Guest API WebSocket connection drops immediately after auth handshake

Trying to build a custom chat UI in Blazor Server instead of using the standard widget. The docs say I can use the WebSocket API for real-time messaging. I’m following the auth flow from the platform guide, but the connection dies right after I send the auth message.

Here’s the C# code using System.Net.WebSockets:

var socket = new ClientWebSocket();
await socket.ConnectAsync(new Uri("wss://api.mypurecloud.com/api/v2/conversations/messaging/channels/ws"), CancellationToken.None);

var authPayload = JsonSerializer.Serialize(new {
 type = "auth",
 token = _accessToken
});

await socket.SendAsync(Encoding.UTF8.GetBytes(authPayload), WebSocketMessageType.Text, true, CancellationToken.None);

// Receive handshake response
var buffer = new byte[1024];
var result = await socket.ReceiveAsync(buffer, CancellationToken.None);
var response = Encoding.UTF8.GetString(buffer, 0, result.Count);

The response comes back as {"type":"auth-success"}. But the next ReceiveAsync call throws WebSocketException: The remote party closed the WebSocket connection without completing the close handshake. within 500ms. I haven’t sent a join message yet. Is there a keep-alive requirement I’m missing? Or does the server drop idle connections instantly? The docs don’t mention a timeout for the initial handshake phase.

You’re hitting the common WebSocket auth trap. The Genesys Cloud WebSocket API doesn’t use the standard HTTP header auth. You need to send a specific JSON message as the very first frame after the TCP connection is established, before the server even opens the channel for data. If you don’t send that auth message within a few seconds, the server kills the connection.

The payload needs your bearer token, which you get from the standard OAuth2 client_credentials or authorization_code flow first. Don’t try to pass the token in the URL or headers for the WebSocket upgrade itself. It has to be the first application-level message.

Here’s the exact JSON structure you need to send immediately after ConnectAsync succeeds in your C# code:

{
 "action": "auth",
 "token": "your_oauth_bearer_token_here",
 "client": "custom-blazor-ui",
 "version": "1.0"
}

In your Node.js integrations, I use the ws library and it’s the same pattern. Connect, then ws.send(JSON.stringify(authPayload)). You’ll get a {"action": "auth", "status": "success"} response back before you can do anything else.

Also, make sure your token has the conversation:read scope if you’re just listening, or conversation:write if you’re sending messages. The WebSocket server validates the scopes on that auth handshake. If the scope is missing, it won’t give you a nice error message, it’ll just drop the connection.

One other thing, the endpoint is wss://api.mypurecloud.com/api/v2/conversations/websocket. Make sure you’re not hitting the old v1 endpoint or the analytics websocket, which has a different auth flow entirely. The v2 conversation websocket is the one that handles real-time message streams for chat, voice, and email.

Double-check your token expiry too. If you’re using a short-lived token, you’ll need to handle re-authentication when the token expires. The server will send a {"action": "auth", "status": "expired"} message. You’ll need to catch that, get a new token, and send the auth message again. It’s a bit of a dance, but it works reliably once you get the timing right.