feat(companion): add connection snapshot helper

README.md

@@ -1190,7 +1190,7 @@ Methods:
 - `system.capabilities` returns gateway protocol and node policy snapshot.
 
 Companion runtime helper:
-- `src/companion/runtimeClient.ts` provides a typed Node/WebSocket client for companion runtimes (macOS/iOS/Android workers) with wrappers for `node.register`, `node.capabilities.get`, `node.location.set/get`, `node.status.set`, `node.push_token.set`, `system.capabilities`, `system.nodes`, and canvas artifact RPCs (`canvas.put/get/list/delete/clear`), plus convenience helpers (`bootstrapNode`, optional `autoConnect`, `dispose()`, `waitForIdle()` for pending-work drain synchronization) and event helpers (`subscribeEvents()`, `subscribeEvent()`, `subscribeAgentStream()`, `subscribeAgentTyping()`, `subscribeContextWarning()`, `waitForEvent()` with timeout/predicate/abort support plus event-name/timeout validation and deterministic teardown cancellation including socket-close rejection, `waitForAnyEvent()` with event-list/timeout validation, `waitForAgentStream()`, `waitForAgentTyping()`, `waitForContextWarning()`, `clearEventSubscriptions()`, `cancelPendingEventWaits()` returning cancelled waiter count, `listKnownEventNames()`, `eventSubscriptionCount`) plus in-flight observability via `pendingRequestCount`, `pendingEventWaitCount`, `hasPendingWork`, `idle`, `getPendingWorkSnapshot()`, and `getEventSurfaceSnapshot()`.
+- `src/companion/runtimeClient.ts` provides a typed Node/WebSocket client for companion runtimes (macOS/iOS/Android workers) with wrappers for `node.register`, `node.capabilities.get`, `node.location.set/get`, `node.status.set`, `node.push_token.set`, `system.capabilities`, `system.nodes`, and canvas artifact RPCs (`canvas.put/get/list/delete/clear`), plus convenience helpers (`bootstrapNode`, optional `autoConnect`, `dispose()`, `waitForIdle()` for pending-work drain synchronization) and event helpers (`subscribeEvents()`, `subscribeEvent()`, `subscribeAgentStream()`, `subscribeAgentTyping()`, `subscribeContextWarning()`, `waitForEvent()` with timeout/predicate/abort support plus event-name/timeout validation and deterministic teardown cancellation including socket-close rejection, `waitForAnyEvent()` with event-list/timeout validation, `waitForAgentStream()`, `waitForAgentTyping()`, `waitForContextWarning()`, `clearEventSubscriptions()`, `cancelPendingEventWaits()` returning cancelled waiter count, `listKnownEventNames()`, `eventSubscriptionCount`) plus in-flight observability via `pendingRequestCount`, `pendingEventWaitCount`, `hasPendingWork`, `idle`, `getPendingWorkSnapshot()`, `getEventSurfaceSnapshot()`, and `getConnectionSnapshot()`.
 - `src/companion/platformClients.ts` provides platform-focused wrappers:
   - `MacOSCompanionClient` (`platform: "macos"`, APNs push registration)
   - `IOSCompanionClient` (`platform: "ios"`, APNs push registration)
@@ -1201,7 +1201,7 @@ Companion runtime helper:
   - optional `defaultSessionId` for canvas helper calls so `sessionId` can be omitted per call
   - lifecycle passthroughs for connection state/teardown (`connected`, `dispose(code?, reason?)`)
   - stream passthrough helpers (`subscribeEvents`, `subscribeEvent`, `clearEventSubscriptions`, `cancelPendingEventWaits`, `listKnownEventNames`, `eventSubscriptionCount`, `subscribeAgentStream/Typing/ContextWarning`, `waitForEvent`, `waitForAnyEvent`, `waitForAgentStream/Typing/ContextWarning`)
-  - runtime observability/control passthroughs (`pendingRequestCount`, `pendingEventWaitCount`, `hasPendingWork`, `idle`, `getPendingWorkSnapshot()`, `getEventSurfaceSnapshot()`, `connected`, `waitForIdle()`)
+  - runtime observability/control passthroughs (`pendingRequestCount`, `pendingEventWaitCount`, `hasPendingWork`, `idle`, `getPendingWorkSnapshot()`, `getEventSurfaceSnapshot()`, `getConnectionSnapshot()`, `connected`, `waitForIdle()`)
 - `src/companion/heartbeatLoop.ts` provides `CompanionHeartbeatLoop` for periodic heartbeat scheduling (`publishHeartbeat`) with start/stop safety, optional interval jitter (`jitterRatio`) to spread load (with safe normalization for invalid random samples), `tickNow()` for manual sends, success/error hooks, loop observability (`successCount`, `lastSuccessAt`, `failureCount`, `lastFailure`, `getState()`), and optional auto-stop after repeated failures.
 
 ## Canvas / A2UI Foundation

docs/plans/state.json

@@ -1056,6 +1056,22 @@
       ],
       "test_status": "pnpm test:run src/companion/runtimeClient.test.ts src/companion/platformClients.test.ts src/companion/heartbeatLoop.test.ts src/companion/platformClients.integration.test.ts + pnpm typecheck passing"
     },
+    "companion-runtime-connection-snapshot-helper": {
+      "status": "completed",
+      "date": "2026-02-17",
+      "updated": "2026-02-17",
+      "summary": "Added `getConnectionSnapshot()` on runtime and platform wrappers for one-call connection/activity snapshot (`connected`, pending counts, subscription counts, idle/busy flags).",
+      "files_modified": [
+        "src/companion/runtimeClient.ts",
+        "src/companion/runtimeClient.test.ts",
+        "src/companion/platformClients.ts",
+        "src/companion/platformClients.test.ts",
+        "src/companion/index.ts",
+        "README.md",
+        "docs/plans/state.json"
+      ],
+      "test_status": "pnpm test:run src/companion/runtimeClient.test.ts src/companion/platformClients.test.ts src/companion/heartbeatLoop.test.ts src/companion/platformClients.integration.test.ts + pnpm typecheck passing"
+    },
     "companion-runtime-cancel-pending-event-waits": {
       "status": "completed",
       "date": "2026-02-17",

src/companion/index.ts

@@ -15,6 +15,7 @@ export type {
   WaitForIdleOptions,
   PendingWorkSnapshot,
   EventSurfaceSnapshot,
+  ConnectionSnapshot,
   CompanionEventHandler,
   CompanionTypedEventHandler,
   CompanionEventName,

src/companion/platformClients.test.ts

@@ -37,6 +37,7 @@ function createRuntimeMock(): {
   waitForIdle: ReturnType<typeof vi.fn>;
   getPendingWorkSnapshot: ReturnType<typeof vi.fn>;
   getEventSurfaceSnapshot: ReturnType<typeof vi.fn>;
+  getConnectionSnapshot: ReturnType<typeof vi.fn>;
   waitForAgentStream: ReturnType<typeof vi.fn>;
   waitForAgentTyping: ReturnType<typeof vi.fn>;
   waitForContextWarning: ReturnType<typeof vi.fn>;
@@ -92,6 +93,14 @@ function createRuntimeMock(): {
     eventSubscriptionCount: 3,
     pendingEventWaitCount: 1,
   }));
+  const getConnectionSnapshot = vi.fn(() => ({
+    connected: true,
+    eventSubscriptionCount: 3,
+    pendingRequestCount: 2,
+    pendingEventWaitCount: 1,
+    hasPendingWork: true,
+    idle: false,
+  }));
   const waitForAgentStream = vi.fn(async () => ({ token: 'streamed' }));
   const waitForAgentTyping = vi.fn(async () => ({ active: true }));
   const waitForContextWarning = vi.fn(async () => ({ thresholdPct: 75, estimatedPct: 90 }));
@@ -133,6 +142,7 @@ function createRuntimeMock(): {
     waitForIdle,
     getPendingWorkSnapshot,
     getEventSurfaceSnapshot,
+    getConnectionSnapshot,
     waitForAgentStream,
     waitForAgentTyping,
     waitForContextWarning,
@@ -188,6 +198,7 @@ function createRuntimeMock(): {
     waitForIdle,
     getPendingWorkSnapshot,
     getEventSurfaceSnapshot,
+    getConnectionSnapshot,
     waitForAgentStream,
     waitForAgentTyping,
     waitForContextWarning,
@@ -417,6 +428,23 @@ describe('platform companion clients', () => {
     });
   });
 
+  it('platform getConnectionSnapshot forwards to runtime client', async () => {
+    const mock = createRuntimeMock();
+    const client = new IOSCompanionClient({ runtime: mock.runtime, nodeId: 'ios-node' });
+
+    const snapshot = client.getConnectionSnapshot();
+
+    expect(mock.getConnectionSnapshot).toHaveBeenCalledOnce();
+    expect(snapshot).toEqual({
+      connected: true,
+      eventSubscriptionCount: 3,
+      pendingRequestCount: 2,
+      pendingEventWaitCount: 1,
+      hasPendingWork: true,
+      idle: false,
+    });
+  });
+
   it('macOS client forwards canvas methods to runtime client', async () => {
     const mock = createRuntimeMock();
     const client = new MacOSCompanionClient({ runtime: mock.runtime, nodeId: 'mac-node' });

src/companion/platformClients.ts

@@ -2,6 +2,7 @@ import type {
   CompanionEventName,
   CompanionEventEnvelope,
   EventSurfaceSnapshot,
+  ConnectionSnapshot,
   CompanionEventHandler,
   CanvasClearResult,
   CanvasDeleteResult,
@@ -306,6 +307,10 @@ export class MacOSCompanionClient {
     return this.runtime.getEventSurfaceSnapshot();
   }
 
+  getConnectionSnapshot(): ConnectionSnapshot {
+    return this.runtime.getConnectionSnapshot();
+  }
+
   waitForAnyEvent<TData = unknown>(
     eventNames: readonly (CompanionEventName | string)[],
     options?: {
@@ -580,6 +585,10 @@ export class IOSCompanionClient {
     return this.runtime.getEventSurfaceSnapshot();
   }
 
+  getConnectionSnapshot(): ConnectionSnapshot {
+    return this.runtime.getConnectionSnapshot();
+  }
+
   waitForAnyEvent<TData = unknown>(
     eventNames: readonly (CompanionEventName | string)[],
     options?: {
@@ -852,6 +861,10 @@ export class AndroidCompanionClient {
     return this.runtime.getEventSurfaceSnapshot();
   }
 
+  getConnectionSnapshot(): ConnectionSnapshot {
+    return this.runtime.getConnectionSnapshot();
+  }
+
   waitForAnyEvent<TData = unknown>(
     eventNames: readonly (CompanionEventName | string)[],
     options?: {

src/companion/runtimeClient.test.ts

@@ -721,6 +721,33 @@ describe('CompanionRuntimeClient', () => {
     await pendingWait;
   });
 
+  it('returns connection snapshot', async () => {
+    const client = new CompanionRuntimeClient({
+      url: 'ws://127.0.0.1:1',
+    });
+    const pendingWait = client.waitForEvent('agent.stream', { timeoutMs: 10_000 }).catch(() => undefined);
+
+    expect(client.getConnectionSnapshot()).toEqual({
+      connected: false,
+      eventSubscriptionCount: 1,
+      pendingRequestCount: 0,
+      pendingEventWaitCount: 1,
+      hasPendingWork: true,
+      idle: false,
+    });
+
+    client.clearEventSubscriptions();
+    await pendingWait;
+    expect(client.getConnectionSnapshot()).toEqual({
+      connected: false,
+      eventSubscriptionCount: 0,
+      pendingRequestCount: 0,
+      pendingEventWaitCount: 0,
+      hasPendingWork: false,
+      idle: true,
+    });
+  });
+
   it('waitForIdle resolves immediately when no work is pending', async () => {
     const client = new CompanionRuntimeClient({
       url: 'ws://127.0.0.1:1',

src/companion/runtimeClient.ts

@@ -59,6 +59,15 @@ export interface EventSurfaceSnapshot {
   pendingEventWaitCount: number;
 }
 
+export interface ConnectionSnapshot {
+  connected: boolean;
+  eventSubscriptionCount: number;
+  pendingRequestCount: number;
+  pendingEventWaitCount: number;
+  hasPendingWork: boolean;
+  idle: boolean;
+}
+
 export type CompanionEventHandler = (event: string, data: unknown) => void;
 export type CompanionTypedEventHandler<TData = unknown> = (data: TData) => void;
 export type CompanionEventPredicate<TData = unknown> = (data: TData) => boolean;
@@ -352,6 +361,17 @@ export class CompanionRuntimeClient {
     };
   }
 
+  getConnectionSnapshot(): ConnectionSnapshot {
+    return {
+      connected: this.connected,
+      eventSubscriptionCount: this.eventSubscriptionCount,
+      pendingRequestCount: this.pendingRequestCount,
+      pendingEventWaitCount: this.pendingEventWaitCount,
+      hasPendingWork: this.hasPendingWork,
+      idle: this.idle,
+    };
+  }
+
   async connect(): Promise<void> {
     if (this.connected) {
       return;