fix: preserve services across actor start

.changeset/capture-actor-service-context.md

@@ -0,0 +1,5 @@
+---
+"@humanlayer/effect-machine": patch
+---
+
+Preserve Effect service dependencies supplied while allocating a local actor, so state effects run correctly when `actor.start` is called later.

lefthook.yml

@@ -11,3 +11,13 @@ pre-commit:
       run: bun run typecheck
     - name: test
       run: bun run test
+
+pre-push:
+  parallel: true
+  jobs:
+    - name: fmt
+      run: bun run fmt:check
+    - name: lint
+      run: bun run lint
+    - name: typecheck
+      run: bun run typecheck

src/actor.ts

@@ -772,6 +772,7 @@ export const createActor = Effect.fn("effect-machine.actor.spawn")(function* <
   },
 ) {
   const lifecycle: Lifecycle<S, E> | undefined = options?.lifecycle;
+  const serviceContext = yield* Effect.context<R>();
 
   // Spawn is cold — initial state from hydrate or machine.initial.
   // Recovery runs during start, not allocate.
@@ -998,7 +999,11 @@ export const createActor = Effect.fn("effect-machine.actor.spawn")(function* <
     if (implicitSystemScope !== undefined) {
       yield* Scope.close(implicitSystemScope, Exit.void);
     }
-  }).pipe(Effect.withSpan("effect-machine.actor.stop"), Effect.asVoid);
+  }).pipe(
+    Effect.provide(serviceContext),
+    Effect.withSpan("effect-machine.actor.stop"),
+    Effect.asVoid,
+  );
 
   // Track whether hydrate was provided — skip recovery when hydrated
   const isHydrated = options?.initialState !== undefined;
@@ -1078,7 +1083,11 @@ export const createActor = Effect.fn("effect-machine.actor.spawn")(function* <
     if (currentRuntime !== undefined) {
       yield* currentRuntime.start;
     }
-  }).pipe(Effect.withSpan("effect-machine.actor.start"), Effect.asVoid);
+  }).pipe(
+    Effect.provide(serviceContext),
+    Effect.withSpan("effect-machine.actor.start"),
+    Effect.asVoid,
+  );
 
   return buildActorRefCore(
     id,

src/internal/runtime.ts

@@ -222,8 +222,8 @@ export const createRuntime = Effect.fn("effect-machine.runtime.create")(function
 ) {
   const { actorId, hooks, lifecycle } = config;
 
-  // Capture context for fire-and-forget Deferred settlement (runForkWith)
-  const services = yield* Effect.context();
+  // Capture services at allocation so start, stop, and deferred settlement retain them.
+  const services = yield* Effect.context<R>();
   const fork = Effect.runForkWith(services);
 
   // Resources: use cell-provided or allocate fresh
@@ -494,8 +494,8 @@ export const createRuntime = Effect.fn("effect-machine.runtime.create")(function
 
   return {
     ...makeHandle(stateRef, stoppedRef, eventQueue, exitDeferred, actorScope),
-    stop,
-    start,
+    stop: stop.pipe(Effect.provide(services)),
+    start: start.pipe(Effect.provide(services)),
   };
 });
 

test/services.test.ts

@@ -70,6 +70,10 @@ const streamMachine = Machine.make({
   )
   .final(StreamState.Done);
 
+const GreetingLive = Layer.succeed(GreetingService, {
+  greet: (name) => Effect.succeed(`Hello, ${name}!`),
+});
+
 describe("service requirements", () => {
   it.scopedLive("runs state tasks with services supplied by a Layer", () =>
     Effect.gen(function* () {
@@ -105,6 +109,17 @@ describe("service requirements", () => {
     ),
   );
 
+  it.scopedLive("preserves services provided around actor allocation for start", () =>
+    Effect.gen(function* () {
+      const actor = yield* Machine.spawn(streamMachine).pipe(Effect.provide(GreetingLive));
+      yield* actor.start;
+      yield* actor.send(StreamEvent.Start);
+
+      const state = yield* actor.awaitFinal;
+      expect(state).toEqual(StreamState.Done({ message: "Hello, Grace!" }));
+    }),
+  );
+
   it.scopedLive("propagates service requirements through ActorSystem.spawn", () =>
     Effect.gen(function* () {
       const system = yield* ActorSystemService;