Testing IoT devices can be quite challenging, primarily due to the need for real hardware to effectively simulate how these devices interact in live environments, such as Smart Home. Unlike software, which can often be tested in virtual settings, IoT devices require physical setups to account for network conditions, interoperability, and real-world response times. This reliance on physical devices, raising costs and reducing scalability, makes it difficult to test complex or large-scale IoT networks comprehensively. This thesis aims to solve this problem, by designing and developing a simulator of Commercial-Off-The-Shelf smart devices, in this case Shelly devices, replicating their functionalities and their interactions among one another and within the Smartotum ecosystem and the Home Assistant platform.