feat: add configurable activity-aware ACP request timeout

packages/core/README.md

@@ -136,8 +136,8 @@ await vm.dispose();
 ### Exported Types
 
 **VM & Options**
-- `AgentOsOptions` — VM creation options (commandDirs, loopbackExemptPorts, moduleAccessCwd, mounts, additionalInstructions)
-- `CreateSessionOptions` — Session options (cwd, env, mcpServers, skipOsInstructions, additionalInstructions)
+- `AgentOsOptions` — VM creation options (software, loopbackExemptPorts, moduleAccessCwd, rootFilesystem, mounts, additionalInstructions, scheduleDriver, toolKits, permissions, acpTimeoutMs)
+- `CreateSessionOptions` — Session options (cwd, env, mcpServers, skipOsInstructions, additionalInstructions, acpTimeoutMs)
 
 **Mount Configurations**
 - `MountConfig` — Union of all mount types

packages/core/src/acp-client.ts

@@ -4,13 +4,13 @@ import {
 	isRequest,
 	isResponse,
 	type JsonRpcError,
-	type JsonRpcRequest,
 	type JsonRpcNotification,
+	type JsonRpcRequest,
 	type JsonRpcResponse,
 	serializeMessage,
 } from "./protocol.js";
 
-const DEFAULT_TIMEOUT_MS = 120_000;
+const DEFAULT_TIMEOUT_MS = 900_000; // 15 minutes
 const EXIT_DRAIN_GRACE_MS = 50;
 const LEGACY_PERMISSION_METHOD = "request/permission";
 const ACP_PERMISSION_METHOD = "session/request_permission";
@@ -22,6 +22,7 @@ interface PendingRequest {
 	resolve: (response: JsonRpcResponse) => void;
 	reject: (error: Error) => void;
 	timer: ReturnType<typeof setTimeout>;
+	method: string;
 }
 
 interface PendingPermissionRequest {
@@ -31,9 +32,7 @@ interface PendingPermissionRequest {
 }
 
 export type NotificationHandler = (notification: JsonRpcNotification) => void;
-export type InboundRequestHandler = (
-	request: JsonRpcRequest,
-) =>
+export type InboundRequestHandler = (request: JsonRpcRequest) =>
 	| Promise<
 			| {
 					result?: unknown;
@@ -52,14 +51,17 @@ export type InboundRequestHandler = (
 export class AcpClient {
 	private _process: ManagedProcess;
 	private _nextId = 1;
-	private _pending = new Map<number | string | null, PendingRequest>();
+	private _pending = new Map<number, PendingRequest>();
 	private _seenInboundRequestIds = new Set<number | string | null>();
 	private _notificationHandlers: NotificationHandler[] = [];
 	private _closed = false;
 	private _timeoutMs: number;
 	private _stdoutIterator: AsyncIterator<string> | null = null;
 	private _readerClosed = false;
-	private _pendingPermissionRequests = new Map<string, PendingPermissionRequest>();
+	private _pendingPermissionRequests = new Map<
+		string,
+		PendingPermissionRequest
+	>();
 	private _requestHandler?: InboundRequestHandler;
 	private _recentActivity: string[] = [];
 
@@ -72,7 +74,13 @@ export class AcpClient {
 		},
 	) {
 		this._process = process;
-		this._timeoutMs = options?.timeoutMs ?? DEFAULT_TIMEOUT_MS;
+		const timeoutMs = options?.timeoutMs ?? DEFAULT_TIMEOUT_MS;
+		if (timeoutMs <= 0) {
+			throw new Error(
+				`ACP timeoutMs must be a positive number, got ${timeoutMs}`,
+			);
+		}
+		this._timeoutMs = timeoutMs;
 		this._requestHandler = options?.requestHandler;
 		this._startReading(stdoutLines);
 		this._watchExit();
@@ -102,7 +110,7 @@ export class AcpClient {
 				reject(this._createTimeoutError(method, id));
 			}, this._timeoutMs);
 
-			this._pending.set(id, { resolve, reject, timer });
+			this._pending.set(id, { resolve, reject, timer, method });
 		});
 
 		if (method !== ACP_CANCEL_METHOD) {
@@ -167,9 +175,11 @@ export class AcpClient {
 					this._recordActivity(summarizeInboundMessage(msg));
 
 					if (isResponse(msg)) {
-						const pending = this._pending.get(msg.id);
-						if (pending) {
-							this._pending.delete(msg.id);
+						const id = typeof msg.id === "number" ? msg.id : undefined;
+						const pending =
+							id !== undefined ? this._pending.get(id) : undefined;
+						if (id !== undefined && pending) {
+							this._pending.delete(id);
 							clearTimeout(pending.timer);
 							pending.resolve(msg);
 						}
@@ -180,6 +190,10 @@ export class AcpClient {
 							handler(msg);
 						}
 					}
+
+					// Reset inactivity timers for remaining pending requests
+					// whenever any valid JSON-RPC message arrives from the agent.
+					this._resetPendingTimers();
 				}
 			} catch {
 				// Stream ended or errored
@@ -244,11 +258,10 @@ export class AcpClient {
 				id: msg.id,
 				method: msg.method,
 				options: Array.isArray(requestParams.options)
-					? requestParams.options
-							.filter(
-								(option): option is Record<string, unknown> =>
-									option !== null && typeof option === "object",
-							)
+					? requestParams.options.filter(
+							(option): option is Record<string, unknown> =>
+								option !== null && typeof option === "object",
+						)
 					: undefined,
 			});
 			const params = {
@@ -354,6 +367,22 @@ export class AcpClient {
 		}
 	}
 
+	/**
+	 * Reset all pending request inactivity timers. Called after any
+	 * valid inbound JSON-RPC message to implement activity-aware timeout.
+	 * Replaces each timer with a fresh one starting from now.
+	 */
+	private _resetPendingTimers(): void {
+		if (this._closed) return;
+		for (const [id, pending] of this._pending) {
+			clearTimeout(pending.timer);
+			pending.timer = setTimeout(() => {
+				this._pending.delete(id);
+				pending.reject(this._createTimeoutError(pending.method, id));
+			}, this._timeoutMs);
+		}
+	}
+
 	private _createTimeoutError(method: string, id: number | string): Error {
 		const processState = `process exitCode=${String(
 			this._getProcessExitCode(),