fix(tui): stabilize compaction completion (#36435)

packages/tui/src/component/prompt/index.tsx

@@ -57,7 +57,7 @@ import { usePromptMove } from "./move"
 import { readLocalAttachment } from "./local-attachment"
 import { useData } from "../../context/data"
 import { useLocation } from "../../context/location"
-import { lastAssistantWithUsage } from "../../util/session"
+import { contextUsage } from "../../util/session"
 
 registerOpencodeSpinner()
 
@@ -280,21 +280,20 @@ export function Prompt(props: PromptProps) {
     if (!props.sessionID) return
     const session = data.session.get(props.sessionID)
     if (!session) return
-    const last = lastAssistantWithUsage(data.session.message.list(props.sessionID), session.revert?.messageID)
-    if (!last) return
-
-    const tokens =
-      last.tokens.input + last.tokens.output + last.tokens.reasoning + last.tokens.cache.read + last.tokens.cache.write
-    if (tokens <= 0) return
-
-    const model = data.location.model
-      .list(session.location)
-      ?.find((model) => model.providerID === last.model.providerID && model.id === last.model.id)
-    const pct = model?.limit.context ? `${Math.round((tokens / model.limit.context) * 100)}%` : undefined
     const cost = data.session.cost(props.sessionID)
+    const formattedCost = cost > 0 ? money.format(cost) : undefined
+    const context = contextUsage(
+      data.session.message.list(props.sessionID),
+      data.location.model.list(session.location),
+      session.revert?.messageID,
+    )
     return {
-      context: pct ? `${Locale.number(tokens)} (${pct})` : Locale.number(tokens),
-      cost: cost > 0 ? money.format(cost) : undefined,
+      context: context
+        ? context.percent === undefined
+          ? Locale.number(context.tokens)
+          : `${Locale.number(context.tokens)} (${context.percent}%)`
+        : undefined,
+      cost: formattedCost,
     }
   })
 

packages/tui/src/context/data.tsx

@@ -669,16 +669,12 @@ export const { use: useData, provider: DataProvider } = createSimpleContext({
             const position = draft.findLastIndex((item) => item.type === "compaction" && item.status === "running")
             const current = draft[position]
             if (current?.type === "compaction") {
-              draft[position] = {
-                id: current.id,
-                type: "compaction",
+              Object.assign(current, {
                 status: "completed",
                 reason: event.data.reason,
                 summary: event.data.text,
                 recent: event.data.recent,
-                metadata: current.metadata,
-                time: current.time,
-              }
+              })
               return
             }
             message.append(draft, index, {

packages/tui/src/feature-plugins/sidebar/context.tsx

@@ -1,8 +1,8 @@
 import type { TuiPlugin, TuiPluginApi } from "@opencode-ai/plugin/tui"
 import type { BuiltinTuiPlugin } from "../builtins"
-import { createMemo } from "solid-js"
+import { createMemo, Show } from "solid-js"
 import { useData } from "../../context/data"
-import { lastAssistantWithUsage } from "../../util/session"
+import { contextUsage } from "../../util/session"
 
 const id = "internal:sidebar-context"
 
@@ -18,33 +18,23 @@ function View(props: { api: TuiPluginApi; session_id: string }) {
   const session = createMemo(() => data.session.get(props.session_id))
   const cost = createMemo(() => data.session.cost(props.session_id))
 
-  const state = createMemo(() => {
-    const last = lastAssistantWithUsage(msg(), session()?.revert?.messageID)
-    if (!last) {
-      return {
-        tokens: 0,
-        percent: null,
-      }
-    }
-
-    const tokens =
-      last.tokens.input + last.tokens.output + last.tokens.reasoning + last.tokens.cache.read + last.tokens.cache.write
-    const model = data.location
-      .model.list(session()?.location)
-      ?.find((model) => model.providerID === last.model.providerID && model.id === last.model.id)
-    return {
-      tokens,
-      percent: model?.limit.context ? Math.round((tokens / model.limit.context) * 100) : null,
-    }
-  })
+  const state = createMemo(() => contextUsage(msg(), data.location.model.list(session()?.location), session()?.revert?.messageID))
 
   return (
     <box>
       <text fg={theme().text}>
         <b>Context</b>
       </text>
-      <text fg={theme().textMuted}>{state().tokens.toLocaleString()} tokens</text>
-      <text fg={theme().textMuted}>{state().percent ?? 0}% used</text>
+      <Show when={state()} fallback={<text fg={theme().textMuted}>Not measured</text>}>
+        {(value) => (
+          <>
+            <text fg={theme().textMuted}>{value().tokens.toLocaleString()} tokens</text>
+            <Show when={value().percent !== undefined}>
+              <text fg={theme().textMuted}>{value().percent}% used</text>
+            </Show>
+          </>
+        )}
+      </Show>
       <text fg={theme().textMuted}>{money.format(cost())} spent</text>
     </box>
   )

packages/tui/src/routes/session/index.tsx

@@ -1325,23 +1325,18 @@ function SessionSkillMessage(props: { message: Extract<SessionMessageInfo, { typ
   )
 }
 
-function CompactionMessage(props: {
-  message?: Extract<SessionMessageInfo, { type: "compaction" }>
-  status?: "running"
-  text?: string
-}) {
+function CompactionMessage(props: { message: Extract<SessionMessageInfo, { type: "compaction" }> }) {
   const ctx = use()
   const kv = useKV()
   const { theme, syntax } = useTheme()
-  const status = () => props.message?.status ?? props.status
-  const text = () =>
-    props.message?.status === "failed" ? props.message.error.message : (props.message?.summary ?? props.text ?? "")
-  const color = () => (status() === "failed" ? theme.error : status() === "completed" ? theme.success : theme.textMuted)
-  const border = color
+  const status = () => props.message.status
+  const text = () => (props.message.status === "failed" ? props.message.error.message : props.message.summary)
+  const content = createMemo(() => text().trim())
+  const color = () => (status() === "failed" ? theme.error : theme.textMuted)
   return (
     <box>
       <box flexDirection="row" alignItems="center">
-        <box border={["top"]} borderColor={border()} flexGrow={1} />
+        <box border={["top"]} borderColor={color()} flexGrow={1} />
         <box flexDirection="row" gap={1} paddingLeft={1} paddingRight={1}>
           <Switch>
             <Match when={status() === "running"}>
@@ -1349,24 +1344,21 @@ function CompactionMessage(props: {
                 <spinner frames={SPINNER_FRAMES} interval={80} color={color()} />
               </Show>
             </Match>
-            <Match when={status() === "completed"}>
-              <text fg={color()}>✓</text>
-            </Match>
             <Match when={status() === "failed"}>
               <text fg={color()}>✗</text>
             </Match>
           </Switch>
           <text fg={color()}>Compaction</text>
         </box>
-        <box border={["top"]} borderColor={border()} flexGrow={1} />
+        <box border={["top"]} borderColor={color()} flexGrow={1} />
       </box>
-      <Show when={text().trim()}>
+      <Show when={content()}>
         <box paddingTop={1} paddingLeft={3}>
           <markdown
             syntaxStyle={syntax()}
-            streaming={status() === "running"}
+            streaming={true}
             internalBlockMode="top-level"
-            content={text().trim()}
+            content={content()}
             tableOptions={{ style: "grid" }}
             conceal={ctx.conceal()}
             fg={theme.markdownText}

packages/tui/src/routes/session/rows.ts

@@ -88,7 +88,6 @@ export function createSessionRows(sessionID: Accessor<string>) {
                   {
                     id: message.id,
                     created: message.time.created,
-                    input: message.status === "running",
                   },
                 ]
               : [],
@@ -183,7 +182,9 @@ export function createSessionRows(sessionID: Accessor<string>) {
   }
   const subscriptions = [
     data.on("session.input.admitted", input),
-    data.on("session.compaction.started", message),
+    data.on("session.compaction.started", (event) => {
+      if (event.data.sessionID === sessionID()) appendMessage(event.data.inputID ?? event.id.replace(/^evt_/, "msg_"))
+    }),
     data.on("session.instructions.updated", message),
     data.on("session.synthetic", (event) => {
       if (event.data.sessionID === sessionID() && event.data.description?.trim())
@@ -192,9 +193,6 @@ export function createSessionRows(sessionID: Accessor<string>) {
     data.on("session.shell.started", message),
     data.on("session.agent.selected", message),
     data.on("session.model.selected", message),
-    data.on("session.compaction.ended", (event) => {
-      if (event.data.reason !== "manual") message(event)
-    }),
     data.on("session.text.delta", (event) => {
       if (event.data.sessionID === sessionID())
         appendPart({ messageID: event.data.assistantMessageID, partID: `text:${event.data.ordinal}` })

packages/tui/src/routes/session/subagent-footer.tsx

@@ -6,7 +6,12 @@ import { SplitBorder } from "../../ui/border"
 import { Locale } from "../../util/locale"
 import { useTerminalDimensions } from "@opentui/solid"
 import { useCommandShortcut, useOpencodeKeymap } from "../../keymap"
-import { lastAssistantWithUsage } from "../../util/session"
+import { contextUsage } from "../../util/session"
+
+const money = new Intl.NumberFormat("en-US", {
+  style: "currency",
+  currency: "USD",
+})
 
 export function SubagentFooter() {
   const route = useRouteData("session")
@@ -23,26 +28,21 @@ export function SubagentFooter() {
   const usage = createMemo(() => {
     const current = session()
     if (!current) return
-    const last = lastAssistantWithUsage(data.session.message.list(route.sessionID), current.revert?.messageID)
-    if (!last) return
-    const tokens =
-      last.tokens.input + last.tokens.output + last.tokens.reasoning + last.tokens.cache.read + last.tokens.cache.write
-    if (tokens <= 0) return
-
-    const model = data.location
-      .model.list(current.location)
-      ?.find((model) => model.providerID === last.model.providerID && model.id === last.model.id)
-    const pct = model?.limit.context ? `${Math.round((tokens / model.limit.context) * 100)}%` : undefined
-    const cost = data.session.cost(route.sessionID)
-
-    const money = new Intl.NumberFormat("en-US", {
-      style: "currency",
-      currency: "USD",
-    })
+    const cost = current.cost
+    const formattedCost = cost > 0 ? money.format(cost) : undefined
+    const context = contextUsage(
+      data.session.message.list(route.sessionID),
+      data.location.model.list(current.location),
+      current.revert?.messageID,
+    )
 
     return {
-      context: pct ? `${Locale.number(tokens)} (${pct})` : Locale.number(tokens),
-      cost: cost > 0 ? money.format(cost) : undefined,
+      context: context
+        ? context.percent === undefined
+          ? Locale.number(context.tokens)
+          : `${Locale.number(context.tokens)} (${context.percent}%)`
+        : undefined,
+      cost: formattedCost,
     }
   })
 

packages/tui/src/util/session.ts

@@ -1,4 +1,4 @@
-import type { SessionMessageAssistant, SessionMessageInfo } from "@opencode-ai/sdk/v2"
+import type { ModelInfo, SessionMessageAssistant, SessionMessageInfo } from "@opencode-ai/sdk/v2"
 
 export function isDefaultTitle(title: string) {
   return /^(New session - |Child session - )\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/.test(title)
@@ -7,8 +7,29 @@ export function isDefaultTitle(title: string) {
 export function lastAssistantWithUsage(messages: ReadonlyArray<SessionMessageInfo>, boundary?: string) {
   const boundaryIndex = boundary ? messages.findIndex((message) => message.id === boundary) : -1
   if (boundary && boundaryIndex === -1) return undefined
+  const end = boundaryIndex === -1 ? messages.length : boundaryIndex
+  const compactionIndex = messages.findLastIndex(
+    (message, index) => message.type === "compaction" && message.status === "completed" && index < end,
+  )
   return messages.findLast(
     (message, index): message is SessionMessageAssistant & { tokens: NonNullable<SessionMessageAssistant["tokens"]> } =>
-      message.type === "assistant" && message.tokens !== undefined && (boundaryIndex === -1 || index < boundaryIndex),
+      message.type === "assistant" && message.tokens !== undefined && index > compactionIndex && index < end,
   )
 }
+
+export function contextUsage(
+  messages: ReadonlyArray<SessionMessageInfo>,
+  models: ReadonlyArray<ModelInfo> | undefined,
+  boundary?: string,
+) {
+  const last = lastAssistantWithUsage(messages, boundary)
+  if (!last) return
+  const tokens =
+    last.tokens.input + last.tokens.output + last.tokens.reasoning + last.tokens.cache.read + last.tokens.cache.write
+  if (tokens <= 0) return
+  const model = models?.find((model) => model.providerID === last.model.providerID && model.id === last.model.id)
+  return {
+    tokens,
+    percent: model?.limit.context ? Math.round((tokens / model.limit.context) * 100) : undefined,
+  }
+}

packages/tui/test/cli/tui/data.test.tsx

@@ -1064,6 +1064,9 @@ test("tracks session status from active sessions and execution events", async ()
       const message = data.session.message.get("session-manual", "message-compaction")
       return message?.type === "compaction" && message.status === "running" && message.summary === "Streamed summary"
     })
+    const compactionRow = manualRows.find(
+      (row) => row.type === "message" && row.messageID === "message-compaction",
+    )
     emitEvent(events, {
       id: "evt_manual_compaction_ended",
       created: 3,
@@ -1078,6 +1081,9 @@ test("tracks session status from active sessions and execution events", async ()
     expect(manualRows.filter((row) => row.type === "message")).toEqual([
       { type: "message", messageID: "message-compaction" },
     ])
+    expect(manualRows.find((row) => row.type === "message" && row.messageID === "message-compaction")).toBe(
+      compactionRow,
+    )
 
     emitEvent(events, {
       id: "evt_compaction_started",
@@ -1102,6 +1108,9 @@ test("tracks session status from active sessions and execution events", async ()
       const message = data.session.message.get("session-live", "msg_compaction_started")
       return message?.type === "compaction" && message.status === "running" && message.summary === "Live summary"
     })
+    const autoCompactionRow = rows.find(
+      (row) => row.type === "message" && row.messageID === "msg_compaction_started",
+    )
 
     emitEvent(events, {
       id: "evt_compaction_ended",
@@ -1119,6 +1128,10 @@ test("tracks session status from active sessions and execution events", async ()
       status: "completed",
       summary: "Live summary",
     })
+    expect(rows.find((row) => row.type === "message" && row.messageID === "msg_compaction_started")).toBe(
+      autoCompactionRow,
+    )
+    expect(rows.some((row) => row.type === "message" && row.messageID === "msg_compaction_ended")).toBeFalse()
   } finally {
     app.renderer.destroy()
   }

packages/tui/test/util/session.test.ts

@@ -2,6 +2,16 @@ import { describe, expect, test } from "bun:test"
 import type { SessionMessageInfo } from "@opencode-ai/sdk/v2"
 import { isDefaultTitle, lastAssistantWithUsage } from "../../src/util/session"
 
+const assistant = (id: string, input: number): SessionMessageInfo => ({
+  id,
+  type: "assistant",
+  agent: "build",
+  model: { id: "model", providerID: "provider" },
+  content: [],
+  tokens: { input, output: 0, reasoning: 0, cache: { read: 0, write: 0 } },
+  time: { created: 0 },
+})
+
 describe("util.session", () => {
   test("recognizes generated parent and child titles", () => {
     expect(isDefaultTitle("New session - 2026-06-06T12:34:56.789Z")).toBeTrue()
@@ -10,15 +20,6 @@ describe("util.session", () => {
   })
 
   test("tracks usage across undo and redo boundaries", () => {
-    const assistant = (id: string, input: number): SessionMessageInfo => ({
-      id,
-      type: "assistant",
-      agent: "build",
-      model: { id: "model", providerID: "provider" },
-      content: [],
-      tokens: { input, output: 0, reasoning: 0, cache: { read: 0, write: 0 } },
-      time: { created: 0 },
-    })
     const messages = [assistant("msg_z", 10), assistant("msg_a", 30)]
 
     expect(lastAssistantWithUsage(messages)?.tokens.input).toBe(30)
@@ -26,4 +27,22 @@ describe("util.session", () => {
     expect(lastAssistantWithUsage(messages, "msg_missing")).toBeUndefined()
     expect(lastAssistantWithUsage(messages)?.tokens.input).toBe(30)
   })
+
+  test("resets usage at completed compaction until the next assistant reports it", () => {
+    const compaction: SessionMessageInfo = {
+      id: "msg_compaction",
+      type: "compaction",
+      status: "completed",
+      reason: "manual",
+      summary: "Current state",
+      recent: "",
+      time: { created: 0 },
+    }
+    const messages = [assistant("msg_before", 30), compaction]
+
+    expect(lastAssistantWithUsage(messages)).toBeUndefined()
+
+    messages.push(assistant("msg_after", 5))
+    expect(lastAssistantWithUsage(messages)?.tokens.input).toBe(5)
+  })
 })