Mongoose OS is integrated natively with AWS IoT cloud.
AWS IoT uses MQTT for communication.
Check the c_mqtt example on GitHub, build and flash it.
The single command “aws-iot-setup” performs the certificate management and onboard your device on AWS IoT cloud.
Use mos aws-iot-setup command to register your device with the AWS IoT: mos aws-iot-setup
Cesanta's Mongoose OS featured at AWS reInvent 2016 IoT Build, Test, and Securely Scale talk