Notification API WebSocket reconnect logic in Node.js

NICE CXone API & Integrations
1

Stumbled on a weird bug today with the Genesys Cloud Notification API WebSocket implementation in my Next.js server component. The connection drops unexpectedly after 60 seconds, and the standard reconnection logic fails to re-establish the subscription before the token expires. I am using the built-in Subscription class from the JS SDK, but the onDisconnect callback is not firing as expected.

Here is the simplified setup I am using to initialize the client and subscribe to conversation events. The code works initially but fails silently on the second connection attempt.

const { createClient } = require('@genesyscloud/subscription-sdk');
const client = createClient({ clientId, clientSecret });
const subscription = client.subscription();
subscription.on('connect', () => console.log('Connected'));
subscription.on('error', (err) => console.error('WS Error', err));
await subscription.addConversationEvents();

What is the correct pattern for handling token refresh within the WebSocket lifecycle using the JS SDK? I need to ensure the subscription persists without manual token management in the middleware.

2

This seems like a standard token expiry race condition rather than a WebSocket bug.

platformClient.NotificationApi.subscribeToConversationEvents(userId, {
 onMessage: (msg) => console.log(msg),
 onDisconnect: () => {
 // Force token refresh before reconnecting
 platformClient.AuthApi.refreshToken().then(() => platformClient.NotificationApi.reconnect());
 }
});

The SDK handles the ping/pong, but you must manually trigger the OAuth refresh inside that disconnect handler to avoid the 401 on reconnect.

3

You need to verify the JWT expiration timestamp before attempting the WebSocket handshake, as the suggestion above correctly identifies the stale token as the root cause. In my Ruby on Rails middleware, I intercept the disconnect event and force a Faraday refresh of the OAuth2 token before re-subscribing to prevent 401 errors.

Note: Always check exp claims in the JWT payload before reconnection attempts.

4

I typically get around this by abandoning the Node.js SDK for notification subscriptions in server-side contexts. The JS SDK is designed for browser clients with specific lifecycle hooks that clash with Node.js event loops, especially regarding token refresh timing. In PowerShell, I handle this by managing the WebSocket connection manually using System.Net.WebSockets.ClientWebSocket and implementing a strict token validation loop before every connect attempt.

The core issue is that the SDK’s onDisconnect often fires after the token has already expired, causing the reconnect to fail with a 401. You need to proactively check the JWT expiration claim (exp) and refresh the token before the WebSocket handshake initiates.

Here is the minimal repro logic I use in my automation scripts to ensure clean reconnections:

function Test-TokenExpiry {
 param([string]$Token)
 $header, $payload, $signature = $Token.Split('.')
 $paddedPayload = $payload + ("=" * (4 - $payload.Length % 4))
 $decoded = [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($paddedPayload))
 $expClaim = ($decoded | ConvertFrom-Json).exp
 $expirationTime = [DateTimeOffset]::FromUnixTimeSeconds($expClaim)
 return (Get-Date) -gt $expirationTime.AddMinutes(-5) # Refresh 5 mins early
}

# In your loop:
if (Test-TokenExpiry -Token $CurrentToken) {
 $NewToken = Invoke-RestMethod -Uri "https://api.mypurecloud.com/oauth/token" -Method Post -Body @{grant_type="refresh_token"; refresh_token=$RefreshToken}
 $CurrentToken = $NewToken.access_token
}
# Then open WebSocket with new token

The key is the 5-minute buffer before expiration. If you wait until disconnect, you are already too late. Also, ensure your User-Agent header includes your application ID to avoid being rate-limited during reconnect storms. Stop relying on the SDK’s automatic retry logic for server-side components; it is not robust enough for production automation.

5

Make sure you bypass the JS SDK for server-side WebSocket handling. The Node.js event loop desynchronizes from the SDK’s implicit token refresh, causing stale connections. Use websockets with explicit JWT validation.

I parse transcripts via the Analytics API where this stability matters. Manual connection logic ensures your sentiment pipeline doesn’t drop events during token rotation.