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Security & Sync

Local-First Sync

Opt into local-first replication with one line — optimistic hooks, a changefeed, and a transaction queue.

A resource opts into local-first replication with sync: { mode: "local", … } in its options. The client runtime — an IndexedDB store, an optimistic transaction queue, and a long-poll changefeed — is generated from the x-rastack-sync OpenAPI extension.

resources/chat.ts

ts · copy

export

const

Message

resource

(

"chat"

"message"

{

room

ref

(()

Room

body

string

(),

{

sync

{

mode

"local"

});

Optimistic by default

Synced hooks are async and optimistic by default: a mutation applies to the local store immediately and reconciles with the server in the background. Individual operations can opt into blocking ("sync") semantics where correctness demands it — for example, a password change.

The client runtime

Piece

Role

tools/sync/ store

an IndexedDB-backed local copy of each synced table

transaction queue

holds optimistic mutations until the server confirms them

long-poll changefeed

streams server changes back into the local store

! Warning

The client runtime ships today. The server endpoints (/api/sync/v1/{bootstrap,changes}) are being ported to the Rust API; rastack compile already emits x-rastack-sync so the client hooks generate now.

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