walcast

Postgres change data capture for Node: a hand-written pgoutput decoder speaking the streaming replication protocol, exposed as an async iterator with explicit LSN acknowledgment — plus a plugin engine and daemon when you want delivery managed for you.

The core transports nothing. Every event transport is a separately installed @walcast/* plugin; library mode needs none of them.

npm install walcast

import { Walcast } from 'walcast'

const tr = new Walcast({ connection: process.env.DATABASE_URL! })
await tr.setup()

for await (const event of tr.changes()) {
  await handle(event) // at-least-once; event.id is stable across redelivery
  tr.ack(event) // the replication slot only advances past acked work
}

Daemon mode (npx walcast serve) runs sink plugins with ordering, batching, retries, backpressure, and per-sink LSN checkpoints, and serves a dashboard at /ui:

npm install @walcast/sink-webhook
npx walcast serve

Docs: https://walcast.mmadan.in · Repo: https://github.com/ManasMadan/walcast

License

MIT