Lambda Data Action returning 502 despite valid IAM role and working test invocation

Architect & Flows
1

We’re wiring up a Genesys Cloud Data Action to trigger an AWS Lambda function. The goal is to enrich the session with user tenure data. The Lambda works perfectly when invoked via the AWS Console or CLI. It also works when we hit it directly via API Gateway with a POST request containing the same JSON payload.

The issue surfaces only when Architect calls it. We get a 502 Bad Gateway from the Data Action response. The Lambda logs show no invocations, which tells me Genesys isn’t even reaching the function handler. It’s likely an IAM or endpoint configuration glitch.

Here’s the Data Action JSON configuration:

{
 "name": "enrich_user_tenure",
 "type": "http",
 "method": "POST",
 "url": "https://lambda.us-east-1.amazonaws.com/2015-03-31/function/arn:aws:lambda:us-east-1:123456789012:function:tenure-check",
 "headers": {
 "Content-Type": "application/json",
 "X-Amz-Invocation-Type": "RequestResponse"
 },
 "body": "{{$.input.json}}"
}

The IAM role attached to the Genesys Cloud integration user has lambda:InvokeFunction permissions on that specific ARN. We’ve double-checked the trust policy on the Lambda role. It accepts lambda.amazonaws.com.

Are we missing a specific header for the AWS Signature? Or does the Lambda endpoint require a different auth mechanism than standard IAM roles when called from external HTTP clients like Genesys? We’ve tried adding X-Amz-Target but that didn’t help. The error response body is just "Error: Bad Gateway" with no stack trace.

2

check your architect data action timeout settings. the default is often too low for cold starts.

i’ve seen this exact 502 when the lambda takes longer than the configured timeout to return. architect gives up and marks it failed. the lambda logs might show nothing if the request never actually reached the handler due to gateway rejection before invocation.

try bumping the timeout in the data action config to 5000ms or higher. also verify the api gateway integration timeout is set high enough.

{
 "name": "EnrichTenure",
 "type": "REST",
 "endpoint": "https://your-api-gateway-id.execute-api.us-east-1.amazonaws.com/d/enrich",
 "method": "POST",
 "timeout": 5000,
 "headers": {
 "Content-Type": "application/json"
 }
}

if that doesn’t fix it, check the api gateway logs. sometimes the 502 comes from the gateway rejecting the payload format. architect sends specific fields. make sure your lambda can handle the wrapper object it receives.