Datastar is a lightweight, reactive frontend library that enables building dynamic web applications using declarative HTML attributes and server-sent events (SSE). Its core architecture is a plugin-based engine that registers attribute plugins, action plugins, and watcher plugins. The system includes a fine-grained reactive signal system (signals, computed, effects) with batched updates and deep proxy support, a DOM morphing algorithm for efficient patching, and an SSE client with retry logic. The library also provides built-in plugins for event handling, two-way binding, conditional rendering, form support, and more. The repository includes a comprehensive SDK test suite (in Go) for validating backend implementations, as well as IDE plugins for VS Code and IntelliJ. Although the official SDKs for multiple languages have moved to separate repositories, the test suite and architecture documentation remain here. The codebase is well-structured with clear separation of concerns, but contains some unresolved merge conflicts and no visible test coverage for the core library, indicating moderate technical drift.