Bun

Executables

Bun's bundler implements a --compile flag for generating a standalone binary from a TypeScript or JavaScript file.

bash
cli.ts
bun build ./cli.ts --compile --outfile mycli
cli.ts
console.log("Hello world!");

This bundles cli.ts into an executable that can be executed directly:

$ ./mycli
Hello world!

All imported files and packages are bundled into the executable, along with a copy of the Bun runtime. All built-in Bun and Node.js APIs are supported.

Note — Currently, the --compile flag can only accept a single entrypoint at a time and does not support the following flags:

  • --outdir — use outfile instead.
  • --external
  • --splitting
  • --public-path

Embedding files

Standalone executables support embedding files.

To embed files into an executable with bun build --compile, import the file in your code

// this becomes an internal file path
import icon from "./icon.png";

import { file } from "bun";

export default {
  fetch(req) {
    return new Response(file(icon));
  },
};

You may need to specify a --loader for it to be treated as a "file" loader (so you get back a file path).

Embedded files can be read using Bun.file's functions or the Node.js fs.readFile function (in "node:fs").

Minification

To trim down the size of the executable a little, pass --minify to bun build --compile. This uses Bun's minifier to reduce the code size. Overall though, Bun's binary is still way too big and we need to make it smaller.