title: AWS Cognito for API token authentication
body: <p>I am building an HTTP API in java that uses AWS cognito, and developer authenticated identities to provide tokens to secure the API. I have configured the login system to issue a cognito token when a user logs in and the cognito identity pool contains each user and a developer identity associated with my backend, but I am having a very difficult time finding a straightforward way to retrieve a users specific developer identifier from the cognito token. I have attempted to use the <code>AssumeRoleWithWebIdentityResult</code> API call, but have been unable to find documentation about it for determining the developer identifier, only examples for obtaining temporary AWS credentials.</p>