Acknowledgements

Request-response pattern over WebSocket. Send a message and receive a confirmation callback with automatic timeout.

Client → Server

// Client sends with callback
client.send(
  { type: "save-profile", payload: { name: "Alex" } },
  (err, response) => {
    if (err) {
      console.error("Save failed or timed out:", err.message);
    } else {
      console.log("Profile saved:", response);
    }
  }
);

Server responds

// Inside namespace connection handler
nsSocket.on("save-profile", (msg) => {
  const ackId = (msg as any).__ackId;
  if (ackId) {
    // Process and send ack response
    saveToDb(msg.payload);
    nsSocket.sendAck(ackId, { success: true, id: 123 });
  }
});

Timeout

Acks time out after 10 seconds by default. Configure via ackTimeout in client options:

const client = new PPClient({
  url: "ws://localhost:3000",
  ackTimeout: 5000,  // 5 seconds
});

Next: Connection State Recovery