Trying to build a custom chat UI using the Guest API WebSocket endpoint instead of the standard widget. The initial HTTP request to /api/v2/webchat/visitors/.../channels returns a 200 OK with the connection ID, but when I upgrade to WebSocket, it drops instantly with a 1006 error. No useful error message in the logs. Is there a specific header or payload required for the WebSocket upgrade that isn’t documented? Here’s the fetch setup I’m using:
Hey, that 1006 is a classic silent killer. It usually means the server closed the connection without sending a close frame, which often happens when the WebSocket handshake headers are slightly off or the URL scheme doesn’t match the endpoint expectation.
The Guest API WebSocket endpoint is finicky about the protocol. If you’re hitting wss:// you need to make sure the origin header matches your registered domain, and more importantly, you aren’t trying to send a JSON payload in the WebSocket open message itself. The handshake is just HTTP.
Check your WebSocket constructor. It should look like this:
const wsUrl = `wss://${deploymentId}.webchat.genesyscloud.com/api/v2/webchat/visitors/${visitorId}/channels/${channelId}/websocket`;
const socket = new WebSocket(wsUrl, [
'genesys-cloud-webchat',
`visitor-id=${visitorId}`
]);
socket.onopen = () => {
console.log('Connection established');
// Send the initial join message ONLY after open
socket.send(JSON.stringify({
type: 'join',
visitorId: visitorId,
channelId: channelId
}));
};
socket.onerror = (error) => {
console.error('WebSocket error:', error);
};
The key bit is passing the subprotocol genesys-cloud-webchat and the visitor ID as a custom header in the constructor array. If you omit that, the server rejects the upgrade silently. Also, ensure you’re not sending the join message before onopen fires. That’ll drop the connection instantly.