Hey folks,
Running into a frustrating IAM issue with a Genesys Cloud Architect Data Action calling an AWS Lambda. The setup is straightforward. We’ve got a Data Action configured to call a Lambda function via HTTPS. The endpoint is set up as a proxy integration. The problem is we’re getting a 403 Forbidden error back from AWS. Specifically, the error body says InvalidSignature. This usually means the signature calculation is off, but we’re using the standard HTTPS method in Architect.
Here’s the IAM policy attached to the Lambda role. It looks right to me. It allows lambda:InvokeFunction on the specific ARN.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "lambda:InvokeFunction",
"Resource": "arn:aws:lambda:us-west-2:123456789012:function:my-contact-handler"
}
]
}
The Lambda function itself works fine. I tested it via the AWS Console and Postman with a signed request. It returns a 200 OK. So the code is good. The issue is strictly the invocation from Genesys.
I’ve checked the region. It’s us-west-2. The ARN matches. I even tried adding a * resource just to rule out ARN typos. Still getting 403.
Is there a specific requirement for the IAM role when invoked via Genesys Cloud? I know Genesys uses AWS SigV4 for some integrations. But for a simple HTTPS POST to a Lambda, shouldn’t the Lambda just accept it if the role allows it? Or is the InvalidSignature coming from the Lambda function’s internal validation of the incoming request headers?
The Data Action configuration is basic. Method: POST. Payload: JSON. Headers: Content-Type application/json. No custom headers for auth.
Any ideas on what’s causing the signature mismatch? We’re blocked on this deployment. Appreciate any help.