lambda.js

// Dependencies
const AWS = require('aws-sdk');
const sns = new AWS.SNS();
const moment = require('moment');

exports.handler = (event, context, callback) => {
	// Parse incoming event payload
	const payload = JSON.parse(event.Records[0].body)[0].new[0];

	// This should be your database
	const cache = {
		actors: ['Nick'],
		verbs: {
			tweet: 'tweeted'
		}
	};

	const actor = cache.actors[0]; // Hardcoding user, should be a database lookup
	const verb = cache.verbs[payload.verb]; // Hardcoding verb (should be a ternary or if/else statement)
	const tweet = payload.tweet; // The example always contains a tweet
	const time = moment(payload.time).format('MMMM Do YYYY [at] h:mm:ss A'); // Time is ISO-8601 formatted

	// Build params
	const params = {
		Message: `${actor} ${verb} "${tweet}" on ${time}`, // SMS message that gets sent to the subscriber (AKA your device)
		TopicArn: 'YOUR_AWS_SNS_TOPIC_ARN' // Only works on localhost (hardcode value for AWS deployments)
	};

	// Send a SMS via AWS SNS
	sns.publish(params, (err, data) => {
		if (err) {
			return callback(err.stack);
		} else {
			callback(null, data);
		}
	});
};