Architect Data Action to Lambda returning 500 Internal Server Error on Invoke

Trying to call an AWS Lambda function from Genesys Architect using a Data Action. The flow is simple: route the call, hit the data action, get a response. It works locally with the AWS CLI but fails in the flow with a generic 500 Internal Server Error. No useful logs in the Architect trace. Suspect IAM role permissions or the payload structure. The Lambda expects a JSON body with a specific schema. Here’s the Data Action config:

{
 "type": "invoke",
 "url": "https://lambda.eu-west-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:eu-west-1:123456789:function:my-func/invocations",
 "method": "POST",
 "body": "{{payload}}"
}

The IAM role attached to the Lambda has basic permissions. The endpoint is public-facing via API Gateway, but I’m trying to call the Lambda directly for lower latency. The request times out after 30 seconds.

  • Region: eu-west-1
  • Lambda Runtime: Node.js 18
  • Timeout: 30s
  • Payload: JSON string
  • Error: 500 Internal Server Error

Anyone have a working example of this setup? The docs are vague on the exact IAM policy needed for direct invocation from Genesys.