Fail Codex resume requests explicitly (#947)

packages/server/src/server/agent/providers/codex-app-server-agent.test.ts

@@ -35,6 +35,7 @@ interface CollaborationModeRecord {
 }
 
 interface CodexSessionTestAccess {
+  ensureThreadLoaded(): Promise<void>;
   handleToolApprovalRequest(params: unknown): Promise<unknown>;
   handleNotification(method: string, params: unknown): void;
   loadPersistedHistory(): Promise<void>;
@@ -378,6 +379,80 @@ describe("Codex app-server provider", () => {
     });
   });
 
+  test("resumeSession does not replace a persisted Codex thread when app-server resume fails", async () => {
+    const threadRequests: string[] = [];
+    const appServer = createFakeCodexAppServer({
+      "thread/loaded/list": () => {
+        threadRequests.push("thread/loaded/list");
+        return { data: [] };
+      },
+      "thread/resume": () => {
+        threadRequests.push("thread/resume");
+        return Promise.reject(new Error("no rollout found for thread id archived-thread-id"));
+      },
+      "thread/start": () => {
+        threadRequests.push("thread/start");
+        return { thread: { id: "replacement-empty-thread-id" } };
+      },
+      "thread/read": () => {
+        threadRequests.push("thread/read");
+        return { thread: { turns: [] } };
+      },
+      getUserSavedConfig: () => {
+        threadRequests.push("getUserSavedConfig");
+        return { config: {} };
+      },
+      "config/read": () => {
+        threadRequests.push("config/read");
+        return { config: {} };
+      },
+      "model/list": () => {
+        threadRequests.push("model/list");
+        return {
+          data: [{ id: "gpt-5.4", isDefault: true, defaultReasoningEffort: "medium" }],
+        };
+      },
+    });
+    const provider = new CodexAppServerAgentClient(createTestLogger());
+    castInternals<{ goalsEnabledPromise: Promise<boolean> | null }>(provider).goalsEnabledPromise =
+      Promise.resolve(false);
+    castInternals<{ spawnAppServer: () => Promise<ChildProcessWithoutNullStreams> }>(
+      provider,
+    ).spawnAppServer = async () => appServer.child;
+
+    const outcome = await Promise.race([
+      provider
+        .resumeSession({
+          sessionId: "archived-thread-id",
+          metadata: {
+            cwd: "/tmp/codex-question-test",
+            modeId: "auto",
+            model: "gpt-5.4",
+          },
+        })
+        .then(
+          () => "resolved" as const,
+          (error) => {
+            expect(error).toBeInstanceOf(Error);
+            expect((error as Error).message).toContain(
+              "no rollout found for thread id archived-thread-id",
+            );
+            return "rejected" as const;
+          },
+        ),
+      new Promise<"timed_out">((resolve) => setTimeout(() => resolve("timed_out"), 500)),
+    ]);
+
+    if (outcome === "timed_out") {
+      appServer.child.kill("SIGTERM");
+      throw new Error(`resumeSession timed out; thread requests: ${threadRequests.join(", ")}`);
+    }
+
+    expect(threadRequests).toEqual(["thread/loaded/list", "thread/resume"]);
+    expect(outcome).toBe("rejected");
+    appServer.assertNoErrors();
+  });
+
   test("lists repo skills using WorkspaceGitService repo-root resolution", async () => {
     const tempDir = await mkdtemp(path.join(tmpdir(), "codex-skills-"));
     const cwd = path.join(tempDir, "repo", "packages", "app");
@@ -1134,6 +1209,37 @@ describe("Codex app-server provider", () => {
     ]);
   });
 
+  test("does not replace a persisted Codex thread when app-server resume fails", async () => {
+    const session = createSession({ thinkingOptionId: "medium" });
+    session.currentThreadId = "archived-thread-id";
+    const requests: Array<{ method: string; params: unknown }> = [];
+    session.client = {
+      request: vi.fn(async (method: string, params: unknown) => {
+        requests.push({ method, params });
+        if (method === "thread/loaded/list") {
+          return { data: [] };
+        }
+        if (method === "thread/resume") {
+          throw new Error("no rollout found for thread id archived-thread-id");
+        }
+        if (method === "thread/start") {
+          return { thread: { id: "replacement-empty-thread-id" } };
+        }
+        return {};
+      }),
+    };
+
+    await expect(asInternals(session).ensureThreadLoaded()).rejects.toThrow(
+      "no rollout found for thread id archived-thread-id",
+    );
+
+    expect(session.currentThreadId).toBe("archived-thread-id");
+    expect(requests).toEqual([
+      { method: "thread/loaded/list", params: {} },
+      { method: "thread/resume", params: { threadId: "archived-thread-id" } },
+    ]);
+  });
+
   test("appends blank-line spacing to /goal status messages", async () => {
     const requests: Array<{ method: string; params: unknown }> = [];
     const session = createSession({}, { goalsEnabled: true });

packages/server/src/server/agent/providers/codex-app-server-agent.ts

@@ -2987,9 +2987,10 @@ class CodexAppServerAgentSession implements AgentSession {
       }
       await this.client.request("thread/resume", params);
     } catch (error) {
-      this.logger.warn({ error }, "Failed to resume Codex thread, starting new thread");
-      this.currentThreadId = null;
-      await this.ensureThread();
+      const threadId = this.currentThreadId;
+      const message = error instanceof Error ? error.message : String(error);
+      this.logger.warn({ error, threadId }, "Failed to resume persisted Codex thread");
+      throw new Error(`Failed to resume Codex thread ${threadId}: ${message}`, { cause: error });
     }
   }
 

packages/server/src/server/daemon-client.e2e.test.ts

@@ -151,7 +151,7 @@ function waitForSignal<T>(
 
 class NonPersistentReloadSession implements AgentSession {
   readonly provider = "claude" as const;
-  readonly id = null;
+  readonly id: string | null;
   readonly capabilities = {
     supportsStreaming: false,
     supportsSessionPersistence: true,
@@ -161,7 +161,12 @@ class NonPersistentReloadSession implements AgentSession {
     supportsToolInvocations: false,
   } as const;
 
-  constructor(private readonly onClose: () => void) {}
+  constructor(
+    private readonly onClose: () => void,
+    id: string | null = null,
+  ) {
+    this.id = id;
+  }
 
   async run(): Promise<AgentRunResult> {
     return {
@@ -259,6 +264,37 @@ class NonPersistentReloadClient implements AgentClient {
   }
 }
 
+class FailingResumeSession extends NonPersistentReloadSession {
+  constructor(onClose: () => void) {
+    super(onClose, "failing-resume-session");
+  }
+
+  describePersistence(): AgentPersistenceHandle | null {
+    return {
+      provider: "claude",
+      sessionId: this.id,
+      metadata: { cwd: process.cwd() },
+    };
+  }
+}
+
+class FailingResumeClient extends NonPersistentReloadClient {
+  async createSession(_config: AgentSessionConfig): Promise<AgentSession> {
+    this.createSessionCalls += 1;
+    return new FailingResumeSession(() => {
+      this.closeCalls += 1;
+    });
+  }
+
+  async resumeSession(
+    _handle: AgentPersistenceHandle,
+    _overrides?: Partial<AgentSessionConfig>,
+  ): Promise<AgentSession> {
+    this.resumeSessionCalls += 1;
+    throw new Error("resume exploded");
+  }
+}
+
 function resolveSpeechConfig() {
   if (hasLocalSpeech) {
     return {
@@ -482,6 +518,36 @@ test("refresh_agent rebuilds a live agent even when it has no persistence handle
   }
 });
 
+test("refresh_agent rejects when persisted session resume fails", async () => {
+  const cwd = tmpCwd();
+  const client = new FailingResumeClient();
+  const localCtx = await createDaemonTestContext({
+    agentClients: {
+      claude: client,
+    },
+  });
+
+  try {
+    const created = await localCtx.client.createAgent({
+      config: {
+        provider: "claude",
+        cwd,
+      },
+    });
+    await localCtx.client.archiveAgent(created.id);
+
+    await expect(localCtx.client.refreshAgent(created.id)).rejects.toMatchObject({
+      name: "DaemonRpcError",
+      code: "agent_refresh_failed",
+      requestType: "refresh_agent_request",
+    });
+    expect(client.resumeSessionCalls).toBe(1);
+  } finally {
+    await localCtx.cleanup();
+    rmSync(cwd, { recursive: true, force: true });
+  }
+});
+
 test("resume_agent auto-unarchives archived agents", async () => {
   const cwd = tmpCwd();
   try {

packages/server/src/server/session.ts

@@ -3085,6 +3085,17 @@ export class Session {
     const { handle, overrides, requestId } = msg;
     if (!handle) {
       this.sessionLogger.warn("Resume request missing persistence handle");
+      if (requestId) {
+        this.emit({
+          type: "rpc_error",
+          payload: {
+            requestId,
+            requestType: msg.type,
+            error: "Unable to resume agent: missing persistence handle",
+            code: "agent_resume_failed",
+          },
+        });
+      }
       this.emit({
         type: "activity_log",
         payload: {
@@ -3121,14 +3132,26 @@ export class Session {
         });
       }
     } catch (error) {
+      const message = getErrorMessage(error);
       this.sessionLogger.error({ err: error }, "Failed to resume agent");
+      if (requestId) {
+        this.emit({
+          type: "rpc_error",
+          payload: {
+            requestId,
+            requestType: msg.type,
+            error: message,
+            code: "agent_resume_failed",
+          },
+        });
+      }
       this.emit({
         type: "activity_log",
         payload: {
           id: uuidv4(),
           timestamp: new Date(),
           type: "error",
-          content: `Failed to resume agent: ${getErrorMessage(error)}`,
+          content: `Failed to resume agent: ${message}`,
         },
       });
     }
@@ -3249,14 +3272,26 @@ export class Session {
         });
       }
     } catch (error) {
+      const message = getErrorMessage(error);
       this.sessionLogger.error({ err: error, agentId }, `Failed to refresh agent ${agentId}`);
+      if (requestId) {
+        this.emit({
+          type: "rpc_error",
+          payload: {
+            requestId,
+            requestType: msg.type,
+            error: message,
+            code: "agent_refresh_failed",
+          },
+        });
+      }
       this.emit({
         type: "activity_log",
         payload: {
           id: uuidv4(),
           timestamp: new Date(),
           type: "error",
-          content: `Failed to refresh agent: ${getErrorMessage(error)}`,
+          content: `Failed to refresh agent: ${message}`,
         },
       });
     }