How do I access the group for a Cognito User account?

Question

In AWS Cognito, you can add a user to a group (after first creating a group). A user may belong to one or more groups.

With using the JavaScript SDK (https://github

Answer 1

I originally expected the Cognito JavaScript API to provide a simple property or method to return the list of groups, but instead I concluded that it was buried within a token, and thus had to learn about jwt. Once the Cognito User is established and the session is retrieved, the array of groups is available within the IdToken.

var jwtDecode = require('jwt-decode');
var AmazonCognitoIdentity = require('amazon-cognito-identity-js');
var CognitoUserPool = AmazonCognitoIdentity.CognitoUserPool;
var CognitoUser = AmazonCognitoIdentity.CognitoUser;

var userPool = new CognitoUserPool({UserPoolId:'', ClientId:''");
...
app.get('/app', function(req, res){
    var cognitoUser = userPool.getCurrentUser();
    if(cognitoUser != null){
        cognitoUser.getSession(function(err, session) {
            if (err) {
                console.error(err);
                return;
            }
            console.log('session validity: ' + session.isValid());

            var sessionIdInfo = jwtDecode(session.getIdToken().jwtToken);
            console.log(sessionIdInfo['cognito:groups']);
        });
    }
});