#Alepha - Background

#Installation

Part of the alepha package. Import from alepha/background.

npm install alepha

#Overview

Fire-and-forget background work that should outlive the request that scheduled it, without blocking the response.

Inject {@link BackgroundTaskProvider} and call defer(() => …):

1protected readonly background = $inject(BackgroundTaskProvider);2 3createUser = $action({ handler: async ({ body }) => {4  const user = await this.users.create(body);5  this.background.defer(() => this.email.send(welcome(user))); // don't block6  return user;7}});

On Node/Vercel the event loop keeps the task alive. On Cloudflare Workers the workerd build swaps in {@link WorkerdBackgroundTaskProvider}, which wraps the task in executionCtx.waitUntil so the isolate isn't frozen at response time — the call site is identical either way.

#API Reference

#Providers

• BackgroundTaskProvider — Runs fire-and-forget work that should outlive the request that scheduled it
• WorkerdBackgroundTaskProvider — Cloudflare Workers variant of {@link BackgroundTaskProvider}.