Need some help troubleshooting…
I am building a self-hosted automation pipeline to process real-time Genesys Cloud interaction events via Webhooks. The target consumer is an AWS Lambda function written in Node.js 18.x. The goal is to ingest interaction.analyzed events and push them to an SQS queue for downstream processing in n8n.
The issue occurs during the initial deserialization of the request body. The Lambda function is returning a 502 Bad Gateway error, and the CloudWatch logs show a TypeError: Cannot read properties of undefined (reading 'id'). This suggests the payload structure expected by my code does not match what Genesys Cloud is sending.
Here is the relevant snippet from my Lambda handler:
exports.handler = async (event) => {
const payload = JSON.parse(event.body);
console.log('Received payload:', JSON.stringify(payload, null, 2));
// Failing here
const interactionId = payload.interaction.id;
return {
statusCode: 200,
body: JSON.stringify({ message: 'Processed', id: interactionId })
};
};
The webhook subscription is configured to send payloads in the default format. I have verified the endpoint is reachable via curl. The error only manifests when Genesys Cloud triggers the webhook.
- I have confirmed the Lambda execution role has necessary permissions and the API Gateway integration is set to
Lambda Proxy Integration.
- I have logged the raw
event.body string to CloudWatch, and it appears to be a valid JSON string, but the structure seems nested differently than I anticipated.
What is the correct structure of a Genesys Cloud webhook payload when sent to an API Gateway? Is there a specific wrapper object I am missing? How should I safely extract the interaction.id field?
TL;DR: Verify JSON parsing and scope.
The problem here is likely missing application/json header handling in the Lambda trigger or incorrect scope configuration on the webhook. Use const body = JSON.parse(event.body); and ensure the OAuth client has analytics:report:read for interaction events.
If I remember correctly, analytics:report:read is for aggregated reports, not real-time webhook events. You need analytics:interaction:read or analytics:interaction:write depending on the event type, otherwise the payload might be empty or rejected.
Check the OAuth scopes assigned to the client creating the webhook. A 502 often masks a 403 at the API layer if the token lacks the specific interaction scope required to deserialize the event data securely.
Have you tried verifying the payload structure in your local mock server before it hits the Lambda handler? The suggestion above about analytics:interaction:read is correct for the API scope, but a 502 usually indicates a runtime crash in Node.js, not an authentication failure.
In my Docker Compose integration tests, I often see this happen when the webhook payload includes nested objects that are not strictly valid JSON or contain binary data. Ensure your local mock server is sending Content-Type: application/json. If the body is null or undefined, JSON.parse will throw an unhandled exception, causing the Lambda to crash before returning a proper status code.
You should wrap the parsing logic in a try-catch block to log the raw event body. This helps distinguish between a malformed payload and a missing scope. Use this pattern to safely deserialize the incoming data and inspect the error stack trace in CloudWatch.
let body;
try {
body = event.body ? JSON.parse(event.body) : {};
} catch (e) {
console.error('Parse error:', e.message);
return { statusCode: 400, body: 'Invalid JSON' };
}
You need to handle the base64 decoding explicitly before parsing the JSON payload. The suggestion above regarding the analytics:interaction:read scope is correct for the API layer, but a 502 error in Node.js Lambda usually indicates a runtime exception during deserialization, not a scope failure.
Genesys Cloud webhooks send the body as a base64-encoded string. If you pass event.body directly to JSON.parse, it fails because the input is not valid JSON. I encountered similar confusion while building my .NET reporting dashboard, where the SDK handled this automatically, but raw Lambda handlers do not.
Here is the corrected handler logic:
exports.handler = async (event) => {
try {
// Decode base64 string to UTF-8 string first
const decodedBody = Buffer.from(event.body, 'base64').toString('utf-8');
const payload = JSON.parse(decodedBody);
console.log("Parsed Interaction:", payload);
return { statusCode: 200, body: "Success" };
} catch (e) {
console.error("Deserialization failed:", e.message);
return { statusCode: 500, body: e.message };
}
};
Verify the event.body is indeed base64. If it is not, your API Gateway integration may be configured to pass through raw JSON, in which case you can skip the Buffer step. Check your API Gateway settings for “Binary Media Types” as well.