Worker

The Worker component lets you create a Cloudflare Worker.

Minimal example

sst.config.ts

new sst.cloudflare.Worker("MyWorker", {
  handler: "src/worker.handler"
});

Link resources

Link resources to the Worker. This will handle the credentials and allow you to access it in your handler.

sst.config.ts

const bucket = new sst.aws.Bucket("MyBucket");

new sst.cloudflare.Worker("MyWorker", {
  handler: "src/worker.handler",
  link: [bucket]
});

You can use the SDK to access the linked resources in your handler.

src/worker.ts

import { Resource } from "sst";

console.log(Resource.MyBucket.name);

Enable URLs

Enable worker URLs to invoke the worker over HTTP.

sst.config.ts

new sst.cloudflare.Worker("MyWorker", {
  handler: "src/worker.handler",
  url: true
});

Bundling

Customize how SST uses esbuild to bundle your worker code with the build property.

sst.config.ts

new sst.cloudflare.Worker("MyWorker", {
  handler: "src/worker.handler",
  build: {
    install: ["pg"]
  }
});

---

Constructor

new Worker(name, args, opts?)

Parameters

• name string

• args WorkerArgs

• opts? ComponentResourceOptions

WorkerArgs

build?

Type Input<Object>

• banner?

• esbuild?

• loader?

• minify?

Configure how your function is bundled.

SST bundles your worker code using esbuild. This tree shakes your code to only include what’s used.

build.banner?

Type Input<string>

Use this to insert a string at the beginning of the generated JS file.

{
  build: {
    banner: "console.log('Function starting')"
  }
}

build.esbuild?

Type Input<BuildOptions>

This allows you to customize esbuild config that is used.

Tip

Check out the JS tab in the code snippets in the esbuild docs for the BuildOptions.

build.loader?

Type Input<Record<string, Loader>>

Configure additional esbuild loaders for other file extensions. This is useful when your code is importing non-JS files like .png, .css, etc.

{
  build: {
    loader: {
     ".png": "file"
    }
  }
}

build.minify?

Type Input<boolean>

Default true

Disable if the worker code should be minified when bundled.

{
  build: {
    minify: false
  }
}

domain?

Type Input<string>

Set a custom domain for your Worker. Supports domains hosted on Cloudflare.

Tip

You can migrate an externally hosted domain to Cloudflare by following this guide.

{
  domain: "domain.com"
}

environment?

Type Input<Record<string, Input<string>>>

Key-value pairs that are set as Worker environment variables.

They can be accessed in your worker through env.<key>.

{
  environment: {
    DEBUG: "true"
  }
}

handler

Type Input<string>

Path to the handler file for the worker.

The handler path is relative to the root your repo or the sst.config.ts.

{
  handler: "packages/functions/src/worker.ts"
}

link?

Type Input<any[]>

Link resources to your worker. This will:

1. Handle the credentials needed to access the resources.
2. Allow you to access it in your site using the SDK.

Takes a list of components to link to the function.

{
  link: [bucket, stripeKey]
}

transform?

Type Object

• worker?

Transform how this component creates its underlying resources.

transform.worker?

Type WorkerScriptArgs | (args: WorkerScriptArgs, opts: ComponentResourceOptions, name: string) => void

Transform the Worker resource.

url?

Type Input<boolean>

Default false

Enable a dedicated endpoint for your Worker.

Properties

nodes

Type Object

• worker

The underlying resources this component creates.

nodes.worker

Type Output<WorkerScript>

The Cloudflare Worker script.

url

Type Output<undefined | string>

The Worker URL if url is enabled.

SDK

Use the SDK in your runtime to interact with your infrastructure.

---

Links

This is accessible through the Resource object in the SDK.

• url undefined | string

  The Worker URL if url is enabled.

Bindings

When you link a worker, say WorkerA, to another worker, WorkerB; it automatically creates a service binding between the workers. It allows WorkerA to call WorkerB without going through a publicly-accessible URL.

index.ts

import { Resource } from "sst";

await Resource.WorkerB.fetch(request);

Read more about binding Workers.