changeset spawn input required

.changeset/big-pumas-search.md

@@ -0,0 +1,22 @@
+---
+'xstate': patch
+---
+
+Make `spawn` input required when defined inside referenced actor:
+
+```ts
+const childMachine = createMachine({
+  types: { input: {} as { value: number } }
+});
+
+const machine = createMachine({
+  types: {} as { context: { ref: ActorRefFrom<typeof childMachine> } },
+  context: ({ spawn }) => ({
+    ref: spawn(
+      childMachine,
+      // Input is now required!
+      { input: { value: 42 } }
+    )
+  })
+});
+```