@pumped-fn/lite-extension-sync-nats

NATS JetStream KV transport for @pumped-fn/lite-extension-sync.

import { Kvm } from "@nats-io/kv"
import { connect } from "@nats-io/transport-node"
import { createScope } from "@pumped-fn/lite"
import { sync } from "@pumped-fn/lite-extension-sync"
import { nats } from "@pumped-fn/lite-extension-sync-nats"

const nc = await connect({ servers: "127.0.0.1:4222" })
const kv = await new Kvm(nc).create("drafts", { history: 5 })

const scope = createScope({
  extensions: [sync.extension()],
  tags: sync.runtime({
    peer: "worker-1",
    transport: nats.kv(kv),
  }),
})

The adapter stores strict sync messages as UTF-8 JSON bytes in JetStream KV, uses watch updates for live delivery, and returns the backend KV revision as the sync write acknowledgement. JetStream stale-revision responses return sync write conflicts, so backend CAS conflicts flow through the same sync conflict path as watched remote records. Watch failures resubscribe from the last delivered KV revision by default. Use nats.kv(kv, { prefix, onError, retry }) to customize the KV subject prefix, receive watch-loop failures from the adapter boundary with retry metadata, or disable adapter-level retry with retry: false.

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