cognito authentication from nodeJS

simple-cognito-auth.js

var AWS = require('aws-sdk');
var AWSCognito = require('amazon-cognito-identity-js');
var util = require('util');

var params = {
    Username: '',
    Password: '',
    UserPoolId: 'us-west-2_aLI134pRo',
    ClientId: '3jmku5aeaqe6pdkqa5q18trjk5',
    IdentityPoolId: 'us-west-2:93be5994-d1aa-4e3a-b088-3ed28fa4b068',
    AWSRegion: 'us-west-2'
}

AWS.config.update({region: params.AWSRegion});

var authenticationData = {
    Username : params.Username,
    Password : params.Password
};
var authenticationDetails = new AWSCognito.AuthenticationDetails(authenticationData);

var poolData = {
    UserPoolId : params.UserPoolId,
    ClientId : params.ClientId
};
var userPool = new AWSCognito.CognitoUserPool(poolData);


var userData = {
    Username : params.Username,
    Pool : userPool
};
var cognitoUser = new AWSCognito.CognitoUser(userData);

cognitoUser.authenticateUser(authenticationDetails, {

    onSuccess: function (result) {
    	console.log("User Authenticated !");
        cognitoUserPoolLoginProvider = 'cognito-idp.' + params.AWSRegion +  '.amazonaws.com/' + params.UserPoolId;
        var logins = {};
        logins[cognitoUserPoolLoginProvider] = result.getIdToken().getJwtToken();

        AWS.config.credentials = new AWS.CognitoIdentityCredentials({
            IdentityPoolId : params.IdentityPoolId, // your identity pool id here
            Logins : logins
        });

        AWS.config.credentials.get(function(err) {
            if (err) {
                callback(err, null);
            } else {
                var creds = {
                    AccessKeyId: AWS.config.credentials.accessKeyId,
                    SecretAccessKey: AWS.config.credentials.secretAccessKey,
                    SessionToken: AWS.config.credentials.sessionToken,
                }
            }

			var cognitoidentityserviceprovider = new AWS.CognitoIdentityServiceProvider();

			

			cognitoidentityserviceprovider.listUsers({UserPoolId: params.UserPoolId}, function(err, data) {
			  if (err) {
			  	console.error("Unable to read item. Error JSON:", JSON.stringify(err, null, 2));
			  } else {
			    console.log("GetItem succeeded:", JSON.stringify(data, null, 2));
			  }
			});


			var dynamodb = new AWS.DynamoDB();
			var docClient = new AWS.DynamoDB.DocumentClient();

			var readParams = {
			    TableName: "Movies",
			    Key:{
			        "year": 2015,
			        "title": "The Big New Movie"
			    }
			};

			docClient.get(readParams, function(err, data) {
			    if (err) {
					console.error("Unable to read item. Error JSON:", JSON.stringify(err, null, 2));
			    } else {
			        console.log("GetItem succeeded:", JSON.stringify(data, null, 2));
			    }
			});
            
        });
    },

    onFailure: function(err) {

		console.log("Error authenticating ! Trying an API call anyway.... (will fail)");

		var cognitoidentityserviceprovider = new AWS.CognitoIdentityServiceProvider();

		cognitoidentityserviceprovider.listUsers({UserPoolId: params.UserPoolId}, function(err, data) {
		  if (err) {
		  	console.log(err, err.stack);
		  } else {
		  	console.log(data);
		  }
		});

    },

});        

Thanks for this @ddewaele, it was useful to see things laid out this way.