Show HN: SyncKit – Offline-first sync engine (Rust/WASM and TypeScript)

Summary

SyncKit 🎯 What is SyncKit? SyncKit is a production-ready sync engine that makes building local-first applications trivial. "Add sync.document() to your app, get real-time sync automatically." The problem: Building sync from scratch takes months. Existing solutions are complex (Yjs), expensive (Firebase), or don't work offline (Supabase). The solution: SyncKit gives you production-ready sync in 3 lines of code. const sync = new SyncKit ( ) await sync . init ( ) const doc = sync . document < Todo > ( 'todo-123' ) await doc . update ( { completed : true } ) // ✨ Works offline, syncs automatically, resolves conflicts 🎬 See It In Action Real-time collaboration with offline resilience: Watch tasks sync instantly across tabs—even while offline. The example app demonstrates SyncKit's offline-first capabilities combined with smart browser storage to create a seamless collaborative experience. ✨ Why SyncKit? 🚀 Works When Internet Doesn't True offline-first architecture—not just caching. Your app works perfectly on planes, trains, tunnels, and coffee shops with spotty WiFi. 📦 Enterprise Features, Startup Bundle ~59 KB gzipped (10KB SDK + 49KB WASM) - Complete WASM-based sync engine with TypeScript SDK. Current features (v0.1.0): ✅ Offline-first sync (LWW) ✅ Real-time collaboration ✅ Network protocol support ✅ IndexedDB persistence ✅ Cross-tab sync (see example) Coming in v0.2.0: 🚧 Text CRDTs (character-level editing) 🚧 Counters, Sets (distributed data structures) Size-critical apps? Use Lite variant (~45 KB gzipped: 1.5KB SDK + 44KB WASM, local-only) Competitive bundle size: Larger than Yjs (~19KB pure JS), smaller than Automerge (~60-78KB). 🔓 Your Data, Your Rules Open source and self-hostable. No vendor lock-in, no surprise $2,000/month bills, complete data sovereignty. ⚡ Fast by Design <1ms local operations (~5-20μs single field update) <100ms sync latency (10-50ms p95) ~59KB bundle (10KB SDK + 49KB WASM), ~45KB lite option Sub-200KB total with React 🛡️ Data Integrity Guara...