fix(server): let OpenCode generate session titles (#13368)

Co-authored-by: Yash Singh <saiansh2525@gmail.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

Author: 3 people

apps/server/src/orchestration/Layers/ProviderCommandReactor.test.ts

@@ -891,8 +891,92 @@ describe("ProviderCommandReactor", () => {
     expect(thread?.session?.threadId).toBe("thread-1");
     expect(thread?.session?.status).toBe("starting");
     expect(thread?.session?.runtimeMode).toBe("approval-required");
+    expect(harness.startSession.mock.calls[0]?.[1]).not.toHaveProperty("title");
   });
 
+  effectIt.effect("forwards only a user-renamed title when starting a provider session", () =>
+    Effect.gen(function* () {
+      const harness = yield* Effect.promise(() =>
+        createHarness({ initialTitle: "Add a progressive blur as you scroll" }),
+      );
+      const now = "2026-01-01T00:00:00.000Z";
+      const modelSelection = {
+        instanceId: ProviderInstanceId.make("codex"),
+        model: "gpt-5-codex",
+      };
+      const startTurn = (threadId: string, text: string, titleSeed: string) =>
+        harness.engine.dispatch({
+          type: "thread.turn.start",
+          commandId: CommandId.make(`cmd-title-${threadId}`),
+          threadId: ThreadId.make(threadId),
+          message: {
+            messageId: asMessageId(`message-${threadId}`),
+            role: "user",
+            text,
+            attachments: [],
+          },
+          titleSeed,
+          interactionMode: DEFAULT_PROVIDER_INTERACTION_MODE,
+          runtimeMode: "approval-required",
+          createdAt: now,
+        });
+
+      yield* startTurn(
+        "thread-1",
+        "Add a progressive blur as you scroll",
+        "Add a progressive blur as you scroll",
+      );
+      yield* Effect.promise(() => waitFor(() => harness.startSession.mock.calls.length === 1));
+      expect(harness.startSession.mock.calls[0]?.[1]).not.toHaveProperty("title");
+
+      yield* harness.engine.dispatch({
+        type: "thread.create",
+        commandId: CommandId.make("cmd-thread-create-renamed"),
+        threadId: ThreadId.make("thread-renamed"),
+        projectId: asProjectId("project-1"),
+        title: "New thread",
+        modelSelection,
+        interactionMode: DEFAULT_PROVIDER_INTERACTION_MODE,
+        runtimeMode: "approval-required",
+        branch: null,
+        worktreePath: null,
+        createdAt: now,
+      });
+      yield* harness.engine.dispatch({
+        type: "thread.meta.update",
+        commandId: CommandId.make("cmd-thread-rename"),
+        threadId: ThreadId.make("thread-renamed"),
+        title: "Keep this name",
+      });
+      yield* startTurn("thread-renamed", "hello there", "hello there");
+      yield* Effect.promise(() => waitFor(() => harness.startSession.mock.calls.length === 2));
+      expect(harness.startSession.mock.calls[1]?.[1]).toMatchObject({ title: "Keep this name" });
+
+      yield* harness.engine.dispatch({
+        type: "thread.create",
+        commandId: CommandId.make("cmd-thread-create-seeded"),
+        threadId: ThreadId.make("thread-seeded"),
+        projectId: asProjectId("project-1"),
+        title: "New thread",
+        modelSelection,
+        interactionMode: DEFAULT_PROVIDER_INTERACTION_MODE,
+        runtimeMode: "approval-required",
+        branch: null,
+        worktreePath: null,
+        createdAt: now,
+      });
+      yield* harness.engine.dispatch({
+        type: "thread.meta.update",
+        commandId: CommandId.make("cmd-thread-autotitle"),
+        threadId: ThreadId.make("thread-seeded"),
+        title: "hello there",
+      });
+      yield* startTurn("thread-seeded", "hello there", "hello there");
+      yield* Effect.promise(() => waitFor(() => harness.startSession.mock.calls.length === 3));
+      expect(harness.startSession.mock.calls[2]?.[1]).not.toHaveProperty("title");
+    }),
+  );
+
   effectIt.effect("projects inline context before sending the provider turn", () =>
     Effect.gen(function* () {
       const harness = yield* Effect.promise(() => createHarness());

apps/server/src/orchestration/Layers/ProviderCommandReactor.ts

@@ -575,6 +575,9 @@ const make = Effect.gen(function* () {
     options?: {
       readonly modelSelection?: ModelSelection;
       readonly pendingTurnStart?: boolean;
+      // First-turn prompt seed. A manual title that still equals this seed was
+      // written by the client's auto-title, not a user rename.
+      readonly titleSeed?: string;
     },
   ) {
     const thread = yield* resolveThreadShell(threadId);
@@ -712,6 +715,15 @@ const make = Effect.gen(function* () {
           .refreshWorkspaceSnapshot({ instanceId: desiredInstanceId, cwd: effectiveCwd })
           .pipe(Effect.forkDetach)
       : Effect.void;
+    // OpenCode skips SessionPrompt.ensureTitle when session.create already has
+    // a title. Prompt seeds and "New thread" are not user titles, so omit them
+    // and let the provider generate one. A real rename is source "manual" and
+    // differs from the first-turn prompt seed (the web client writes that seed
+    // through thread.meta.update, which also marks the title manual).
+    const manualTitle = thread.titleState?.source === "manual" ? thread.title.trim() : "";
+    const promptSeed = options?.titleSeed?.trim();
+    const sessionTitle =
+      manualTitle.length > 0 && manualTitle !== promptSeed ? thread.title : undefined;
 
     const startProviderSession = (input?: {
       readonly resumeCursor?: unknown;
@@ -723,7 +735,7 @@ const make = Effect.gen(function* () {
           ...(preferredProvider ? { provider: preferredProvider } : {}),
           providerInstanceId: desiredInstanceId,
           ...(effectiveCwd ? { cwd: effectiveCwd } : {}),
-          ...(thread.title ? { title: thread.title } : {}),
+          ...(sessionTitle ? { title: sessionTitle } : {}),
           modelSelection: desiredModelSelection,
           ...(input?.resumeCursor !== undefined ? { resumeCursor: input.resumeCursor } : {}),
           runtimeMode: desiredRuntimeMode,
@@ -839,6 +851,7 @@ const make = Effect.gen(function* () {
     readonly modelSelection?: ModelSelection;
     readonly interactionMode?: "default" | "plan";
     readonly createdAt: string;
+    readonly titleSeed?: string;
   }) {
     const thread = yield* resolveThreadShell(input.threadId);
     if (!thread) {
@@ -848,6 +861,7 @@ const make = Effect.gen(function* () {
     }
     yield* ensureSessionForThread(input.threadId, input.createdAt, {
       ...(input.modelSelection !== undefined ? { modelSelection: input.modelSelection } : {}),
+      ...(input.titleSeed !== undefined ? { titleSeed: input.titleSeed } : {}),
       pendingTurnStart: true,
     });
     if (input.modelSelection !== undefined) {
@@ -1488,6 +1502,11 @@ const make = Effect.gen(function* () {
         : {}),
       interactionMode: event.payload.interactionMode,
       createdAt: event.payload.createdAt,
+      // Later turns must not reuse the current title as titleSeed. Only the
+      // first prompt seed should suppress a not-yet-renamed session title.
+      ...(!hasOtherUserMessages && event.payload.titleSeed !== undefined
+        ? { titleSeed: event.payload.titleSeed }
+        : {}),
     }).pipe(
       Effect.asSome,
       Effect.catchCause((cause) => handleTurnStartFailure(cause).pipe(Effect.as(Option.none()))),