Most apps treat the server as truth. Peer-to-peer flips that: state starts local, users carry the data, and shared truth emerges without routing every interaction through a central backend.
Outline:
- The normal React/backend model
- Server/database as the source of truth
- The local-first flip
- Local state becomes the primary user experience
- From local-first to peer-to-peer
- Users replicate state directly instead of only syncing through APIs
- Using a chat app as the running example, with quick comparisons to docs, boards, and media sharing
- How shared truth emerges
- User actions as signed operations in append-only logs
- Deterministic app rules decide which operations are valid
- Peers agree on ordering and can independently verify the resulting state
- What this means for React developers
- UI becomes a view over local replicated state
- Reality check and takeaways
- P2P does not remove backend complexity; it turns it into protocol and state design
- Tradeoffs include availability, permissions, conflict handling, and migrations
- These are normal apps with a different source of truth — and they're possible now
Will keep it high-level, practical, and example-driven. Including some lessons from building real peer-to-peer apps like Keet.
JSNation 2026
