feat(app): extract prompt state and add composer model selection (#36227)

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

@@ -1335,6 +1335,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
       onQueue: props.onQueue,
       onAbort: props.onAbort,
       onSubmit: props.onSubmit,
+      model: props.controls.model.selection,
     })
 
   const handleKeyDown = (event: KeyboardEvent) => {

packages/app/src/components/prompt-input/submit.test.ts

@@ -1,5 +1,6 @@
 import { beforeAll, beforeEach, describe, expect, mock, test } from "bun:test"
 import type { Prompt } from "@/context/prompt"
+import type { ModelSelection } from "@/context/local"
 
 let createPromptSubmit: typeof import("./submit").createPromptSubmit
 
@@ -33,6 +34,10 @@ const prompt = {
   current: () => promptValue,
   cursor: () => 0,
   dirty: () => true,
+  model: {
+    current: () => undefined,
+    set: () => undefined,
+  },
   reset: () => undefined,
   set: () => undefined,
   context: {
@@ -378,6 +383,39 @@ describe("prompt submit worktree selection", () => {
     })
   })
 
+  test("uses an injected model selection", async () => {
+    params = { id: "session-1" }
+    const model = {
+      current: () => ({ id: "draft-model", provider: { id: "draft-provider" } }),
+      variant: { current: () => "draft-variant" },
+    } as unknown as ModelSelection
+    const submit = createPromptSubmit({
+      prompt,
+      info: () => ({ id: "session-1" }),
+      imageAttachments: () => [],
+      commentCount: () => 0,
+      autoAccept: () => false,
+      mode: () => "normal",
+      working: () => false,
+      editor: () => undefined,
+      queueScroll: () => undefined,
+      promptLength: (value) => value.reduce((sum, part) => sum + ("content" in part ? part.content.length : 0), 0),
+      addToHistory: () => undefined,
+      resetHistoryNavigation: () => undefined,
+      setMode: () => undefined,
+      setPopover: () => undefined,
+      model,
+    })
+
+    await submit.handleSubmit({ preventDefault: () => undefined } as unknown as Event)
+
+    expect(optimistic[0]).toMatchObject({
+      message: {
+        model: { providerID: "draft-provider", modelID: "draft-model", variant: "draft-variant" },
+      },
+    })
+  })
+
   test("seeds new sessions before optimistic prompts are added", async () => {
     const submit = createPromptSubmit({
       prompt,

packages/app/src/components/prompt-input/submit.ts

@@ -8,7 +8,7 @@ import { useTabs } from "@/context/tabs"
 import { useServerSync, type ServerSync } from "@/context/server-sync"
 import { useLanguage } from "@/context/language"
 import { useLayout } from "@/context/layout"
-import { useLocal } from "@/context/local"
+import { useLocal, type ModelSelection } from "@/context/local"
 import { usePermission } from "@/context/permission"
 import { type ContextItem, type ImageAttachmentPart, type Prompt, type usePrompt } from "@/context/prompt"
 import { useSDK, type DirectorySDK } from "@/context/sdk"
@@ -191,6 +191,7 @@ type PromptSubmitInput = {
   onQueue?: (draft: FollowupDraft) => void
   onAbort?: () => void
   onSubmit?: () => void
+  model?: ModelSelection
 }
 
 export function createPromptSubmit(input: PromptSubmitInput) {
@@ -298,9 +299,10 @@ export function createPromptSubmit(input: PromptSubmitInput) {
       return
     }
 
-    const currentModel = local.model.current()
+    const modelSelection = input.model ?? local.model
+    const currentModel = modelSelection.current()
     const currentAgent = local.agent.current()
-    const variant = local.model.variant.current()
+    const variant = modelSelection.variant.current()
     if (!currentModel || !currentAgent) {
       showToast({
         title: language.t("prompt.toast.modelAgentRequired.title"),
@@ -377,7 +379,11 @@ export function createPromptSubmit(input: PromptSubmitInput) {
         await startTransition(() => {
           if (!session) return
           if (shouldAutoAccept) permission.enableAutoAccept(session.id, sessionDirectory)
-          local.session.promote(sessionDirectory, session.id)
+          local.session.promote(sessionDirectory, session.id, {
+            agent: currentAgent.name,
+            model: { providerID: currentModel.provider.id, modelID: currentModel.id },
+            variant: variant ?? null,
+          })
           layout.handoff.setTabs(base64Encode(sessionDirectory), session.id)
           const draftID = search.draftId
           if (draftID) tabs.promoteDraft(draftID, { server: tabs.draft(draftID).server, sessionId: session.id })

packages/app/src/components/titlebar.tsx

@@ -25,6 +25,7 @@ import { readSessionTabsRemovedDetail, SESSION_TABS_REMOVED_EVENT } from "@/comp
 import { useGlobal } from "@/context/global"
 import { ServerConnection, useServer } from "@/context/server"
 import { tabKey, useTabs } from "@/context/tabs"
+import type { PromptSession } from "@/context/prompt"
 import "./titlebar.css"
 import { newTabTooltipKeybind } from "./command-tooltip-keybind"
 
@@ -324,13 +325,20 @@ export function Titlebar(props: { update?: TitlebarUpdate }) {
               const route = layout.route()
               const activeSession = session()
               if (route.type === "session" && activeSession) {
-                tabs.newDraft({ server: route.server ?? server.key, directory: activeSession.directory }, "")
+                const sessionTab = {
+                  type: "session" as const,
+                  server: route.server ?? server.key,
+                  sessionId: activeSession.id,
+                }
+                const model = tabs.stateValue<PromptSession>(sessionTab, "prompt")?.model.current()
+                tabs.newDraft({ server: sessionTab.server, directory: activeSession.directory }, "", model)
                 return
               }
 
               const activeTab = currentTab()
               if (activeTab?.type === "draft") {
-                tabs.newDraft({ server: activeTab.server, directory: activeTab.directory }, "")
+                const model = tabs.stateValue<PromptSession>(activeTab, "prompt")?.model.current()
+                tabs.newDraft({ server: activeTab.server, directory: activeTab.directory }, "", model)
                 return
               }