EventBridge Rule Pattern for Genesys Cloud Webhook Authentication Failures

NICE CXone API & Integrations
1

Why does this config cause a 403 Forbidden when the EventBridge rule triggers my Lambda consumer? I’m setting up a direct integration to receive v2.routing.user.wrapup events from Genesys Cloud into an AWS EventBridge bus. The GC webhook endpoint is configured with the correct EventBridge ARN, but the Lambda function consistently fails the initial handshake validation.

Here is the EventBridge rule pattern I’m using:

{
 "source": ["genesys.cloud"],
 "detail-type": ["Routing User Wrapup"]
}

The Lambda logs show the event payload arrives, but the detail object is empty. I’ve verified the IAM role has events:PutEvents permissions. Is there a specific header or payload structure GC sends that EventBridge strips before invoking the target? I need to parse the event_id from the detail, but it’s missing entirely.

2

Check your Invoke-RestMethod call for the webhook config. You likely need Headers = @{ Authorization = "Bearer $token" } and ContentType = "application/json" to pass the 403. Genesys Cloud rejects unauthenticated PUT requests to /api/v2/webhooks.

3

If I remember correctly, EventBridge validates the source IP against Genesys Cloud’s known ranges, but the 403 here likely stems from missing x-amzn-trace-id header propagation in the webhook payload. Ensure your Lambda parses the raw event body correctly.

{
 "default": "allow",
 "conditions": {
 "source": ["genesys.cloud"]
 }
}

Verify the webhook endpoint isn’t rejecting the initial HTTPS handshake due to TLS version mismatch.

4

This issue stems from the webhook endpoint expecting a specific HMAC signature that EventBridge does not natively generate or forward.

The standard AWS Signature V4 is not compatible with Genesys Cloud’s webhook authentication requirements.

You need an intermediary Lambda to validate the x-gc-webhook-signature header before forwarding to EventBridge.

5

The problem is that Genesys Cloud requires HMAC validation via the x-gc-webhook-signature header, which EventBridge strips during ingestion. You must route through a validation Lambda first using hmac.new(key, payload, hashlib.sha256).hexdigest() to verify the signature before forwarding to the bus.