Yeelight 3rd-party control protocol is a feature designed for developers and fans of IoT. All Yeelight WiFi products that are currently on market (Yeelight LED bulb (White), Yeelight LED bulb (Color)) as well as upcoming WiFi light products will support this protocol. Based on this protocol, users can develop their own applications and programs to discover and control Yeelight WiFi devices by using their favorite platform or language. This control protocol uses a SSDP-like discovering mechanism and JSON encoded controlling command, developers can discover and control their devices dynamically under the same LAN. Attention must be payed to following security issue: all the discover and control messages defined in this protocol are not encrypted, which means Yeelight devices’ security is guaranteed by the router’s security level, therefore user must be responsible for their devices’s security when using this control protocol.