AIDK API Reference / aidk/state / watchComState

Function: watchComState()

function watchComState<T>(key: string, defaultValue?: T): ReadonlySignal<T | undefined>;

Defined in: packages/core/src/state/use-state.ts:127

Creates a read-only signal that watches COM state.

Use this when you want to observe state that another component owns, without being able to modify it. The signal updates automatically when the COM state changes.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Description
key	string	The COM state key to watch
defaultValue?	T	Default value if state doesn't exist

Returns

ReadonlySignal<T | undefined>

Example

class ObserverComponent extends Component {
  // Watch timeline state owned by another component
  private timeline = watchComState<COMTimelineEntry[]>('timeline');

  // Can create derived values
  private messageCount = computed(() => this.timeline()?.length ?? 0);

  render() {
    // Can read
    return <div>Messages: {this.messageCount()}</div>;

    // Cannot write - no .set() or .update()
    // this.timeline.set([...])  // ❌ Not available
  }
}