feat: add session token authentication for IPC socket

assistant/src/__tests__/__snapshots__/ipc-snapshot.test.ts.snap

@@ -1,4 +1,11 @@
-// Bun Snapshot v1, https://goo.gl/fbAQLP
+// Bun Snapshot v1, https://bun.sh/docs/test/snapshots
+
+exports[`IPC message snapshots ClientMessage types auth serializes to expected JSON 1`] = `
+{
+  "token": "abc123def456",
+  "type": "auth",
+}
+`;
 
 exports[`IPC message snapshots ClientMessage types user_message serializes to expected JSON 1`] = `
 {
@@ -375,6 +382,13 @@ exports[`IPC message snapshots ClientMessage types apps_list serializes to expec
 }
 `;
 
+exports[`IPC message snapshots ClientMessage types home_base_get serializes to expected JSON 1`] = `
+{
+  "ensureLinked": true,
+  "type": "home_base_get",
+}
+`;
+
 exports[`IPC message snapshots ClientMessage types shared_apps_list serializes to expected JSON 1`] = `
 {
   "type": "shared_apps_list",
@@ -540,6 +554,21 @@ exports[`IPC message snapshots ClientMessage types integration_disconnect serial
 }
 `;
 
+exports[`IPC message snapshots ServerMessage types auth_result serializes to expected JSON 1`] = `
+{
+  "success": true,
+  "type": "auth_result",
+}
+`;
+
+exports[`IPC message snapshots ServerMessage types user_message_echo serializes to expected JSON 1`] = `
+{
+  "sessionId": "sess-001",
+  "text": "Check the weather for me",
+  "type": "user_message_echo",
+}
+`;
+
 exports[`IPC message snapshots ServerMessage types assistant_text_delta serializes to expected JSON 1`] = `
 {
   "sessionId": "sess-001",
@@ -1256,6 +1285,43 @@ exports[`IPC message snapshots ServerMessage types apps_list_response serializes
 }
 `;
 
+exports[`IPC message snapshots ServerMessage types home_base_get_response serializes to expected JSON 1`] = `
+{
+  "homeBase": {
+    "appId": "home-base-001",
+    "onboardingTasks": [
+      "Make it mine",
+      "Enable voice mode",
+      "Enable computer control",
+      "Try ambient mode",
+    ],
+    "preview": {
+      "description": "Prebuilt onboarding + starter task canvas",
+      "icon": "🏠",
+      "metrics": [
+        {
+          "label": "Starter tasks",
+          "value": "3",
+        },
+        {
+          "label": "Onboarding tasks",
+          "value": "4",
+        },
+      ],
+      "subtitle": "Dashboard",
+      "title": "Home Base",
+    },
+    "source": "prebuilt_seed",
+    "starterTasks": [
+      "Change the look and feel",
+      "Research something for me about X",
+      "Turn it into a webpage or interactive UI",
+    ],
+  },
+  "type": "home_base_get_response",
+}
+`;
+
 exports[`IPC message snapshots ServerMessage types shared_apps_list_response serializes to expected JSON 1`] = `
 {
   "apps": [
@@ -1502,58 +1568,6 @@ exports[`IPC message snapshots ServerMessage types integration_connect_result se
 }
 `;
 
-exports[`IPC message snapshots ClientMessage types home_base_get serializes to expected JSON 1`] = `
-{
-  "ensureLinked": true,
-  "type": "home_base_get",
-}
-`;
-
-exports[`IPC message snapshots ServerMessage types home_base_get_response serializes to expected JSON 1`] = `
-{
-  "homeBase": {
-    "appId": "home-base-001",
-    "onboardingTasks": [
-      "Make it mine",
-      "Enable voice mode",
-      "Enable computer control",
-      "Try ambient mode",
-    ],
-    "preview": {
-      "description": "Prebuilt onboarding + starter task canvas",
-      "icon": "🏠",
-      "metrics": [
-        {
-          "label": "Starter tasks",
-          "value": "3",
-        },
-        {
-          "label": "Onboarding tasks",
-          "value": "4",
-        },
-      ],
-      "subtitle": "Dashboard",
-      "title": "Home Base",
-    },
-    "source": "prebuilt_seed",
-    "starterTasks": [
-      "Change the look and feel",
-      "Research something for me about X",
-      "Turn it into a webpage or interactive UI",
-    ],
-  },
-  "type": "home_base_get_response",
-}
-`;
-
-exports[`IPC message snapshots ServerMessage types user_message_echo serializes to expected JSON 1`] = `
-{
-  "sessionId": "sess-001",
-  "text": "Check the weather for me",
-  "type": "user_message_echo",
-}
-`;
-
 exports[`IPC message snapshots ServerMessage types app_files_changed serializes to expected JSON 1`] = `
 {
   "appId": "app-001",

assistant/src/__tests__/ipc-snapshot.test.ts

@@ -17,6 +17,10 @@ import type {
 
 type ClientMessageType = ClientMessage['type'];
 const clientMessages: Record<ClientMessageType, ClientMessage> = {
+  auth: {
+    type: 'auth',
+    token: 'abc123def456',
+  },
   user_message: {
     type: 'user_message',
     sessionId: 'sess-001',
@@ -354,6 +358,10 @@ const clientMessages: Record<ClientMessageType, ClientMessage> = {
 
 type ServerMessageType = ServerMessage['type'];
 const serverMessages: Record<ServerMessageType, ServerMessage> = {
+  auth_result: {
+    type: 'auth_result',
+    success: true,
+  },
   user_message_echo: {
     type: 'user_message_echo',
     text: 'Check the weather for me',

assistant/src/__tests__/ipc-validate.test.ts

@@ -312,6 +312,7 @@ describe('IPC Validate', () => {
   describe('contract parity', () => {
     // Minimal valid payloads for high-risk message types that require extra fields
     const HIGH_RISK_FIXTURES: Record<string, Record<string, unknown>> = {
+      auth: { token: 'abc123' },
       user_message: { sessionId: 's1', content: 'hi' },
       confirmation_response: { requestId: 'r1', decision: 'allow' },
       secret_response: { requestId: 'r1' },

assistant/src/cli.ts

@@ -2,7 +2,7 @@ import * as net from 'node:net';
 import * as readline from 'node:readline';
 import { readFileSync, appendFileSync, mkdirSync } from 'node:fs';
 import { dirname } from 'node:path';
-import { getSocketPath, getHistoryPath } from './util/platform.js';
+import { getSocketPath, getHistoryPath, readSessionToken } from './util/platform.js';
 import {
   serialize,
   createMessageParser,
@@ -656,17 +656,40 @@ export async function startCli(): Promise<void> {
       parser = createMessageParser();
       const newSocket = net.createConnection(socketPath);
       let connected = false;
+      let authenticated = false;
 
       newSocket.on('connect', () => {
         connected = true;
         socket = newSocket;
-        startHeartbeat();
-        resolve();
+
+        // Authenticate with session token before the server will
+        // accept any other messages.
+        const token = readSessionToken();
+        if (!token) {
+          reject(new Error('Session token not found — is the daemon running?'));
+          newSocket.destroy();
+          return;
+        }
+        newSocket.write(serialize({ type: 'auth', token }));
       });
 
       newSocket.on('data', (data) => {
         const messages = parser.feed(data.toString()) as ServerMessage[];
         for (const msg of messages) {
+          // Wait for auth_result before processing other messages
+          if (!authenticated) {
+            if (msg.type === 'auth_result') {
+              if ((msg as { success: boolean }).success) {
+                authenticated = true;
+                startHeartbeat();
+                resolve();
+              } else {
+                reject(new Error((msg as { message?: string }).message ?? 'Authentication failed'));
+                newSocket.destroy();
+              }
+            }
+            continue;
+          }
           handleMessage(msg);
         }
       });

assistant/src/daemon/handlers/index.ts

@@ -107,13 +107,15 @@ export {
 // ─── Typed dispatch ──────────────────────────────────────────────────────────
 
 type MessageType = ClientMessage['type'];
+// 'auth' is handled at the transport layer (server.ts) and never reaches dispatch.
+type DispatchableType = Exclude<MessageType, 'auth'>;
 type MessageOfType<T extends MessageType> = Extract<ClientMessage, { type: T }>;
 type MessageHandler<T extends MessageType> = (
   msg: MessageOfType<T>,
   socket: net.Socket,
   ctx: HandlerContext,
 ) => void | Promise<void>;
-type DispatchMap = { [T in MessageType]: MessageHandler<T> };
+type DispatchMap = { [T in DispatchableType]: MessageHandler<T> };
 
 const handlers: DispatchMap = {
   user_message: handleUserMessage,
@@ -226,6 +228,9 @@ export function handleMessage(
   socket: net.Socket,
   ctx: HandlerContext,
 ): void {
+  // 'auth' is handled at the transport layer and should never reach dispatch.
+  if (msg.type === 'auth') return;
+
   const handler = handlers[msg.type] as
     | ((msg: ClientMessage, socket: net.Socket, ctx: HandlerContext) => void)
     | undefined;

assistant/src/daemon/ipc-contract-inventory.json

@@ -5,6 +5,7 @@
     "AppOpenRequest",
     "AppUpdatePreviewRequest",
     "AppsListRequest",
+    "AuthMessage",
     "BundleAppRequest",
     "CancelRequest",
     "ConfirmationResponse",
@@ -78,6 +79,7 @@
     "AppsListResponse",
     "AssistantTextDelta",
     "AssistantThinkingDelta",
+    "AuthResult",
     "BundleAppResponse",
     "ConfirmationRequest",
     "ContextCompacted",
@@ -157,6 +159,7 @@
     "app_open_request",
     "app_update_preview",
     "apps_list",
+    "auth",
     "bundle_app",
     "cancel",
     "confirmation_response",
@@ -230,6 +233,7 @@
     "apps_list_response",
     "assistant_text_delta",
     "assistant_thinking_delta",
+    "auth_result",
     "bundle_app_response",
     "confirmation_request",
     "context_compacted",

assistant/src/daemon/ipc-contract.ts

@@ -80,6 +80,11 @@ export interface SessionSwitchRequest {
   sessionId: string;
 }
 
+export interface AuthMessage {
+  type: 'auth';
+  token: string;
+}
+
 export interface PingMessage {
   type: 'ping';
 }
@@ -633,6 +638,7 @@ export interface AppFilesChanged {
 }
 
 export type ClientMessage =
+  | AuthMessage
   | UserMessage
   | ConfirmationResponse
   | SecretResponse
@@ -815,6 +821,12 @@ export interface ErrorMessage {
   message: string;
 }
 
+export interface AuthResult {
+  type: 'auth_result';
+  success: boolean;
+  message?: string;
+}
+
 export interface PongMessage {
   type: 'pong';
 }
@@ -1472,6 +1484,7 @@ export interface UiSurfaceUndoResult {
 }
 
 export type ServerMessage =
+  | AuthResult
   | UserMessageEcho
   | AssistantTextDelta
   | AssistantThinkingDelta

assistant/src/daemon/ipc-validate.ts

@@ -61,6 +61,13 @@ export function isClientMessageEnvelope(value: unknown): value is ClientMessage
 type PropertyValidator = (obj: Record<string, unknown>) => string | null;
 
 const HIGH_RISK_VALIDATORS: Record<string, PropertyValidator> = {
+  auth: (obj) => {
+    if (typeof obj.token !== 'string' || obj.token === '') {
+      return 'auth requires a non-empty string "token"';
+    }
+    return null;
+  },
+
   user_message: (obj) => {
     if (typeof obj.sessionId !== 'string' || obj.sessionId === '') {
       return 'user_message requires a non-empty string "sessionId"';