Internet of Things (IoT) is a concept that was coined to utilize internet connectivity as a medium of communication of objects continuously. Basically, all sensor data or inputted by humans are sent and stored in a database server for further use. Several devices can be used as a client/server such as ESP8266 that communicates with certain topologies and certain protocols (UDP, TCP, MQTT, HTTP, etc.) for certain purposes. The application of the IoT system is to support automation systems in Smart City, Smart Home, Multi-Robot, agriculture, etc.