Error: 400 Bad Request
{"code": 400, "message": "Bad Request", "status": "Bad Request", "errors": ["Invalid subscription payload."]}
My Node.js script keeps failing on reconnect. I am using the standard genesys-cloud-node-sdk. When the socket drops, the client tries to resubscribe but gets a 400. Here is my config:
Why is the payload invalid on retry?
notifications:
endpoint: wss://api.mypurecloud.com/api/v2/notifications
retry:
maxAttempts: 5
delayMs: 2000
You should probably look at at how the SDK handles the subscription state during reconnection. The 400 error usually happens because you are sending a duplicate or stale subscription payload that the server rejects as invalid or already active. The genesys-cloud-node-sdk manages this, but if you are forcing a reconnect or handling it manually, you need to ensure the Notificator is fully reset before resubscribing.
Here is the pattern I use in my Lambda wrappers to handle this cleanly:
const { PureCloudPlatformClientV2 } = require('@genesyscloud/purecloud-platform-client-v2');
async function handleReconnect(platformClient) {
const notificationsApi = platformClient.NotificationsApi;
// 1. Ensure clean state
try {
await notificationsApi.close();
console.log('Closed existing notification connection');
} catch (e) {
// Ignore if already closed
}
// 2. Re-initialize if necessary (depends on your SDK version/config)
// In newer SDKs, you might just need to ensure the event emitter is clear
notificationsApi.removeAllListeners();
// 3. Resubscribe with valid payload
const subscription = {
name: "my-reconnected-sub",
eventTypes: ["routing.conversations"],
endpoint: "wss://api.mypurecloud.com/api/v2/notifications",
// Ensure scope matches your token
scope: "notification:write"
};
try {
const result = await notificationsApi.postNotificationSubscription(subscription);
console.log('Resubscribed successfully:', result.body);
} catch (err) {
console.error('Re-subscription failed:', err.body);
throw err;
}
}
Make sure your OAuth token is still valid. If the token expired during the disconnect, the 400 might actually be a masked 401/403 depending on how the gateway parses the header. Check the Authorization header before the POST. I usually refresh the token in my CDK-backed Lambda layer before triggering any notification API calls.
According to the docs, they say that the Notificator class is designed to be a singleton within a session, and manual re-instantiation often leads to state desynchronization.
I build Python wrappers daily, so I see this pattern often in Node.js too. The issue is not just the payload, but the internal subscription ID tracking. When the socket drops, the server side may still consider the subscription active for a few seconds. If you send the same subscriptionId or a malformed reset payload, you get 400.
You should not manually handle the WebSocket connection. Instead, rely on the SDK’s built-in retry logic, but ensure you are using the correct Notificator initialization. The suggestion above mentions resetting, but here is the concrete way to handle it in a wrapper to avoid the 400 loop.
First, ensure your Notificator is configured with proper backoff. The default might be too aggressive.
const { Notificator } = require('@genesyscloud/genesyscloud-node-sdk');
const notificator = new Notificator({
accessToken: 'your-access-token',
// Explicitly set retry policy to avoid hammering the API
retryPolicy: {
maxAttempts: 5,
delay: 1000, // Start with 1s
maxDelay: 10000 // Cap at 10s
}
});
// Correct way to subscribe
notificator.addSubscription({
"topics": ["routing.users.<userId>.events"],
"endpoint": "wss://api.mypurecloud.com/api/v2/notifications"
});
The key is addSubscription. Do not call subscribe directly on the WebSocket. If you are getting 400, check if topics is empty or malformed. Also, verify your OAuth token has notifications:read scope. If the token expires during a long-running script, the reconnect will fail with 401 or 400 if the new token is not injected before the retry.
In my Python client, I wrap this in a try/except block that catches ValidationError from the response payload. If you see 400, log the errors array from the response body. It usually tells you exactly which field is invalid.
Are you using a custom endpoint? If so, ensure the URL matches your region exactly. api.mypurecloud.com is global, but some older instances use api.us-east-1.mypurecloud.com. Mismatch causes 400.
If I recall correctly, the 400 error stems from stale subscription IDs persisting in the client state during rapid reconnects. In my Python analytics workflows, I avoid manual websocket management entirely. Instead, I let the PureCloudPlatformClientV2 SDK handle the Notificator lifecycle. The issue is likely that your Node SDK instance retains the old subscriptionId from the dropped connection. When it attempts to resubscribe with the same ID, the server rejects it as invalid because the server-side state hasn’t fully cleared or conflicts with the new attempt. You need to explicitly clear the subscription cache before re-initiating the connection.
Here is how I handle this in my Jupyter notebooks using the Python SDK, which follows the same underlying logic. You should apply this pattern to your Node SDK by calling the equivalent method to reset the notificator state before calling subscribe.
from platform_sdk_python import PureCloudPlatformClientV2, Notificator
# Initialize client
client = PureCloudPlatformClientV2()
client.set_access_token(access_token)
# Create notificator instance
notificator = Notificator(client)
def on_disconnect():
# CRITICAL: Clear existing subscriptions to prevent 400 Bad Request on reconnect
notificator.clear_subscriptions()
print("Subscriptions cleared. Attempting to resubscribe...")
# Resubscribe logic here
notificator.subscribe(...)
notificator.on_disconnect = on_disconnect
notificator.start()
In Node.js, ensure you call notificator.stop() or the equivalent reset method before calling start() again. The genesys-cloud-node-sdk does not automatically purge stale subscription contexts. If you force a reconnect without clearing the internal subscriptionId map, the payload sent to wss://api.mypurecloud.com/api/v2/notifications contains metadata that conflicts with the server’s expectation of a fresh session. This is a common pitfall when handling transient network errors in long-running scripts. Always verify the subscriptionId in the payload is unique or null when initiating a new subscription cycle.
It depends, but generally you should not rely on the SDK’s implicit reconnect logic for Pact-consumer testing. The 400 error occurs because the server rejects duplicate subscription payloads before the previous session fully expires.
Force a clean state before re-subscribing. In Node.js, explicitly unsubscribe all active handlers before restarting the Notificator:
const { PureCloudPlatformClientV2 } = require('@genesyscloud/genesyscloud-node-sdk');
const platformClient = PureCloudPlatformClientV2;
const notificator = platformClient.Notificator;
// Cancel all existing subscriptions to clear server-side state
await notificator.unsubscribeAll();
// Re-initialize with fresh config
notificator.setConfig({
endpoint: 'wss://api.mypurecloud.com/api/v2/notifications',
retry: { maxAttempts: 5 }
});
// Resubscribe
await notificator.subscribe('/v2/notifications/conversations', handler);
This aligns with consumer-driven contract best practices: ensure the provider state is deterministic.