Jsontology is an open-source Golang library built to match JSON data against user-defined rules in real time. Its objective was to create a lightweight, extensible rule engine capable of handling both simple conditions and complex logical structures. The library supports advanced features such as event aggregation, where actions are triggered only after repeated occurrences, and propositional logic (AND/OR) for combining multiple rules. By emphasizing Test-Driven Development (TDD) and planning for multi-language support (Python and JavaScript in progress), Jsontology provides developers with a dependable and versatile tool. It brings value by enabling advanced filtering, decision-making, and event-driven processing in systems that rely heavily on streaming JSON data.