A new AWS IoT Device SDK is now available. It is a complete rework, built to improve reliability, performance, and security. We invite your feedback! The aws-iot-device-sdk.js package allows developers to write JavaScript applications that access the AWS IoT Platform via MQTT or MQTT over the Secure WebSocket Protocol. It can be used in Node.js environments as well as in-browser applications. This package is built on top of mqtt.js and provides three classes: 'device', 'thingShadow' and 'jobs'. The 'device' class wraps mqtt.js to provide a secure connection to the AWS IoT platform and expose the mqtt.js interfaces upward. It provides features to simplify the handling of intermittent connections, including progressive backoff retries, automatic re-subscription upon connection and queued offline publishing with a configurable drain rate. Beginning with Release v2.2.0 of the SDK, AWS collects usage metrics indicating which language and version of the SDK is being used.