feat(companion): add known event name typing and listing

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()`) and event helpers (`subscribeEvents()`, `subscribeEvent()`, `subscribeAgentStream()`, `subscribeAgentTyping()`, `subscribeContextWarning()`, `waitForEvent()` with timeout/predicate/abort support and deterministic teardown cancellation, `waitForAnyEvent()`, `waitForAgentStream()`, `waitForAgentTyping()`, `waitForContextWarning()`, `clearEventSubscriptions()`).
+- `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()`) and event helpers (`subscribeEvents()`, `subscribeEvent()`, `subscribeAgentStream()`, `subscribeAgentTyping()`, `subscribeContextWarning()`, `waitForEvent()` with timeout/predicate/abort support and deterministic teardown cancellation, `waitForAnyEvent()`, `waitForAgentStream()`, `waitForAgentTyping()`, `waitForContextWarning()`, `clearEventSubscriptions()`, `listKnownEventNames()`).
 - `src/companion/platformClients.ts` provides platform-focused wrappers:
   - `MacOSCompanionClient` (`platform: "macos"`, APNs push registration)
   - `IOSCompanionClient` (`platform: "ios"`, APNs push registration)

docs/plans/state.json

@@ -633,6 +633,20 @@
       ],
       "test_status": "pnpm test:run src/companion/platformClients.test.ts src/companion/runtimeClient.test.ts src/companion/heartbeatLoop.test.ts src/companion/platformClients.integration.test.ts + pnpm typecheck passing"
     },
+    "companion-runtime-known-event-names": {
+      "status": "completed",
+      "date": "2026-02-17",
+      "updated": "2026-02-17",
+      "summary": "Added typed companion event-name contract (`CompanionEventName`) and `listKnownEventNames()` helper for discoverable event surfaces in companion clients.",
+      "files_modified": [
+        "src/companion/runtimeClient.ts",
+        "src/companion/runtimeClient.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"
+    },
     "browser-tools-activation-clarity": {
       "status": "completed",
       "date": "2026-02-17",

src/companion/index.ts

@@ -14,6 +14,7 @@ export type {
   CompanionRuntimeClientOptions,
   CompanionEventHandler,
   CompanionTypedEventHandler,
+  CompanionEventName,
   CompanionEventPredicate,
   CompanionEventEnvelope,
   RegisterNodeInput,

src/companion/runtimeClient.test.ts

@@ -224,6 +224,18 @@ describe('CompanionRuntimeClient', () => {
     expect(typingHandler).toHaveBeenCalledWith({ active: true });
   });
 
+  it('lists known companion event names', () => {
+    const client = new CompanionRuntimeClient({
+      url: 'ws://127.0.0.1:1',
+    });
+
+    expect(client.listKnownEventNames()).toEqual([
+      'agent.stream',
+      'agent.typing',
+      'context_warning',
+    ]);
+  });
+
   it('supports subscribeContextWarning helper', () => {
     const client = new CompanionRuntimeClient({
       url: 'ws://127.0.0.1:1',

src/companion/runtimeClient.ts

@@ -54,6 +54,8 @@ export const COMPANION_EVENT_NAMES = {
   agentTyping: 'agent.typing',
   contextWarning: 'context_warning',
 } as const;
+export type CompanionEventName =
+  (typeof COMPANION_EVENT_NAMES)[keyof typeof COMPANION_EVENT_NAMES];
 
 export interface RegisterNodeInput {
   nodeId: string;
@@ -388,7 +390,7 @@ export class CompanionRuntimeClient {
   }
 
   subscribeEvent<TData = unknown>(
-    eventName: string,
+    eventName: CompanionEventName | string,
     handler: CompanionTypedEventHandler<TData>,
   ): () => void {
     return this.subscribeEvents((event, data) => {
@@ -418,7 +420,7 @@ export class CompanionRuntimeClient {
   }
 
   waitForEvent<TData = unknown>(
-    eventName: string,
+    eventName: CompanionEventName | string,
     options?: {
       timeoutMs?: number;
       predicate?: CompanionEventPredicate<TData>;
@@ -480,7 +482,7 @@ export class CompanionRuntimeClient {
   }
 
   waitForAnyEvent<TData = unknown>(
-    eventNames: readonly string[],
+    eventNames: readonly (CompanionEventName | string)[],
     options?: {
       timeoutMs?: number;
       predicate?: (event: string, data: TData) => boolean;
@@ -573,6 +575,10 @@ export class CompanionRuntimeClient {
     return this.waitForEvent<TData>(COMPANION_EVENT_NAMES.contextWarning, options);
   }
 
+  listKnownEventNames(): CompanionEventName[] {
+    return Object.values(COMPANION_EVENT_NAMES);
+  }
+
   async call<T>(method: string, params?: Record<string, unknown>): Promise<T> {
     if (!this.connected) {
       if (!this.autoConnect) {