How to get the Cognito Identity id in AWS Lambda

Question

How can I get the identity id of the user (logged in by AWS Cognito) that invoked an AWS Lambda function? Do I have to use the SDK on the Lambda function to get the identity id?

Answer 1

You can let Cognito/IAM handle the identity validation part, and you can assume that if a user is able to trigger a Lambda function successfully, that will mean he is allowed to do that. In this case, you can manage per-user validation, take a look at whitelisting.