File System

Read and write files by mounting a host directory into the sandbox.

src/index.ts

import type { ExportedHandler } from "kyushu-types";
import { writeFileSync, readFileSync } from "node:fs";

export default {
  async fetch() {
    writeFileSync("/data/hello.txt", "Hello from Kyushu!");
    const content = readFileSync("/data/hello.txt", "utf8");

    return {
      status: 200,
      headers: { "content-type": "text/plain" },
      body: content,
    };
  },
} satisfies ExportedHandler;

Config

By default, the sandbox has no access to the host filesystem. Mount a directory to expose it to your worker.

kyushu.run.toml

[[mounts]]
host = "."
guest = "/"
writable = true

Note

Set writable = true to allow the worker to write files. Mounts are read-only by default.

Try it

Build and run the worker with its config.

kyu build && kyu run kyushu.run.toml

Then send a request to test it.

curl http://localhost:5987