@pumped-fn/lite-extension-sync

Strict replicated state for Lite scopes.

Migration to 1.0.0

Install 1.0 with Lite 6:

npm install @pumped-fn/lite@^6.0.0 @pumped-fn/lite-extension-sync@^1.0.0

Usage

import { createScope } from "@pumped-fn/lite"
import { sync } from "@pumped-fn/lite-extension-sync"

const draft = sync({
  id: "draft",
  factory: () => ({ title: "", body: "" }),
})

const wire = sync.memory()

const left = createScope({
  extensions: [sync.extension()],
  tags: sync.runtime({ peer: "left", transport: wire }),
})

const right = createScope({
  extensions: [sync.extension()],
  tags: sync.runtime({ peer: "right", transport: wire }),
})

sync(...) returns an atom-like value. Plain JSON-safe state is inferred. Non-JSON state must use a codec, and every inbound value is decoded before it can be applied.

Semantics

The core extension is transport-driven: a local controller change is encoded, written as a per-key Sync.Message, and remote peers apply subscribed messages from other peers; without a conflict policy, an inbound value replaces the local value. Conflict handling is opt-in per atom: sync.revision(...) accepts only higher app-level revisions and reports equal-version conflicts, while sync.lww(...) keeps the value with the greater-or-equal app-level timestamp/version. The NATS KV transport stores one KV entry per sync key with backend revision acks, maps stale revision writes to WriteConflict, and resumes watches from the last delivered KV revision; it does not introduce a leader or cross-key ordering.

Part of pumped-fn — start with the docs or the mental model.