props.state} v2 />
+            </ModelSelectorPopoverV2>
+          </Show>
         </TooltipV2>
       </Show>
     </Show>
   )
 }
+
+function ModelControlContent(props: { state: ComposerModelControlState; v2?: boolean }) {
+  return (
+    <>
+      <Show when={props.state.providerID}>
+        {(providerID) => (
+          <ProviderIcon
+            id={providerID()}
+            class="size-4 shrink-0 opacity-40 group-hover:opacity-100 transition-opacity duration-150"
+            style={{ "will-change": "opacity", transform: "translateZ(0)" }}
+          />
+        )}
+      </Show>
+      <span class="truncate">{props.state.modelName}</span>
+      <span class={props.v2 ? "-ml-0.5 -mr-1 flex shrink-0" : "-ml-1 shrink-0 flex size-fit"}>
+        <Icon name="chevron-down" size="small" class="text-v2-icon-icon-muted" />
+      </span>
+    </>
+  )
+}

packages/app/src/components/prompt-input/build-request-parts.test.ts

@@ -100,6 +100,41 @@ describe("buildRequestParts", () => {
     )
   })
 
+  test("preserves reference aliases as directory file parts", () => {
+    const result = buildRequestParts({
+      prompt: [
+        {
+          type: "file",
+          path: "/repo/../docs",
+          content: "@docs",
+          start: 0,
+          end: 5,
+          mime: "application/x-directory",
+          filename: "docs",
+        },
+      ],
+      context: [],
+      images: [],
+      text: "@docs",
+      messageID: "msg_reference",
+      sessionID: "ses_reference",
+      sessionDirectory: "/repo/app",
+    })
+
+    const filePart = result.requestParts.find((part) => part.type === "file")
+    expect(filePart).toBeDefined()
+    if (filePart?.type === "file") {
+      expect(filePart.mime).toBe("application/x-directory")
+      expect(filePart.filename).toBe("docs")
+      expect(filePart.url).toBe("file:///repo/../docs")
+      expect(filePart.source?.type).toBe("file")
+      if (filePart.source?.type === "file") {
+        expect(filePart.source.path).toBe("/repo/../docs")
+        expect(filePart.source.text.value).toBe("@docs")
+      }
+    }
+  })
+
   test("deduplicates context files when prompt already includes same path", () => {
     const prompt: Prompt = [{ type: "file", path: "src/foo.ts", content: "@src/foo.ts", start: 0, end: 11 }]
 

packages/app/src/components/prompt-input/build-request-parts.ts

@@ -99,21 +99,31 @@ export function buildRequestParts(input: BuildRequestPartsInput) {
 
   const files = input.prompt.filter(isFileAttachment).map((attachment) => {
     const path = absolute(input.sessionDirectory, attachment.path)
+    const source = attachment.source
+      ? {
+          ...attachment.source,
+          text: {
+            value: attachment.content,
+            start: attachment.start,
+            end: attachment.end,
+          },
+        }
+      : {
+          type: "file" as const,
+          text: {
+            value: attachment.content,
+            start: attachment.start,
+            end: attachment.end,
+          },
+          path,
+        }
     return {
       id: Identifier.ascending("part"),
       type: "file",
-      mime: "text/plain",
-      url: `file://${encodeFilePath(path)}${fileQuery(attachment.selection)}`,
-      filename: getFilename(attachment.path),
-      source: {
-        type: "file",
-        text: {
-          value: attachment.content,
-          start: attachment.start,
-          end: attachment.end,
-        },
-        path,
-      },
+      mime: attachment.mime ?? "text/plain",
+      url: attachment.url ?? `file://${encodeFilePath(path)}${fileQuery(attachment.selection)}`,
+      filename: attachment.filename ?? getFilename(attachment.path),
+      source,
     } satisfies PromptRequestPart
   })
 

packages/app/src/components/prompt-input/context-items.tsx

@@ -1,7 +1,7 @@
 import { Component, For, Show } from "solid-js"
 import { FileIcon } from "@opencode-ai/ui/file-icon"
 import { IconButton } from "@opencode-ai/ui/icon-button"
-import { Tooltip } from "@opencode-ai/ui/tooltip"
+import { TooltipV2 } from "@opencode-ai/ui/v2/tooltip-v2"
 import { getDirectory, getFilename, getFilenameTruncated } from "@opencode-ai/core/util/path"
 import type { ContextItem } from "@/context/prompt"
 
@@ -27,7 +27,7 @@ export const PromptContextItems: Component<ContextItemsProps> = (props) => {
             const selected = props.active(item)
 
             return (
-              <Tooltip
+              <TooltipV2
                 value={
                   <span class="flex max-w-[300px]">
                     <span class="text-text-invert-base truncate-start [unicode-bidi:plaintext] min-w-0">
@@ -37,7 +37,7 @@ export const PromptContextItems: Component<ContextItemsProps> = (props) => {
                   </span>
                 }
                 placement="top"
-                openDelay={2000}
+                openDelay={800}
               >
                 <div
                   classList={{
@@ -78,7 +78,7 @@ export const PromptContextItems: Component<ContextItemsProps> = (props) => {
                     {(comment) => <div class="text-12-regular text-text-strong ml-5 pr-1 truncate">{comment()}</div>}
                   </Show>
                 </div>
-              </Tooltip>
+              </TooltipV2>
             )
           }}
         </For>

packages/app/src/components/prompt-input/slash-popover.tsx

@@ -1,10 +1,22 @@
 import { Component, For, Match, Show, Switch } from "solid-js"
 import { FileIcon } from "@opencode-ai/ui/file-icon"
 import { Icon } from "@opencode-ai/ui/icon"
+import { Tag } from "@opencode-ai/ui/v2/badge-v2"
+import { KeybindV2 } from "@opencode-ai/ui/v2/keybind-v2"
 import { getDirectory, getFilename } from "@opencode-ai/core/util/path"
 
 export type AtOption =
   | { type: "agent"; name: string; display: string }
+  | {
+      type: "resource"
+      name: string
+      uri: string
+      client: string
+      display: string
+      description?: string
+      mime?: string
+    }
+  | { type: "reference"; name: string; path: string; display: string; description: string }
   | { type: "file"; path: string; display: string; recent?: boolean }
 
 export interface SlashCommand {
@@ -30,6 +42,8 @@ type PromptPopoverProps = {
   setSlashActive: (id: string) => void
   onSlashSelect: (item: SlashCommand) => void
   commandKeybind: (id: string) => string | undefined
+  commandKeybindParts: (id: string) => string[]
+  newLayoutDesigns: boolean
   t: (key: string) => string
 }
 
@@ -41,15 +55,29 @@ export const PromptPopover: Component<PromptPopoverProps> = (props) => {
           if (props.popover === "slash") props.setSlashPopoverRef(el)
         }}
         class="absolute inset-x-0 -top-2 -translate-y-full origin-bottom-left max-h-80 min-h-10
-                 overflow-auto no-scrollbar flex flex-col p-2 rounded-[12px]
-                 bg-surface-raised-stronger-non-alpha shadow-[var(--shadow-lg-border-base)]"
+                 overflow-auto no-scrollbar flex flex-col p-2"
+        classList={{
+          "z-[70] rounded-[10px] bg-v2-background-bg-base shadow-[var(--v2-elevation-raised)]": props.newLayoutDesigns,
+          "rounded-[12px] bg-surface-raised-stronger-non-alpha shadow-[var(--shadow-lg-border-base)]":
+            !props.newLayoutDesigns,
+        }}
         onMouseDown={(e) => e.preventDefault()}
       >
         <Switch>
           <Match when={props.popover === "at"}>
             <Show
               when={props.atFlat.length > 0}
-              fallback={<div class="text-text-weak px-2 py-1">{props.t("prompt.popover.emptyResults")}</div>}
+              fallback={
+                <div
+                  class="px-2 py-1"
+                  classList={{
+                    "text-v2-text-text-muted": props.newLayoutDesigns,
+                    "text-text-weak": !props.newLayoutDesigns,
+                  }}
+                >
+                  {props.t("prompt.popover.emptyResults")}
+                </div>
+              }
             >
               <For each={props.atFlat.slice(0, 10)}>
                 {(item) => {
@@ -58,13 +86,117 @@ export const PromptPopover: Component<PromptPopoverProps> = (props) => {
                   if (item.type === "agent") {
                     return (
                       <button
-                        class="w-full flex items-center gap-x-2 rounded-md px-2 py-0.5"
-                        classList={{ "bg-surface-raised-base-hover": props.atActive === key }}
+                        class="w-full flex items-center gap-x-2 px-2 py-0.5"
+                        classList={{
+                          "rounded-[4px]": props.newLayoutDesigns,
+                          "rounded-md": !props.newLayoutDesigns,
+                          "bg-v2-overlay-simple-overlay-hover": props.newLayoutDesigns && props.atActive === key,
+                          "bg-surface-raised-base-hover": !props.newLayoutDesigns && props.atActive === key,
+                        }}
                         onClick={() => props.onAtSelect(item)}
-                        onMouseEnter={() => props.setAtActive(key)}
+                        onPointerMove={() => props.setAtActive(key)}
                       >
                         <Icon name="brain" size="small" class="text-icon-info-active shrink-0" />
-                        <span class="text-14-regular text-text-strong whitespace-nowrap">@{item.name}</span>
+                        <span
+                          class="whitespace-nowrap"
+                          classList={{
+                            "text-[13px] leading-[calc(var(--font-size-base)*1.8)] tracking-[-0.04px] [font-weight:440]":
+                              props.newLayoutDesigns,
+                            "text-v2-text-text-base": props.newLayoutDesigns,
+                            "text-14-regular": !props.newLayoutDesigns,
+                            "text-text-strong": !props.newLayoutDesigns,
+                          }}
+                        >
+                          @{item.name}
+                        </span>
+                      </button>
+                    )
+                  }
+
+                  if (item.type === "resource") {
+                    return (
+                      <button
+                        class="w-full flex items-center gap-x-2 px-2 py-0.5"
+                        classList={{
+                          "rounded-[4px]": props.newLayoutDesigns,
+                          "rounded-md": !props.newLayoutDesigns,
+                          "bg-v2-overlay-simple-overlay-hover": props.newLayoutDesigns && props.atActive === key,
+                          "bg-surface-raised-base-hover": !props.newLayoutDesigns && props.atActive === key,
+                        }}
+                        onClick={() => props.onAtSelect(item)}
+                        onPointerMove={() => props.setAtActive(key)}
+                      >
+                        <FileIcon node={{ path: item.uri, type: "file" }} class="shrink-0 size-4" />
+                        <div
+                          class="flex items-center min-w-0"
+                          classList={{
+                            "text-[13px] leading-[calc(var(--font-size-base)*1.8)] tracking-[-0.04px] [font-weight:440]":
+                              props.newLayoutDesigns,
+                            "text-14-regular": !props.newLayoutDesigns,
+                          }}
+                        >
+                          <span
+                            class="text-text-strong whitespace-nowrap"
+                            classList={{ "text-v2-text-text-base": props.newLayoutDesigns }}
+                          >
+                            @{item.name}
+                          </span>
+                          <Show when={item.description}>
+                            {(description) => (
+                              <span
+                                class="whitespace-nowrap truncate min-w-0 ml-2"
+                                classList={{
+                                  "text-v2-text-text-muted": props.newLayoutDesigns,
+                                  "text-text-weak": !props.newLayoutDesigns,
+                                }}
+                              >
+                                {description()}
+                              </span>
+                            )}
+                          </Show>
+                        </div>
+                      </button>
+                    )
+                  }
+
+                  if (item.type === "reference") {
+                    return (
+                      <button
+                        class="w-full flex items-center gap-x-2 px-2 py-0.5"
+                        classList={{
+                          "rounded-[4px]": props.newLayoutDesigns,
+                          "rounded-md": !props.newLayoutDesigns,
+                          "bg-v2-overlay-simple-overlay-hover": props.newLayoutDesigns && props.atActive === key,
+                          "bg-surface-raised-base-hover": !props.newLayoutDesigns && props.atActive === key,
+                        }}
+                        onClick={() => props.onAtSelect(item)}
+                        onPointerMove={() => props.setAtActive(key)}
+                      >
+                        <FileIcon node={{ path: item.path, type: "directory" }} class="shrink-0 size-4" />
+                        <div
+                          class="flex items-center min-w-0"
+                          classList={{
+                            "text-[13px] leading-[calc(var(--font-size-base)*1.8)] tracking-[-0.04px] [font-weight:440]":
+                              props.newLayoutDesigns,
+                            "text-14-regular": !props.newLayoutDesigns,
+                          }}
+                        >
+                          <span
+                            class="text-text-strong whitespace-nowrap"
+                            classList={{ "text-v2-text-text-base": props.newLayoutDesigns }}
+                          >
+                            @{item.name}
+                          </span>
+                          <span
+                            class="whitespace-nowrap truncate min-w-0 ml-2"
+                            classList={{
+                              "text-v2-text-text-muted": props.newLayoutDesigns,
+                              "text-text-weak": !props.newLayoutDesigns,
+                            }}
+                          >
+                            {item.description}
+                          </span>
+                        </div>
                       </button>
                     )
                   }
@@ -75,16 +207,44 @@ export const PromptPopover: Component<PromptPopoverProps> = (props) => {
 
                   return (
                     <button
-                      class="w-full flex items-center gap-x-2 rounded-md px-2 py-0.5"
-                      classList={{ "bg-surface-raised-base-hover": props.atActive === key }}
+                      class="w-full flex items-center gap-x-2 px-2 py-0.5"
+                      classList={{
+                        "rounded-[4px]": props.newLayoutDesigns,
+                        "rounded-md": !props.newLayoutDesigns,
+                        "bg-v2-overlay-simple-overlay-hover": props.newLayoutDesigns && props.atActive === key,
+                        "bg-surface-raised-base-hover": !props.newLayoutDesigns && props.atActive === key,
+                      }}
                       onClick={() => props.onAtSelect(item)}
-                      onMouseEnter={() => props.setAtActive(key)}
+                      onPointerMove={() => props.setAtActive(key)}
                     >
                       <FileIcon node={{ path: item.path, type: "file" }} class="shrink-0 size-4" />
-                      <div class="flex items-center text-14-regular min-w-0">
-                        <span class="text-text-weak whitespace-nowrap truncate min-w-0">{directory}</span>
+                      <div
+                        class="flex items-center min-w-0"
+                        classList={{
+                          "text-[13px] leading-[calc(var(--font-size-base)*1.8)] tracking-[-0.04px] [font-weight:440]":
+                            props.newLayoutDesigns,
+                          "text-14-regular": !props.newLayoutDesigns,
+                        }}
+                      >
+                        <span
+                          class="whitespace-nowrap truncate min-w-0"
+                          classList={{
+                            "text-v2-text-text-muted": props.newLayoutDesigns,
+                            "text-text-weak": !props.newLayoutDesigns,
+                          }}
+                        >
+                          {directory}
+                        </span>
                         <Show when={!isDirectory}>
-                          <span class="text-text-strong whitespace-nowrap">{filename}</span>
+                          <span
+                            class="whitespace-nowrap"
+                            classList={{
+                              "text-v2-text-text-base": props.newLayoutDesigns,
+                              "text-text-strong": !props.newLayoutDesigns,
+                            }}
+                          >
+                            {filename}
+                          </span>
                         </Show>
                       </div>
                     </button>
@@ -96,41 +256,98 @@ export const PromptPopover: Component<PromptPopoverProps> = (props) => {
           <Match when={props.popover === "slash"}>
             <Show
               when={props.slashFlat.length > 0}
-              fallback={<div class="text-text-weak px-2 py-1">{props.t("prompt.popover.emptyCommands")}</div>}
+              fallback={
+                <div
+                  class="px-2 py-1"
+                  classList={{
+                    "text-v2-text-text-muted": props.newLayoutDesigns,
+                    "text-text-weak": !props.newLayoutDesigns,
+                  }}
+                >
+                  {props.t("prompt.popover.emptyCommands")}
+                </div>
+              }
             >
               <For each={props.slashFlat}>
-                {(cmd) => (
-                  <button
-                    data-slash-id={cmd.id}
-                    classList={{
-                      "w-full flex items-center justify-between gap-4 rounded-md px-2 py-1": true,
-                      "bg-surface-raised-base-hover": props.slashActive === cmd.id,
-                    }}
-                    onClick={() => props.onSlashSelect(cmd)}
-                    onMouseEnter={() => props.setSlashActive(cmd.id)}
-                  >
-                    <div class="flex items-center gap-2 min-w-0">
-                      <span class="text-14-regular text-text-strong whitespace-nowrap">/{cmd.trigger}</span>
-                      <Show when={cmd.description}>
-                        <span class="text-14-regular text-text-weak truncate">{cmd.description}</span>
-                      </Show>
-                    </div>
-                    <div class="flex items-center gap-2 shrink-0">
-                      <Show when={cmd.type === "custom" && cmd.source !== "command"}>
-                        <span class="text-11-regular text-text-subtle px-1.5 py-0.5 bg-surface-base rounded">
-                          {cmd.source === "skill"
-                            ? props.t("prompt.slash.badge.skill")
-                            : cmd.source === "mcp"
-                              ? props.t("prompt.slash.badge.mcp")
-                              : props.t("prompt.slash.badge.custom")}
+                {(cmd) => {
+                  const keybind = () => props.commandKeybind(cmd.id)
+                  const keybindParts = () => props.commandKeybindParts(cmd.id)
+                  return (
+                    <button
+                      data-slash-id={cmd.id}
+                      classList={{
+                        "w-full flex items-center justify-between gap-4 px-2 py-1": true,
+                        "rounded-[4px] scroll-my-2": props.newLayoutDesigns,
+                        "rounded-md": !props.newLayoutDesigns,
+                        "bg-v2-overlay-simple-overlay-hover": props.newLayoutDesigns && props.slashActive === cmd.id,
+                        "bg-surface-raised-base-hover": !props.newLayoutDesigns && props.slashActive === cmd.id,
+                      }}
+                      onClick={() => props.onSlashSelect(cmd)}
+                      onPointerMove={() => props.setSlashActive(cmd.id)}
+                    >
+                      <div class="flex items-center gap-2 min-w-0">
+                        <span
+                          class="whitespace-nowrap"
+                          classList={{
+                            "text-[13px] leading-[calc(var(--font-size-base)*1.8)] tracking-[-0.04px] [font-weight:440]":
+                              props.newLayoutDesigns,
+                            "text-v2-text-text-base": props.newLayoutDesigns,
+                            "text-14-regular": !props.newLayoutDesigns,
+                            "text-text-strong": !props.newLayoutDesigns,
+                          }}
+                        >
+                          /{cmd.trigger}
                         </span>
-                      </Show>
-                      <Show when={props.commandKeybind(cmd.id)}>
-                        <span class="text-12-regular text-text-subtle">{props.commandKeybind(cmd.id)}</span>
-                      </Show>
-                    </div>
-                  </button>
-                )}
+                        <Show when={cmd.description}>
+                          <span
+                            class="truncate"
+                            classList={{
+                              "text-[13px] leading-[calc(var(--font-size-base)*1.8)] tracking-[-0.04px] [font-weight:440]":
+                                props.newLayoutDesigns,
+                              "text-v2-text-text-muted": props.newLayoutDesigns,
+                              "text-14-regular": !props.newLayoutDesigns,
+                              "text-text-weak": !props.newLayoutDesigns,
+                            }}
+                          >
+                            {cmd.description}
+                          </span>
+                        </Show>
+                      </div>
+                      <div class="flex items-center gap-2 shrink-0">
+                        <Show when={cmd.type === "custom" && cmd.source !== "command"}>
+                          <Show
+                            when={props.newLayoutDesigns}
+                            fallback={
+                              <span class="text-11-regular px-1.5 py-0.5 rounded bg-surface-base text-text-subtle">
+                                {cmd.source === "skill"
+                                  ? props.t("prompt.slash.badge.skill")
+                                  : cmd.source === "mcp"
+                                    ? props.t("prompt.slash.badge.mcp")
+                                    : props.t("prompt.slash.badge.custom")}
+                              </span>
+                            }
+                          >
+                            <Tag>
+                              {cmd.source === "skill"
+                                ? props.t("prompt.slash.badge.skill")
+                                : cmd.source === "mcp"
+                                  ? props.t("prompt.slash.badge.mcp")
+                                  : props.t("prompt.slash.badge.custom")}
+                            </Tag>
+                          </Show>
+                        </Show>
+                        <Show when={props.newLayoutDesigns ? keybindParts().length > 0 : keybind()}>
+                          <Show
+                            when={props.newLayoutDesigns}
+                            fallback={<span class="text-12-regular text-text-subtle">{keybind()}</span>}
+                          >
+                            <KeybindV2 keys={keybindParts()} variant="neutral" />
+                          </Show>
+                        </Show>
+                      </div>
+                    </button>
+                  )
+                }}
               </For>
             </Show>
           </Match>

packages/app/src/components/prompt-input/submission-state.ts

@@ -7,6 +7,7 @@ export function createPromptSubmissionState(input: {
   prompt: Prompt
   context: (ContextItem & { key: string })[]
 }) {
+  const initial = input.target
   let target = input.target
   let cleared: Prompt | undefined
 
@@ -15,6 +16,7 @@ export function createPromptSubmissionState(input: {
     context: input.context,
     target: () => target,
     clear() {
+      if (initial !== target) initial.reset()
       target.reset()
       cleared = target.current()
     },

packages/app/src/components/prompt-project-selector.tsx

@@ -1,4 +1,4 @@
-import { For, Show, splitProps, type Accessor, type ComponentProps } from "solid-js"
+import { createEffect, For, onCleanup, Show, splitProps, type Accessor, type ComponentProps } from "solid-js"
 import { createStore } from "solid-js/store"
 import { DropdownMenu } from "@opencode-ai/ui/dropdown-menu"
 import { Icon } from "@opencode-ai/ui/icon"
@@ -8,6 +8,7 @@ import { getProjectAvatarVariant } from "@/context/layout"
 import { useLanguage } from "@/context/language"
 import { displayName, getProjectAvatarSource } from "@/pages/layout/helpers"
 import { pathKey } from "@/utils/path-key"
+import { handleDocumentSearchKeydown } from "@/utils/search-keydown"
 
 export type PromptProject = {
   name?: string
@@ -101,6 +102,16 @@ export function createPromptProjectController(input: {
     setStore({ open: false, search: "", active: "" })
     input.controls().add(language.t("command.project.open"), server)
   }
+  const setSearch = (value: string) => {
+    const search = value.trim().toLowerCase()
+    const first = input
+      .controls()
+      .available.find((project) => !search || displayName(project).toLowerCase().includes(search))
+    setStore({
+      search: value,
+      active: first ? projectKey(first) : actionKey(servers().length > 1 ? undefined : servers()[0]?.key),
+    })
+  }
 
   return {
     selected,
@@ -127,16 +138,7 @@ export function createPromptProjectController(input: {
       }
       setStore({ open: false, search: "", active: "" })
     },
-    setSearch(value: string) {
-      const search = value.trim().toLowerCase()
-      const first = input
-        .controls()
-        .available.find((project) => !search || displayName(project).toLowerCase().includes(search))
-      setStore({
-        search: value,
-        active: first ? projectKey(first) : actionKey(servers().length > 1 ? undefined : servers()[0]?.key),
-      })
-    },
+    setSearch,
     clearSearch() {
       setStore({ search: "", active: initialActive() })
       setTimeout(() => searchRef?.focus())
@@ -170,6 +172,9 @@ export function createPromptProjectController(input: {
     focusSearch() {
       setTimeout(() => requestAnimationFrame(() => searchRef?.focus()))
     },
+    handleSearchKeydown(event: KeyboardEvent) {
+      return handleDocumentSearchKeydown(searchRef, event, store.search, setSearch)
+    },
   }
 }
 
@@ -243,6 +248,13 @@ export function PromptProjectSelector(props: {
     return project ? props.controller.projectKey(project) : undefined
   }
 
+  createEffect(() => {
+    if (!props.controller.open()) return
+    const handler = (event: KeyboardEvent) => props.controller.handleSearchKeydown(event)
+    document.addEventListener("keydown", handler, true)
+    onCleanup(() => document.removeEventListener("keydown", handler, true))
+  })
+
   return (
     <DropdownMenu
       open={props.controller.open()}

packages/app/src/components/prompt-workspace-selector.tsx

@@ -92,11 +92,17 @@ export function PromptWorkspaceSelector(props: {
           </MenuV2.Content>
         </MenuV2.Portal>
       </MenuV2>
-      <span class="hidden select-none opacity-50 sm:inline mx-1">/</span>
-      <div class="flex h-7 min-w-0 max-w-[220px] items-center gap-1.5 px-2 text-[13px] font-[440] leading-5 tracking-[-0.04px]">
-        <Icon name="branch" size="small" class="shrink-0 text-v2-icon-icon-muted" />
-        <span class="min-w-0 truncate">{props.branch || "main"}</span>
-      </div>
+      <Show when={props.branch}>
+        {(branch) => (
+          <>
+            <span class="hidden select-none opacity-50 sm:inline mx-1">/</span>
+            <div class="flex h-7 min-w-0 max-w-[220px] items-center gap-1.5 px-2 text-[13px] font-[440] leading-5 tracking-[-0.04px]">
+              <Icon name="branch" size="small" class="shrink-0 text-v2-icon-icon-muted" />
+              <span class="min-w-0 truncate">{branch()}</span>
+            </div>
+          </>
+        )}
+      </Show>
     </>
   )
 }

packages/app/src/components/session-context-usage.tsx

@@ -1,7 +1,9 @@
-import { Match, Show, Switch, createMemo } from "solid-js"
-import { Tooltip, type TooltipProps } from "@opencode-ai/ui/tooltip"
+import { Match, Show, Switch, createMemo, type ComponentProps, type JSX } from "solid-js"
 import { ProgressCircle } from "@opencode-ai/ui/progress-circle"
+import { ProgressCircleV2 } from "@opencode-ai/ui/v2/progress-circle-v2"
 import { Button } from "@opencode-ai/ui/button"
+import { IconButtonV2 } from "@opencode-ai/ui/v2/icon-button-v2"
+import { TooltipV2 } from "@opencode-ai/ui/v2/tooltip-v2"
 
 import { useFile } from "@/context/file"
 import { useLayout } from "@/context/layout"
@@ -15,7 +17,17 @@ import { createSessionTabs } from "@/pages/session/helpers"
 
 interface SessionContextUsageProps {
   variant?: "button" | "indicator"
-  placement?: TooltipProps["placement"]
+  buttonAppearance?: "default" | "v2"
+  placement?: ComponentProps<typeof TooltipV2>["placement"]
+}
+
+function ContextTooltipRow(props: { name: JSX.Element; value: JSX.Element }) {
+  return (
+    <div class="flex min-w-0 items-center gap-4">
+      <span class="shrink-0 text-v2-text-text-muted">{props.name}</span>
+      <span class="ml-auto min-w-0 truncate text-right text-v2-text-text-base">{props.value}</span>
+    </div>
+  )
 }
 
 function openSessionContext(args: {
@@ -23,7 +35,7 @@ function openSessionContext(args: {
   layout: ReturnType<typeof useLayout>
   tabs: ReturnType<ReturnType<typeof useLayout>["tabs"]>
 }) {
-  if (!args.view.reviewPanel.opened()) args.view.reviewPanel.open()
+  args.view.reviewPanel.open(args.view.reviewPanel.opened() ? "other" : "context-button")
   if (args.layout.fileTree.opened() && args.layout.fileTree.tab() !== "all") args.layout.fileTree.setTab("all")
   void args.tabs.open("context")
   args.tabs.setActive("context")
@@ -39,6 +51,7 @@ export function SessionContextUsage(props: SessionContextUsageProps) {
   const { params, tabs, view } = useSessionLayout()
 
   const variant = createMemo(() => props.variant ?? "button")
+  const buttonAppearance = createMemo(() => props.buttonAppearance ?? "default")
   const tabState = createSessionTabs({
     tabs,
     pathFromTab: file.pathFromTab,
@@ -60,16 +73,25 @@ export function SessionContextUsage(props: SessionContextUsageProps) {
   const cost = createMemo(() => {
     return usd().format(info()?.cost ?? 0)
   })
+  const contextVisible = createMemo(() => view().reviewPanel.opened() && tabState.activeTab() === "context")
+  const hasOtherTabs = createMemo(() =>
+    tabs()
+      .all()
+      .some((tab) => tab !== "context" && tab !== "review"),
+  )
 
   const openContext = () => {
     if (!params.id) return
 
-    if (tabState.activeTab() === "context") {
+    const sessionView = view()
+    if (contextVisible()) {
       tabs().close("context")
+      if (sessionView.reviewPanel.source() === "context-button" && !hasOtherTabs()) sessionView.reviewPanel.close()
       return
     }
+
     openSessionContext({
-      view: view(),
+      view: sessionView,
       layout,
       tabs: tabs(),
     })
@@ -77,42 +99,54 @@ export function SessionContextUsage(props: SessionContextUsageProps) {
 
   const circle = () => (
     <div class="flex items-center justify-center">
-      <ProgressCircle size={16} strokeWidth={2} percentage={context()?.usage ?? 0} />
+      <ProgressCircle
+        size={16}
+        strokeWidth={2}
+        percentage={context()?.usage ?? 0}
+        style={
+          variant() === "indicator"
+            ? {
+                "--progress-circle-background": "var(--v2-background-bg-layer-04, var(--border-weak-base))",
+                "--progress-circle-background-overlay": "var(--v2-overlay-simple-overlay-pressed, transparent)",
+                "--progress-circle-progress": "var(--v2-icon-icon-base, var(--icon-base))",
+              }
+            : undefined
+        }
+      />
+    </div>
+  )
+  const circleV2 = () => (
+    <div class="flex items-center justify-center">
+      <ProgressCircleV2 percentage={context()?.usage ?? 0} />
     </div>
   )
 
   const tooltipValue = () => (
-    <div>
-      <Show when={tokens()}>
-        {(value) => (
-          <div class="flex items-center gap-2">
-            <span class="text-text-invert-strong">
-              {getSessionTokenTotal(value())?.toLocaleString(language.intl())}
-            </span>
-            <span class="text-text-invert-base">{language.t("context.usage.tokens")}</span>
-          </div>
-        )}
-      </Show>
-      <Show when={context()}>
-        {(ctx) => (
-          <div class="flex items-center gap-2">
-            <span class="text-text-invert-strong">{ctx().usage ?? 0}%</span>
-            <span class="text-text-invert-base">{language.t("context.usage.usage")}</span>
-          </div>
-        )}
-      </Show>
-      <div class="flex items-center gap-2">
-        <span class="text-text-invert-strong">{cost()}</span>
-        <span class="text-text-invert-base">{language.t("context.usage.cost")}</span>
-      </div>
+    <div class="flex w-[120px] flex-col gap-2">
+      <ContextTooltipRow name={language.t("context.usage.cost")} value={cost()} />
+      <ContextTooltipRow name={language.t("context.usage.usage")} value={`${context()?.usage ?? 0}%`} />
+      <ContextTooltipRow
+        name={language.t("context.usage.tokens")}
+        value={getSessionTokenTotal(tokens())?.toLocaleString(language.intl()) ?? "0"}
+      />
     </div>
   )
 
   return (
     <Show when={params.id}>
-      <Tooltip value={tooltipValue()} placement={props.placement ?? "top"}>
+      <TooltipV2 value={tooltipValue()} placement={props.placement ?? "top"} shift={-8}>
         <Switch>
           <Match when={variant() === "indicator"}>{circle()}</Match>
+          <Match when={buttonAppearance() === "v2"}>
+            <IconButtonV2
+              type="button"
+              variant="ghost-muted"
+              size="large"
+              icon={circleV2()}
+              onClick={openContext}
+              aria-label={language.t("context.usage.view")}
+            />
+          </Match>
           <Match when={true}>
             <Button
               type="button"
@@ -125,7 +159,7 @@ export function SessionContextUsage(props: SessionContextUsageProps) {
             </Button>
           </Match>
         </Switch>
-      </Tooltip>
+      </TooltipV2>
     </Show>
   )
 }