TypeScript

To add coding intellisense to your editor, install the types package:

pnpm

pnpm add kyushu-types -D

npm

npm install kyushu-types -D

yarn

yarn add kyushu-types -D

ExportedHandler

The default export shape expected by Kyushu workers.

import type { ExportedHandler } from "kyushu-types";

export default {
  async fetch(request, env) {
    return {
      status: 200,
      body: "Hello, world!",
    };
  },
} satisfies ExportedHandler;

WorkerRequest

The incoming HTTP request passed to the fetch handler.

Field	Type	Description
method	WorkerMethod	HTTP method (GET, POST, etc.)
url	string	Full request URL
headers	Record<string, string> | undefined	Request headers
body	string | ArrayBuffer | Uint8Array | undefined	Request body

WorkerResponse

The HTTP response returned by the fetch handler.

Field	Type	Description
status	number | undefined	HTTP status code (default: 200)
body	string | ArrayBuffer | Uint8Array | undefined	Response body
headers	Record<string, string> | undefined	Response headers

Env

The environment object passed as the second argument to the fetch handler.

Field	Type	Description
ASSETS	EnvAssets	Provides features to handle assets.

EnvAssets

Provides access to static assets bundled into the worker at build time or read from mounted file system. See the Static Assets guide for the instructions to set up the former.

Method	Signature	Description
fetch	(request: WorkerRequest, options?: AssetFetchOptions) => Promise<WorkerResponse>	Serve a static asset. Defaults to handling assets from "memory".

AssetFetchOptions

The default approach to serve static asset is bundling and serving them to memory. But you might need to read those from the file-system, notably if you hit some memory limitation when bundling the worker.

Field	Type	Description
src	"memory" | "fs"	The source to fetch assets from.

WorkerMethod

type WorkerMethod = "GET" | "POST" | "PUT" | "PATCH" | "DELETE" | "HEAD" | "OPTIONS";

Runtime validation

The worker validates both the incoming request and outgoing response using Zod schemas at the Wasm boundary. If your handler returns an unexpected shape, you get a clear error rather than a silent failure.

The schemas are also exported from kyushu-types if you need them directly:

import { WorkerRequestSchema, WorkerResponseSchema, ExportedHandlerSchema } from "kyushu-types";