By name: serverpod-server-events description: Serverpod message system — postMessage, addListener, createStream, global messages via Redis. Use when coordinating streams, sharing state across servers, or pub/sub messaging.
Serverpod Server Events
Event messaging via session.messages on named channels. Messages must be serializable models. Local by default; global (cross-server) with Redis.
Sending
await session.messages.postMessage('user_updates', UserUpdate(...));
// Cross-server (requires Redis):
await session.messages.postMessage('user_updates', message, global: true);
Posting with global: true throws if Redis is not enabled. Fall back to local messages only when cross-server delivery is not required.
Receiving
Stream:
var stream = session.messages.createStream<UserUpdate>('user_updates');
stream.listen((message) => print('Received: $message'));
If a message on the channel is not of type T, the stream emits an error. Use exact serializable types or a deliberate shared base type.
Listener:
session.messages.addListener<UserUpdate>('user_updates', (message) {
print('Received: $message');
});
Both receive local and global messages. Streams/listeners are removed when the session closes. Remove manually with session.messages.removeListener(channel, callback). Models support inheritance, which is useful when wanting a fully typed interface for server events.