Multi-device sync

Multi-device sync is scoped bucket convergence — not full-database replication.

Shared tenancy model

1. Authenticate each device with the same user (or shared shop membership)
2. Resolve buckets from sync-rule parameters (membership table or JWT claims)
3. Each device calls bucketsForSyncRule with the buckets it cares about
4. All devices pull/push against the same server Postgres

Web + mobile

Layer	Web	React Native
Persistence	waSqlitePersistence	opSqlitePersistence
HTTP	fetch	installNitroFetch / createNizhalNitroClient
Realtime	PartySocket default	nitroWebSocketSource
Online detection	navigator.onLine	reactNativeOnlineDetector (NetInfo)

Use the same syncRules and mutators on server; generated contract types on both clients.

Convergence expectations

• Local write < 50ms with network down (TanStack optimistic path)
• After reconnect, remote device sees changes in < 5s with realtime (ping → pull)
• Without realtime, pull.intervalMs or manual echo.pull() still converges

Client ID reconciliation

When the server assigns a different PK than the client’s optimistic ID, push ack returns the mapping. Collections rebase local rows via TanStack DB.

Testing multi-device

• apps/credit-ledger/examples/multi-device-host.ts — scripted two-client check
• apps/emulation chaos harness — N clients with partition/restart injectors
• apps/op-sqlite-probe — real device persistence smoke

Revocation

Removing a device user’s membership must shrink their buckets. Verify pull returns removedBuckets and local purge — not just 403 on push.