fix(app): keep session tab labels stable during creation (#47099)

Co-authored-by: LukeParkerDev <10430890+Hona@users.noreply.github.com>

packages/app/e2e/regression/new-session-workspace-pending.spec.ts

@@ -26,6 +26,53 @@ for (const viewport of [
   { name: "desktop", width: 1280, height: 900 },
   { name: "mobile", width: 390, height: 844 },
 ]) {
+  test(`keeps Session in the tab until the generated title arrives on ${viewport.name}`, async ({ page }, testInfo) => {
+    await page.setViewportSize(viewport)
+    const mock = await openDraft(page, { untitled: true })
+    const label = page.locator(
+      viewport.name === "mobile"
+        ? '[data-slot="mobile-tab-title"]'
+        : '[data-titlebar-tab-slot][data-active="true"] [data-titlebar-tab-title]',
+    )
+    await expect(label).toHaveText("Session")
+    const pending = await submitPending(page, mock)
+    const spinner = page.locator(
+      viewport.name === "mobile"
+        ? '[data-slot="mobile-tabs-trigger"] [data-component="session-progress-indicator-v2"]'
+        : `[data-titlebar-tab-link][href="${sessionPath}${pending.sessionID}"] [data-component="session-progress-indicator-v2"]`,
+    )
+    await expect(spinner).toBeVisible()
+    await testInfo.attach("pending-tab-title", {
+      body: await page.screenshot(),
+      contentType: "image/png",
+    })
+    await expect(label).toHaveText("Session")
+
+    mock.worktree.resolve({ status: 200, json: { directory: workspace } })
+    await expect(pending.shimmer).toHaveCount(0)
+    await expect(page.locator('[data-action="composer-submit"]')).toBeEnabled()
+    await expect(label).toHaveText("Session")
+
+    if (viewport.name === "mobile") {
+      await label.click()
+      const drawer = page.locator('[data-slot="mobile-tabs-drawer"]')
+      const tab = drawer.locator(`[data-titlebar-tab-link][href="${sessionPath}${pending.sessionID}"]`)
+      await expect(tab.locator("[data-titlebar-tab-title]")).toHaveText("Session")
+      await tab.click()
+      await expect(drawer).toBeHidden()
+    }
+
+    mock.events.push({
+      id: "evt_generated_title",
+      type: "session.renamed",
+      created: Date.now(),
+      location: { directory: workspace },
+      durable: { aggregateID: pending.sessionID, seq: 1, version: 1 },
+      data: { sessionID: pending.sessionID, title: "Generated session title" },
+    })
+    await expect(label).toHaveText("Generated session title")
+  })
+
   test(`shows a pending workspace session immediately on ${viewport.name}`, async ({ page }, testInfo) => {
     await page.setViewportSize(viewport)
     const mock = await openDraft(page)
@@ -404,13 +451,14 @@ async function draftFollowUp(page: Page) {
 
 async function openDraft(
   page: Page,
-  options?: { failSessionCreate?: boolean; command?: boolean; events?: () => OpenCodeEvent[] },
+  options?: { failSessionCreate?: boolean; untitled?: boolean; command?: boolean; events?: () => OpenCodeEvent[] },
 ) {
   const worktree = Promise.withResolvers<{ status: number; json: { directory?: string; message?: string } }>()
   const calls: string[] = []
   const worktreeRequests: Record<string, unknown>[] = []
   const creates: Record<string, unknown>[] = []
   const prompts: { sessionID: string; body: Record<string, unknown> }[] = []
+  const events: OpenCodeEvent[] = []
   const project = {
     id: projectID,
     worktree: directory,
@@ -437,7 +485,7 @@ async function openDraft(
     sessions,
     pageMessages: () => ({ items: [] }),
     onPrompt: (input) => prompts.push(input),
-    events: options?.events,
+    events: options?.events ?? (() => events.splice(0)),
   })
   page.on("request", (request) => {
     if (request.method() !== "POST") return
@@ -464,7 +512,10 @@ async function openDraft(
       return route.fulfill({ status: 500, json: { message: "Session creation failed in the fixture" }, headers })
     }
     if (typeof body.id !== "string") throw new Error("Session creation must use the client-reserved ID")
-    const session = currentSession({ ...body, id: body.id, projectID, title: "Created workspace session" }, workspace)
+    const session = currentSession(
+      { ...body, id: body.id, projectID, title: options?.untitled ? "" : "Created workspace session" },
+      workspace,
+    )
     sessions.push(session)
     return route.fulfill({ json: { data: session }, headers })
   })
@@ -532,7 +583,7 @@ async function openDraft(
   await page.getByRole("menuitem", { name: "New worktree", exact: true }).click()
   await expect(page.getByRole("button", { name: "New worktree", exact: true })).toBeVisible()
   await expect(page.locator('[data-component="composer-editor"]')).toBeEditable()
-  return { worktree, worktreeRequests, calls, creates, prompts }
+  return { worktree, worktreeRequests, calls, creates, prompts, events }
 }
 
 async function submitPending(page: Page, mock: Awaited<ReturnType<typeof openDraft>>, prompt = text) {

packages/app/src/shell/titlebar/tab-nav.tsx

@@ -13,7 +13,7 @@ import { displayName, projectForSession } from "@/shell/layout/helpers"
 import { SessionTabAvatar } from "@/shell/layout/session-tab-avatar"
 import { SessionProgressIndicatorV2 } from "@opencode-ai/session-ui/v2/session-progress-indicator-v2"
 import type { SessionInfo } from "@opencode-ai/client/promise"
-import { sessionLabel } from "@/session/title"
+import { sessionTabTitle } from "./tab-title"
 import { useSettings } from "@/settings/model"
 import { canOpenTabRename, forwardTabRef } from "./tab-gesture"
 import { TabPreviewPopover } from "./tab-popover"
@@ -63,7 +63,7 @@ export function TabNavItem(props: {
   })
   const title = createMemo(() => {
     const session = props.session
-    return session ? sessionLabel(session) : props.fallbackTitle
+    return sessionTabTitle(session ? session.title : props.fallbackTitle, language.t("session.tab.session"))
   })
 
   const projectName = createMemo(() => {

packages/app/src/shell/titlebar/tab-strip.tsx

@@ -171,7 +171,7 @@ function SessionTabEntry(props: {
         preparing={!!pending()}
         fallbackTitle={
           pending()
-            ? language.t("command.session.new")
+            ? language.t("session.tab.session")
             : (persisted()?.title ?? (missingSession() ? language.t("session.tab.unknown") : undefined))
         }
         onRename={rename}

packages/app/src/shell/titlebar/tab-title.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, test } from "bun:test"
+import { sessionTabTitle } from "./tab-title"
+
+describe("session tab titles", () => {
+  test("uses the same localized label before a title arrives", () => {
+    for (const title of [
+      undefined,
+      "",
+      "New session - 2026-07-30T18:45:03.662Z",
+      "Child session - 2026-07-30T18:45:03.662Z",
+    ]) {
+      expect(sessionTabTitle(title, "Session")).toBe("Session")
+      expect(sessionTabTitle(title, "Sitzung")).toBe("Sitzung")
+    }
+  })
+
+  test("preserves generated and user-supplied titles", () => {
+    for (const title of ["Generated title", "New session", "New session - custom"]) {
+      expect(sessionTabTitle(title, "Session")).toBe(title)
+    }
+  })
+})

packages/app/src/shell/titlebar/tab-title.ts

@@ -0,0 +1,6 @@
+import { isFallbackTitle } from "@opencode-ai/util/session-title-fallback"
+
+// Draft, preparing, and untitled session tabs share one localized label.
+export function sessionTabTitle(title: string | undefined, fallback: string) {
+  return !title || isFallbackTitle(title) ? fallback : title
+}

packages/app/src/shell/titlebar/titlebar.tsx

@@ -26,7 +26,7 @@ import "./titlebar.css"
 import { newTabTooltipKeybind } from "@/shell/commands/tooltip-keybind"
 import { TitlebarRightMount } from "@/shell/titlebar/right-slot"
 import { MobileDrawer, MobileDrawerContent, MobileDrawerLabel, MobileDrawerTrigger } from "@/shell/mobile-drawer"
-import { sessionLabel } from "@/session/title"
+import { sessionTabTitle } from "./tab-title"
 import { SessionTabAvatar } from "@/shell/layout/session-tab-avatar"
 import { SessionProgressIndicatorV2 } from "@opencode-ai/session-ui/v2/session-progress-indicator-v2"
 import { projectForSession } from "@/shell/layout/helpers"
@@ -422,9 +422,12 @@ export function Titlebar(props: {
             const currentTitle = () => {
               const tab = currentTab()
               if (!tab) return language.t("home.title")
-              if (tab.type === "draft") return language.t("command.session.new")
+              if (tab.type === "draft") return language.t("session.tab.session")
               const value = session()
-              return value ? sessionLabel(value) : (tabs.info[tabKey(tab)]?.title ?? language.t("command.session.new"))
+              return sessionTabTitle(
+                value ? value.title : tabs.info[tabKey(tab)]?.title,
+                language.t("session.tab.session"),
+              )
             }
             createEffect(() => {
               path()
@@ -505,7 +508,7 @@ export function Titlebar(props: {
                             </span>
                           )}
                         </Show>
-                        <span dir="auto" class="min-w-0 flex-1 truncate text-start">
+                        <span data-slot="mobile-tab-title" dir="auto" class="min-w-0 flex-1 truncate text-start">
                           {currentTitle()}
                         </span>
                         <span class="shrink-0 text-v2-text-text-muted">{tabsStore.length}</span>