3scale_auth.js

var threescale = require('3scale');
var Client = threescale.Client;
client = new Client("YOUR_PROVIDER_KEY");

var authenticate = function(user_key,callback){
  client.authrep_with_user_key({"user_key": user_key, "usage": { "hits": 1 } }, function(resp){
    if(resp.is_success()){
			callback(null,resp.is_success());
		}else{
			callback("403, unauthorized");
		}
  });
};

exports.handler = function(event, context) {
  if(event.user_key){
    authenticate(event.user_key, function(err,res){
    if(err){
      context.fail(err);
    }else{
      context.succeed({"message":"hello world"});
    }
  });
  }else{
   context.fail("user_key missing")
  }
}

3scale_lambda_endpoint.js

var aws = require('aws-sdk');
var http = require('http');
var lambda = new aws.Lambda({
    region: 'us-west-2'
});

exports.handler = function(event, context) {
    console.log('Received event:', JSON.stringify(event, null, 2));
    var backend = "http://api-sentiment.3scale.net/v1"
    lambda.invoke({
      FunctionName: '3scale_auth',
      Payload: JSON.stringify(event, null, 2)
    }, function(error, data) {
    if (error) {
        console.log('error',error)
        context.done('error', error);
    }
    if(data.Payload){
        var d = JSON.parse(data.Payload)
        if(d.errorMessage){
            context.fail(d.errorMessage)
        }else{ //3scale auth passed
            // Endpoint LOGIC
            var url = backend + event.resourcePath
            if(event.word){
                url = url.replace("{word}", event.word);
                console.log(url)
            }else if (event.sentence){
                url = url.replace("{sentence}", event.sentence);
            }
            http.get(url, function(res) { //call backend endpoint
                var body = '';
                res.on('data',function(chunk){
                 body += chunk;
                });
                
                res.on('end',function(){
                 context.succeed(JSON.parse(body))
                });
                
            }).on('error', function(e) {
                console.log("Got error: " + e.message);
                context.fail(e)
             })
        }
    }
    });
};

lambda_redirect.js

var aws = require('aws-sdk');
var http = require('http');
var lambda = new aws.Lambda({
    region: 'us-west-2'
});

exports.handler = function(event, context) {
    console.log('Received event:', JSON.stringify(event, null, 2));
    var backend = "YOUR_BACKEND_URL";
    lambda.invoke({
      FunctionName: '3scale_auth',
      Payload: JSON.stringify(event, null, 2)
    }, function(error, data) {
    if (error) {
        console.log('error',error)
        context.done('error', error);
    }
    if(data.Payload){
        var d = JSON.parse(data.Payload)
        if(d.errorMessage){
            context.fail(d.errorMessage)
        }else{ //3scale auth passed
            // Endpoint LOGIC
            var url = backend + event.resourcePath
            http.get(url, function(res) { //call backend endpoint
                var body = '';
                res.on('data',function(chunk){
                 body += chunk;
                });
                
                res.on('end',function(){
                 context.succeed(JSON.parse(body))
                });
                
            }).on('error', function(e) {
                console.log("Got error: " + e.message);
                context.fail(e)
             })
        }
    }
    });
};

mapping_template.json

{
  "user_key":"$input.params('user_key')",
  "body" : "$input.json('$')",
  "resourcePath":"$context.resourcePath"
}