@xjonathanlei/bellows

TypeScript port of bellows, a durable task processing framework.

What it provides

• task definitions with serializable payloads
• a worker/dispatcher runtime
• backends for:
  • in-memory
  • SQLite
  • Postgres

Quick example

import { InMemoryBackend } from "@xjonathanlei/bellows/backends/in-memory";
import {
  WorkerDispatcher,
  definePublishTask,
  type WorkerFactory,
} from "@xjonathanlei/bellows";

const echoTask = definePublishTask<{ name: string }>("echo");
const backend = new InMemoryBackend();

const factory: WorkerFactory<typeof echoTask> = {
  task: echoTask,
  build() {
    return {
      async process(taskId, payload) {
        console.log(taskId, payload.name);
      },
    };
  },
};

const dispatcher = new WorkerDispatcher(backend, factory);
const handle = await dispatcher.launch();

await backend.publish(echoTask, { name: "Alice" });
await handle.drain();

Tasks

Use definePublishTask() for payload-carrying tasks:

const task = definePublishTask<{ name: string }>("echo");

Use defineSingletonTask() for singleton work:

const task = defineSingletonTask("singleton_echo");

Backends

InMemoryBackend

Good for tests and local development.

SqliteBackend

Durable storage for single-process setups.

const backend = await SqliteBackend.connect("sqlite:///tmp/bellows.sqlite");
await backend.initialize();

PostgresBackend

Durable storage with LISTEN / NOTIFY signaling.

const backend = await PostgresBackend.connect(
  "postgres://postgres:postgres@localhost:5432/postgres",
);
await backend.initialize();

Testing

Run the test suite:

pnpm test