fb.event Cross-Window Events

fb.event emits application-defined events to connected windows. Subscribe to those event names through fb.on(), fb.once(), or fb.off(); the handler receives { payload, sourceWindowId }, the value the sender gave and the ID of the window that sent it.

emit(eventName, payload?, excludeSelf?)

Signature: fb.event.emit(eventName: string, payload?: JsonValue, excludeSelf?: boolean): Promise<EventEmitResponse>

Broadcasts an event to every connected window. Set excludeSelf to true to omit the originating window; it defaults to false.

await fb.event.emit('theme:accentChanged', { color: '#4cc2ff' }, true);

emitTo(eventName, payload, targetWindowId)

Signature: fb.event.emitTo(eventName: string, payload: JsonValue, targetWindowId: string): Promise<EventEmitToResponse>

Parameter	Type	Required	Description
eventName	string	Yes	Custom event name
payload	unknown	Yes	JSON-serializable event payload; null arrives as {}
targetWindowId	string	Yes	Destination window ID, such as main or a windowId a port reports

Sends the event to one window only. Fails with NOT_FOUND, details carrying targetWindowId, when no open window has that ID.

await fb.event.emitTo(
	'theme:focusSearch',
	{ selectAll: true },
	targetWindowId
);