Get started with Async Workloads
This page will help you get started with the Async Workloads extension. It describes how to enable the extension, write basic workloads, and send events to them.
# Key concepts
The Async Workloads extension turns Netlify serverless functions into durable, event-driven workloads. When you define workloads, you create serverless functions. Given this, the capabilities and limitations for serverless functions also apply to workloads. Any exceptions will be explicitly noted.
Learn more about serverless functions.
An Async Workload function is similar to a background function but is durable, event-driven, and offers more enhanced capabilities. The function runs asynchronously, so it will not return a Response object. Instead, the client can invoke the function by sending a matching event and the workload function can run its logic and persist any state it needs.
# Setup
To get started, install the Async Workloads extension for your team. After you install the extension, all sites on your team will be able to build Async Workloads functions.
Add the @netlify/async-workloads module to your project. This will provide the functionality and types for those using TypeScript.
npm install @netlify/async-workloads
pnpm add @netlify/async-workloads
yarn add @netlify/async-workloads
# Write an Async Workload function
Start by adding a serverless function to your project by creating the file in your functions directory.
A function file must be written using the JavaScript modules syntax and have a default export with a asyncWorkloadFn wrapped handler.
import { asyncWorkloadFn, AsyncWorkloadEvent, AsyncWorkloadConfig } from "@netlify/async-workloads";
export default asyncWorkloadFn((event: AsyncWorkloadEvent) => {
console.log('Hello, Async Workloads!');
});
export const asyncWorkloadConfig: AsyncWorkloadConfig = {
events: ['say-hello']
};
import { asyncWorkloadFn } from "@netlify/async-workloads";
export default asyncWorkloadFn((event) => {
console.log('Hello, Async Workloads!');
});
export const asyncWorkloadConfig = {
events: ['say-hello']
};
This workload will be called when the "say-hello" event is sent by a client. Once sent, this workload will run and log the message.
# Send your first event
Async Workloads provides a client library called AsyncWorkloadsClient that can be used to send events.
The basic flow is to instantiate the client and then send the message.
const client = new AsyncWorkloadsClient();
// optionally send data
await client.send('EVENT_NAME', {data: {}});
Typically, Async Workload functions are triggered by other serverless endpoints that respond to user actions on a website. When this occurs, the client is instantiated and used within that serverless endpoint after other checks are performed or data is aggregated.
The following example is a serverless function that can be called at the /say-hey route on the site. When the function is called, it will send the event to the Async Workloads system. At that point, the workload function defined above will run.
import type {Config} from "@netlify/functions";
import { AsyncWorkloadsClient } from "@netlify/async-workloads";
export default async (req: Request) => {
// do some work... authenticate the user, pull data, etc.
const client = new AsyncWorkloadsClient();
await client.send('say-hello');
return new Response('', { status: 200 });
};
export const config: Config = {
path: '/say-hey'
}
import { AsyncWorkloadsClient } from "@netlify/async-workloads";
export default async (req) => {
// do some work... authenticate the user, pull data, etc.
const client = new AsyncWorkloadsClient();
await client.send('say-hello');
return new Response('', { status: 200 });
};
export const config = {
path: '/say-hey'
}
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