Comprehensive HVAC Platform with API-First Architecture

I need a full-featured HVAC application that runs natively on both Windows and macOS and exchanges real-time data with our existing Building Management System (BMS). At this stage, I am keeping the functional... (Budget: $2000 - $7000 USD, Jobs: API, Data Management, Desktop Application, HVAC, Software Architecture, Software Development, UI / User Interface, User Experience Research)