Wait for Cursor ACP slash commands before listing. (#1099)

cursor-agent publishes commands asynchronously via available_commands_update, so listCommands() returned an empty cache when called right after session/new. Enable waitForInitialCommands only on CursorACPAgentClient with a 10s timeout; other ACP providers keep the immediate-return default.

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/server/src/server/agent/providers/acp-agent.test.ts

@@ -1416,7 +1416,27 @@ describe("transformPiModels", () => {
 
 describe("ACPAgentSession slash commands", () => {
   test("returns immediately for ACP sessions that do not wait for async command discovery", async () => {
-    const session = createSession();
+    const session = new ACPAgentSession(
+      {
+        provider: "claude-acp",
+        cwd: "/tmp/paseo-acp-test",
+      },
+      {
+        provider: "claude-acp",
+        logger: createTestLogger(),
+        defaultCommand: ["claude", "--acp"],
+        defaultModes: [],
+        capabilities: {
+          supportsStreaming: true,
+          supportsSessionPersistence: true,
+          supportsDynamicModes: true,
+          supportsMcpServers: true,
+          supportsReasoningStream: true,
+          supportsToolInvocations: true,
+        },
+        waitForInitialCommands: false,
+      },
+    );
 
     await expect(session.listCommands()).resolves.toEqual([]);
   });

packages/server/src/server/agent/providers/cursor-acp-agent.ts

@@ -14,6 +14,7 @@ interface CursorACPAgentClientOptions {
 }
 
 const CURSOR_MODELS_TIMEOUT_MS = 10_000;
+const CURSOR_INITIAL_COMMANDS_WAIT_TIMEOUT_MS = 10_000;
 const CURSOR_MODEL_MARKER_PATTERN = /\s+\((?:default|current)\)$/;
 
 export class CursorACPAgentClient extends GenericACPAgentClient {
@@ -21,7 +22,16 @@ export class CursorACPAgentClient extends GenericACPAgentClient {
   private readonly env?: Record<string, string>;
 
   constructor(options: CursorACPAgentClientOptions) {
-    super(options);
+    super({
+      logger: options.logger,
+      command: options.command,
+      env: options.env,
+      providerId: options.providerId,
+      label: options.label,
+      // cursor-agent publishes slash commands asynchronously via available_commands_update.
+      waitForInitialCommands: true,
+      initialCommandsWaitTimeoutMs: CURSOR_INITIAL_COMMANDS_WAIT_TIMEOUT_MS,
+    });
     this.cursorCommand = options.command;
     this.env = options.env;
   }

packages/server/src/server/agent/providers/generic-acp-agent.ts

@@ -27,6 +27,8 @@ interface GenericACPAgentClientOptions {
   env?: Record<string, string>;
   providerId?: string;
   label?: string;
+  waitForInitialCommands?: boolean;
+  initialCommandsWaitTimeoutMs?: number;
 }
 
 export class GenericACPAgentClient extends ACPAgentClient {
@@ -42,6 +44,8 @@ export class GenericACPAgentClient extends ACPAgentClient {
         env: options.env,
       },
       defaultCommand: options.command,
+      waitForInitialCommands: options.waitForInitialCommands,
+      initialCommandsWaitTimeoutMs: options.initialCommandsWaitTimeoutMs,
     });
 
     this.command = options.command;