SyncKit is a sync engine designed for local-first applications that enables real-time collaboration without vendor lock-in. Developers can implement features like rich text editing, live presence tracking, and automatic conflict resolution with just a few lines of code. The core setup involves initializing SyncKit and creating a document instance, which allows seamless updates and synchronization across different sessions and tabs. The engine supports popular frameworks like React, Vue, and Svelte, making it accessible to a wide range of developers. It offers features such as character-level sync, offline capabilities, and a robust undo/redo mechanism. The package is relatively lightweight, with the complete version being 154KB gzipped, while a "Lite" variant is available at 46KB for size-critical applications. SyncKit also includes performance optimizations, achieving local operations in under 1ms and sync latency below 100ms. In practice, developers can test SyncKit through a quick demonstration that showcases live collaboration. By opening two tabs and joining the same room, users can see changes reflected in real-time, along with cursor positions indicating where each person is typing. This functionality is powered by CRDTs (Conflict-free Replicated Data Types), which manage data consistency even when multiple users edit simultaneously. The system also emphasizes data sovereignty, being open-source and self-hostable, thus avoiding high subscription costs associated with proprietary solutions.