AgIoT is a modular IoT platform developed under the SmartFarming and Water4Ever projects, focused on optimizing irrigation in precision agriculture. Designed for integration with both conventional and smart farming machinery, it supports real-time monitoring of soil moisture, plant health, and environmental conditions through embedded sensors. The system enables variable-rate irrigation, NPK management, and in-field automation, using data from sensors and GNSS technologies like Galileo and EGNOS for spatial accuracy. AgIoT is built to be interoperable with standards such as ISOBUS and FIWARE, facilitating scalable, sustainable water management across diverse farming contexts.