jarle/Bun Single-file executable
skills/bun-bundler-executables/SKILL.md
Generate standalone executables from TypeScript or JavaScript files with Bun
$ install --global
skillsauthnpx skillsauth add jarle/bun-skills Bun Single-file executableInstall this skill globally with one command. Works with Claude Code, Cursor, and Windsurf.
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Last scanned: Apr 6, 2026, 2:18 AM6.0s1 file scanned
SKILL.md
- name:
- Bun Single-file executable
- description:
- Generate standalone executables from TypeScript or JavaScript files with Bun
Single-file executable
Generate standalone executables from TypeScript or JavaScript files with Bun
Bun's bundler implements a --compile flag for generating a standalone binary from a TypeScript or JavaScript file.
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.
Cross-compile to other platforms
The --target flag lets you compile your standalone executable for a different operating system, architecture, or version of Bun than the machine you're running bun build on.
To build for Linux x64 (most servers):
<Tabs> <Tab title="CLI"> ```bash icon="terminal" terminal theme={"theme":{"light":"github-light","dark":"dracula"}} bun build --compile --target=bun-linux-x64 ./index.ts --outfile myapp# To support CPUs from before 2013, use the baseline version (nehalem)
bun build --compile --target=bun-linux-x64-baseline ./index.ts --outfile myapp
# To explicitly only support CPUs from 2013 and later, use the modern version (haswell)
# modern is faster, but baseline is more compatible.
bun build --compile --target=bun-linux-x64-modern ./index.ts --outfile myapp
```
// Baseline (pre-2013 CPUs)
await Bun.build({
entrypoints: ["./index.ts"],
compile: {
target: "bun-linux-x64-baseline",
outfile: "./myapp",
},
});
// Modern (2013+ CPUs, faster)
await Bun.build({
entrypoints: ["./index.ts"],
compile: {
target: "bun-linux-x64-modern",
outfile: "./myapp",
},
});
```
To build for Linux ARM64 (e.g. Graviton or Raspberry Pi):
<Tabs> <Tab title="CLI"> ```bash icon="terminal" terminal theme={"theme":{"light":"github-light","dark":"dracula"}} # Note: the default architecture is x64 if no architecture is specified. bun build --compile --target=bun-linux-arm64 ./index.ts --outfile myapp ``` </Tab> <Tab title="JavaScript"> ```ts build.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}} await Bun.build({ entrypoints: ["./index.ts"], compile: { target: "bun-linux-arm64", outfile: "./myapp", }, }); ``` </Tab> </Tabs>To build for Windows x64:
<Tabs> <Tab title="CLI"> ```bash icon="terminal" terminal theme={"theme":{"light":"github-light","dark":"dracula"}} bun build --compile --target=bun-windows-x64 ./path/to/my/app.ts --outfile myapp# To support CPUs from before 2013, use the baseline version (nehalem)
bun build --compile --target=bun-windows-x64-baseline ./path/to/my/app.ts --outfile myapp
# To explicitly only support CPUs from 2013 and later, use the modern version (haswell)
bun build --compile --target=bun-windows-x64-modern ./path/to/my/app.ts --outfile myapp
# note: if no .exe extension is provided, Bun will automatically add it for Windows executables
```
// Baseline or modern variants
await Bun.build({
entrypoints: ["./path/to/my/app.ts"],
compile: {
target: "bun-windows-x64-baseline",
outfile: "./myapp",
},
});
```
To build for macOS arm64:
<Tabs> <Tab title="CLI"> ```bash icon="terminal" terminal theme={"theme":{"light":"github-light","dark":"dracula"}} bun build --compile --target=bun-darwin-arm64 ./path/to/my/app.ts --outfile myapp ``` </Tab> <Tab title="JavaScript"> ```ts build.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}} await Bun.build({ entrypoints: ["./path/to/my/app.ts"], compile: { target: "bun-darwin-arm64", outfile: "./myapp", }, }); ``` </Tab> </Tabs>To build for macOS x64:
<Tabs> <Tab title="CLI"> ```bash icon="terminal" terminal theme={"theme":{"light":"github-light","dark":"dracula"}} bun build --compile --target=bun-darwin-x64 ./path/to/my/app.ts --outfile myapp ``` </Tab> <Tab title="JavaScript"> ```ts build.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}} await Bun.build({ entrypoints: ["./path/to/my/app.ts"], compile: { target: "bun-darwin-x64", outfile: "./myapp", }, }); ``` </Tab> </Tabs>Supported targets
The order of the --target flag does not matter, as long as they're delimited by a -.
| --target | Operating System | Architecture | Modern | Baseline | Libc | | --------------------- | ---------------- | ------------ | ------ | -------- | ----- | | bun-linux-x64 | Linux | x64 | ✅ | ✅ | glibc | | bun-linux-arm64 | Linux | arm64 | ✅ | N/A | glibc | | bun-windows-x64 | Windows | x64 | ✅ | ✅ | - | | ~~bun-windows-arm64~~ | ~~Windows~~ | ~~arm64~~ | ❌ | ❌ | - | | bun-darwin-x64 | macOS | x64 | ✅ | ✅ | - | | bun-darwin-arm64 | macOS | arm64 | ✅ | N/A | - | | bun-linux-x64-musl | Linux | x64 | ✅ | ✅ | musl | | bun-linux-arm64-musl | Linux | arm64 | ✅ | N/A | musl |
<Warning> On x64 platforms, Bun uses SIMD optimizations which require a modern CPU supporting AVX2 instructions. The `-baseline` build of Bun is for older CPUs that don't support these optimizations. Normally, when you install Bun we automatically detect which version to use but this can be harder to do when cross-compiling since you might not know the target CPU. You usually don't need to worry about it on Darwin x64, but it is relevant for Windows x64 and Linux x64. If you or your users see `"Illegal instruction"` errors, you might need to use the baseline version. </Warning>Build-time constants
Use the --define flag to inject build-time constants into your executable, such as version numbers, build timestamps, or configuration values:
These constants are embedded directly into your compiled binary at build time, providing zero runtime overhead and enabling dead code elimination optimizations.
<Note> For comprehensive examples and advanced patterns, see the [Build-time constants guide](/guides/runtime/build-time-constants). </Note>Deploying to production
Compiled executables reduce memory usage and improve Bun's start time.
Normally, Bun reads and transpiles JavaScript and TypeScript files on import and require. This is part of what makes so much of Bun "just work", but it's not free. It costs time and memory to read files from disk, resolve file paths, parse, transpile, and print source code.
With compiled executables, you can move that cost from runtime to build-time.
When deploying to production, we recommend the following:
<Tabs> <Tab title="CLI"> ```bash icon="terminal" terminal theme={"theme":{"light":"github-light","dark":"dracula"}} bun build --compile --minify --sourcemap ./path/to/my/app.ts --outfile myapp ``` </Tab> <Tab title="JavaScript"> ```ts build.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}} await Bun.build({ entrypoints: ["./path/to/my/app.ts"], compile: { outfile: "./myapp", }, minify: true, sourcemap: "linked", }); ``` </Tab> </Tabs>Bytecode compilation
To improve startup time, enable bytecode compilation:
<Tabs> <Tab title="CLI"> ```bash icon="terminal" terminal theme={"theme":{"light":"github-light","dark":"dracula"}} bun build --compile --minify --sourcemap --bytecode ./path/to/my/app.ts --outfile myapp ``` </Tab> <Tab title="JavaScript"> ```ts build.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}} await Bun.build({ entrypoints: ["./path/to/my/app.ts"], compile: { outfile: "./myapp", }, minify: true, sourcemap: "linked", bytecode: true, }); ``` </Tab> </Tabs>Using bytecode compilation, tsc starts 2x faster:
Bytecode compilation moves parsing overhead for large input files from runtime to bundle time. Your app starts faster, in exchange for making the bun build command a little slower. It doesn't obscure source code.
<Note>Bytecode compilation supports both cjs and esm formats when used with --compile.</Note>
What do these flags do?
The --minify argument optimizes the size of the transpiled output code. If you have a large application, this can save megabytes of space. For smaller applications, it might still improve start time a little.
The --sourcemap argument embeds a sourcemap compressed with zstd, so that errors & stacktraces point to their original locations instead of the transpiled location. Bun will automatically decompress & resolve the sourcemap when an error occurs.
The --bytecode argument enables bytecode compilation. Every time you run JavaScript code in Bun, JavaScriptCore (the engine) will compile your source code into bytecode. We can move this parsing work from runtime to bundle time, saving you startup time.
Embedding runtime arguments
--compile-exec-argv="args" - Embed runtime arguments that are available via process.execArgv:
// In the compiled app
console.log(process.execArgv); // ["--smol", "--user-agent=MyBot"]
Runtime arguments via BUN_OPTIONS
The BUN_OPTIONS environment variable is applied to standalone executables, allowing you to pass runtime flags without recompiling:
# Enable CPU profiling on a compiled executable
BUN_OPTIONS="--cpu-prof" ./myapp
# Enable heap profiling with markdown output
BUN_OPTIONS="--heap-prof-md" ./myapp
# Combine multiple flags
BUN_OPTIONS="--smol --cpu-prof-md" ./myapp
This is useful for debugging or profiling production executables without rebuilding them.
Automatic config loading
Standalone executables can automatically load configuration files from the directory where they are run. By default:
tsconfig.jsonandpackage.jsonloading is disabled — these are typically only needed at development time, and the bundler already uses them when compiling.envandbunfig.tomlloading is enabled — these often contain runtime configuration that may vary per deployment
Enabling config loading at runtime
If your executable needs to read tsconfig.json or package.json at runtime, you can opt in with the new CLI flags:
# Enable runtime loading of tsconfig.json
bun build --compile --compile-autoload-tsconfig ./app.ts --outfile myapp
# Enable runtime loading of package.json
bun build --compile --compile-autoload-package-json ./app.ts --outfile myapp
# Enable both
bun build --compile --compile-autoload-tsconfig --compile-autoload-package-json ./app.ts --outfile myapp
Disabling config loading at runtime
To disable .env or bunfig.toml loading for deterministic execution:
# Disable bunfig.toml loading
bun build --compile --no-compile-autoload-bunfig ./app.ts --outfile myapp
# Disable all config loading
bun build --compile --no-compile-autoload-dotenv --no-compile-autoload-bunfig ./app.ts --outfile myapp
```
// .env and bunfig.toml are enabled by default
autoloadDotenv: false, // Disable .env loading
autoloadBunfig: false, // Disable bunfig.toml loading
outfile: "./myapp",
},
});
```
Act as the Bun CLI
<Note>New in Bun v1.2.16</Note>
You can run a standalone executable as if it were the bun CLI itself by setting the BUN_BE_BUN=1 environment variable. When this variable is set, the executable will ignore its bundled entrypoint and instead expose all the features of Bun's CLI.
For example, consider an executable compiled from a simple script:
echo "console.log(\"you shouldn't see this\");" > such-bun.js
bun build --compile ./such-bun.js
[3ms] bundle 1 modules
[89ms] compile such-bun
Normally, running ./such-bun with arguments would execute the script.
# Executable runs its own entrypoint by default
./such-bun install
you shouldn't see this
However, with the BUN_BE_BUN=1 environment variable, it acts just like the bun binary:
# With the env var, the executable acts like the `bun` CLI
BUN_BE_BUN=1 ./such-bun install
bun install v1.2.16-canary.1 (1d1db811)
Checked 63 installs across 64 packages (no changes) [5.00ms]
This is useful for building CLI tools on top of Bun that may need to install packages, bundle dependencies, run different or local files and more without needing to download a separate binary or install bun.
Full-stack executables
<Note>New in Bun v1.2.17</Note>
Bun's --compile flag can create standalone executables that contain both server and client code, making it ideal for full-stack applications. When you import an HTML file in your server code, Bun automatically bundles all frontend assets (JavaScript, CSS, etc.) and embeds them into the executable. When Bun sees the HTML import on the server, it kicks off a frontend build process to bundle JavaScript, CSS, and other assets.
const server = serve({ routes: { "/": index, "/api/hello": { GET: () => Response.json({ message: "Hello from API" }) }, }, });
console.log(Server running at http://localhost:${server.port});
```html index.html icon="file-code" theme={"theme":{"light":"github-light","dark":"dracula"}}
<!DOCTYPE html>
<html>
<head>
<title>My App</title>
<link rel="stylesheet" href="./styles.css" />
</head>
<body>
<h1>Hello World</h1>
<script src="./app.ts"></script>
</body>
</html>
console.log("Hello from the client!");
body {
background-color: #f0f0f0;
}
To build this into a single executable:
<Tabs> <Tab title="CLI"> ```bash terminal icon="terminal" theme={"theme":{"light":"github-light","dark":"dracula"}} bun build --compile ./server.ts --outfile myapp ``` </Tab> <Tab title="JavaScript"> ```ts build.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}} await Bun.build({ entrypoints: ["./server.ts"], compile: { outfile: "./myapp", }, }); ``` </Tab> </Tabs>This creates a self-contained binary that includes:
- Your server code
- The Bun runtime
- All frontend assets (HTML, CSS, JavaScript)
- Any npm packages used by your server
The result is a single file that can be deployed anywhere without needing Node.js, Bun, or any dependencies installed. Just run:
./myapp
Bun automatically handles serving the frontend assets with proper MIME types and cache headers. The HTML import is replaced with a manifest object that Bun.serve uses to efficiently serve pre-bundled assets.
For more details on building full-stack applications with Bun, see the full-stack guide.
Worker
To use workers in a standalone executable, add the worker's entrypoint to the build:
<Tabs> <Tab title="CLI"> ```bash terminal icon="terminal" theme={"theme":{"light":"github-light","dark":"dracula"}} bun build --compile ./index.ts ./my-worker.ts --outfile myapp ``` </Tab> <Tab title="JavaScript"> ```ts build.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}} await Bun.build({ entrypoints: ["./index.ts", "./my-worker.ts"], compile: { outfile: "./myapp", }, }); ``` </Tab> </Tabs>Then, reference the worker in your code:
console.log("Hello from Bun!");
// Any of these will work:
new Worker("./my-worker.ts");
new Worker(new URL("./my-worker.ts", import.meta.url));
new Worker(new URL("./my-worker.ts", import.meta.url).href);
When you add multiple entrypoints to a standalone executable, they will be bundled separately into the executable.
In the future, we may automatically detect usages of statically-known paths in new Worker(path) and then bundle those into the executable, but for now, you'll need to add it to the shell command manually like the above example.
If you use a relative path to a file not included in the standalone executable, it will attempt to load that path from disk relative to the current working directory of the process (and then error if it doesn't exist).
SQLite
You can use bun:sqlite imports with bun build --compile.
By default, the database is resolved relative to the current working directory of the process.
import db from "./my.db" with { type: "sqlite" };
console.log(db.query("select * from users LIMIT 1").get());
That means if the executable is located at /usr/bin/hello, the user's terminal is located at /home/me/Desktop, it will look for /home/me/Desktop/my.db.
cd /home/me/Desktop
./hello
Embed assets & files
Standalone executables support embedding files directly into the binary. This lets you ship a single executable that contains images, JSON configs, templates, or any other assets your application needs.
How it works
Use the with { type: "file" } import attribute to embed a file:
import icon from "./icon.png" with { type: "file" };
console.log(icon);
// During development: "./icon.png"
// After compilation: "$bunfs/icon-a1b2c3d4.png" (internal path)
The import returns a path string that points to the embedded file. At build time, Bun:
- Reads the file contents
- Embeds the data into the executable
- Replaces the import with an internal path (prefixed with
$bunfs/)
You can then read this embedded file using Bun.file() or Node.js fs APIs.
Reading embedded files with Bun.file()
Bun.file() is the recommended way to read embedded files:
import icon from "./icon.png" with { type: "file" };
import { file } from "bun";
// Get file contents as different types
const bytes = await file(icon).arrayBuffer(); // ArrayBuffer
const text = await file(icon).text(); // string (for text files)
const blob = file(icon); // Blob
// Stream the file in a response
export default {
fetch(req) {
return new Response(file(icon), {
headers: { "Content-Type": "image/png" },
});
},
};
Reading embedded files with Node.js fs
Embedded files work seamlessly with Node.js file system APIs:
import icon from "./icon.png" with { type: "file" };
import config from "./config.json" with { type: "file" };
import { readFileSync, promises as fs } from "node:fs";
// Synchronous read
const iconBuffer = readFileSync(icon);
// Async read
const configData = await fs.readFile(config, "utf-8");
const parsed = JSON.parse(configData);
// Check file stats
const stats = await fs.stat(icon);
console.log(`Icon size: ${stats.size} bytes`);
Practical examples
Embedding a JSON config file
import configPath from "./default-config.json" with { type: "file" };
import { file } from "bun";
// Load the embedded default configuration
const defaultConfig = await file(configPath).json();
// Merge with user config if it exists
const userConfig = await file("./user-config.json")
.json()
.catch(() => ({}));
const config = { ...defaultConfig, ...userConfig };
Serving static assets in an HTTP server
Use static routes in Bun.serve() for efficient static file serving:
import favicon from "./favicon.ico" with { type: "file" };
import logo from "./logo.png" with { type: "file" };
import styles from "./styles.css" with { type: "file" };
import { file, serve } from "bun";
serve({
static: {
"/favicon.ico": file(favicon),
"/logo.png": file(logo),
"/styles.css": file(styles),
},
fetch(req) {
return new Response("Not found", { status: 404 });
},
});
Bun automatically handles Content-Type headers and caching for static routes.
Embedding templates
import templatePath from "./email-template.html" with { type: "file" };
import { file } from "bun";
async function sendWelcomeEmail(user: { name: string; email: string }) {
const template = await file(templatePath).text();
const html = template.replace("{{name}}", user.name).replace("{{email}}", user.email);
// Send email with the rendered template...
}
Embedding binary files
import wasmPath from "./processor.wasm" with { type: "file" };
import fontPath from "./font.ttf" with { type: "file" };
import { file } from "bun";
// Load a WebAssembly module
const wasmBytes = await file(wasmPath).arrayBuffer();
const wasmModule = await WebAssembly.instantiate(wasmBytes);
// Read binary font data
const fontData = await file(fontPath).bytes();
Embed SQLite databases
If your application wants to embed a SQLite database into the compiled executable, set type: "sqlite" in the import attribute and the embed attribute to "true".
The database file must already exist on disk. Then, import it in your code:
import myEmbeddedDb from "./my.db" with { type: "sqlite", embed: "true" };
console.log(myEmbeddedDb.query("select * from users LIMIT 1").get());
Finally, compile it into a standalone executable:
bun build --compile ./index.ts --outfile mycli
In the compiled executable, the embedded database is read-write, but all changes are lost when the executable exits (since it's stored in memory).
Embed N-API Addons
You can embed .node files into executables.
const addon = require("./addon.node");
console.log(addon.hello());
Unfortunately, if you're using @mapbox/node-pre-gyp or other similar tools, you'll need to make sure the .node file is directly required or it won't bundle correctly.
Embed directories
To embed a directory with bun build --compile, include file patterns in your build:
// Expand glob pattern to file list
const glob = new Glob("./public/**/*.png");
const pngFiles = Array.from(glob.scanSync("."));
await Bun.build({
entrypoints: ["./index.ts", ...pngFiles],
compile: {
outfile: "./myapp",
},
});
```
Then, you can reference the files in your code:
import icon from "./public/assets/icon.png" with { type: "file" };
import { file } from "bun";
export default {
fetch(req) {
// Embedded files can be streamed from Response objects
return new Response(file(icon));
},
};
This is honestly a workaround, and we expect to improve this in the future with a more direct API.
Listing embedded files
Bun.embeddedFiles gives you access to all embedded files as Blob objects:
import "./icon.png" with { type: "file" };
import "./data.json" with { type: "file" };
import "./template.html" with { type: "file" };
import { embeddedFiles } from "bun";
// List all embedded files
for (const blob of embeddedFiles) {
console.log(`${blob.name} - ${blob.size} bytes`);
}
// Output:
// icon-a1b2c3d4.png - 4096 bytes
// data-e5f6g7h8.json - 256 bytes
// template-i9j0k1l2.html - 1024 bytes
Each item in Bun.embeddedFiles is a Blob with a name property:
embeddedFiles: ReadonlyArray<Blob>;
This is useful for dynamically serving all embedded assets using static routes:
import "./public/favicon.ico" with { type: "file" };
import "./public/logo.png" with { type: "file" };
import "./public/styles.css" with { type: "file" };
import { embeddedFiles, serve } from "bun";
// Build static routes from all embedded files
const staticRoutes: Record<string, Blob> = {};
for (const blob of embeddedFiles) {
// Remove hash from filename: "icon-a1b2c3d4.png" -> "icon.png"
const name = blob.name.replace(/-[a-f0-9]+\./, ".");
staticRoutes[`/${name}`] = blob;
}
serve({
static: staticRoutes,
fetch(req) {
return new Response("Not found", { status: 404 });
},
});
Content hash
By default, embedded files have a content hash appended to their name. This is useful for situations where you want to serve the file from a URL or CDN and have fewer cache invalidation issues. But sometimes, this is unexpected and you might want the original name instead:
To disable the content hash, configure asset naming:
<Tabs> <Tab title="CLI"> ```bash terminal icon="terminal" theme={"theme":{"light":"github-light","dark":"dracula"}} bun build --compile --asset-naming="[name].[ext]" ./index.ts ``` </Tab> <Tab title="JavaScript"> ```ts build.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}} await Bun.build({ entrypoints: ["./index.ts"], compile: { outfile: "./myapp", }, naming: { asset: "[name].[ext]", }, }); ``` </Tab> </Tabs>Minification
To trim down the size of the executable, enable minification:
<Tabs> <Tab title="CLI"> ```bash terminal icon="terminal" theme={"theme":{"light":"github-light","dark":"dracula"}} bun build --compile --minify ./index.ts --outfile myapp ``` </Tab> <Tab title="JavaScript"> ```ts build.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}} await Bun.build({ entrypoints: ["./index.ts"], compile: { outfile: "./myapp", }, minify: true, // Enable all minification });// Or granular control:
await Bun.build({
entrypoints: ["./index.ts"],
compile: {
outfile: "./myapp",
},
minify: {
whitespace: true,
syntax: true,
identifiers: true,
},
});
```
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.
Windows-specific flags
When compiling a standalone executable on Windows, there are platform-specific options to customize metadata on the generated .exe file:
# Hide console window (for GUI apps)
bun build --compile --windows-hide-console ./app.ts --outfile myapp
```
Available Windows options:
icon- Path to.icofile for the executable iconhideConsole- Disable the background terminal (for GUI apps)title- Application title in file propertiespublisher- Publisher name in file propertiesversion- Version string in file propertiesdescription- Description in file propertiescopyright- Copyright notice in file properties
<Warning>These flags currently cannot be used when cross-compiling because they depend on Windows APIs.</Warning>
Code signing on macOS
To codesign a standalone executable on macOS (which fixes Gatekeeper warnings), use the codesign command.
codesign --deep --force -vvvv --sign "XXXXXXXXXX" ./myapp
We recommend including an entitlements.plist file with JIT permissions.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>com.apple.security.cs.allow-jit</key>
<true/>
<key>com.apple.security.cs.allow-unsigned-executable-memory</key>
<true/>
<key>com.apple.security.cs.disable-executable-page-protection</key>
<true/>
<key>com.apple.security.cs.allow-dyld-environment-variables</key>
<true/>
<key>com.apple.security.cs.disable-library-validation</key>
<true/>
</dict>
</plist>
To codesign with JIT support, pass the --entitlements flag to codesign.
codesign --deep --force -vvvv --sign "XXXXXXXXXX" --entitlements entitlements.plist ./myapp
After codesigning, verify the executable:
codesign -vvv --verify ./myapp
./myapp: valid on disk
./myapp: satisfies its Designated Requirement
<Warning>Codesign support requires Bun v1.2.4 or newer.</Warning>
Code splitting
Standalone executables support code splitting. Use --compile with --splitting to create an executable that loads code-split chunks at runtime.
export function hello() {
console.log("Lazy module loaded");
}
./build/entry
Entrypoint loaded
Lazy module loaded
Using plugins
Plugins work with standalone executables, allowing you to transform files during the build process:
import type { BunPlugin } from "bun";
const envPlugin: BunPlugin = {
name: "env-loader",
setup(build) {
build.onLoad({ filter: /\.env\.json$/ }, async args => {
// Transform .env.json files into validated config objects
const env = await Bun.file(args.path).json();
return {
contents: `export default ${JSON.stringify(env)};`,
loader: "js",
};
});
},
};
await Bun.build({
entrypoints: ["./cli.ts"],
compile: {
outfile: "./mycli",
},
plugins: [envPlugin],
});
Example use case - embedding environment config at build time:
import config from "./config.env.json";
console.log(`Running in ${config.environment} mode`);
console.log(`API endpoint: ${config.apiUrl}`);
Plugins can perform any transformation: compile YAML/TOML configs, inline SQL queries, generate type-safe API clients, or preprocess templates. Refer to the plugin documentation for more details.
Unsupported CLI arguments
Currently, the --compile flag can only accept a single entrypoint at a time and does not support the following flags:
--outdir— useoutfileinstead (except when using with--splitting).--public-path--target=node--target=browser(without HTML entrypoints — see Standalone HTML for--compile --target=browserwith.htmlfiles)--no-bundle- we always bundle everything into the executable.
API reference
The compile option in Bun.build() accepts three forms:
interface BuildConfig {
entrypoints: string[];
compile: boolean | Bun.Build.Target | CompileBuildOptions;
// ... other BuildConfig options (minify, sourcemap, define, plugins, etc.)
}
interface CompileBuildOptions {
target?: Bun.Build.Target; // Cross-compilation target
outfile?: string; // Output executable path
execArgv?: string[]; // Runtime arguments (process.execArgv)
autoloadTsconfig?: boolean; // Load tsconfig.json (default: false)
autoloadPackageJson?: boolean; // Load package.json (default: false)
autoloadDotenv?: boolean; // Load .env files (default: true)
autoloadBunfig?: boolean; // Load bunfig.toml (default: true)
windows?: {
icon?: string; // Path to .ico file
hideConsole?: boolean; // Hide console window
title?: string; // Application title
publisher?: string; // Publisher name
version?: string; // Version string
description?: string; // Description
copyright?: string; // Copyright notice
};
}
Usage forms:
// Simple boolean - compile for current platform (uses entrypoint name as output)
compile: true
// Target string - cross-compile (uses entrypoint name as output)
compile: "bun-linux-x64"
// Full options object - specify outfile and other options
compile: {
target: "bun-linux-x64",
outfile: "./myapp",
}
Supported targets
type Target =
| "bun-darwin-x64"
| "bun-darwin-x64-baseline"
| "bun-darwin-arm64"
| "bun-linux-x64"
| "bun-linux-x64-baseline"
| "bun-linux-x64-modern"
| "bun-linux-arm64"
| "bun-linux-x64-musl"
| "bun-linux-arm64-musl"
| "bun-windows-x64"
| "bun-windows-x64-baseline"
| "bun-windows-x64-modern";
Complete example
import type { BunPlugin } from "bun";
const myPlugin: BunPlugin = {
name: "my-plugin",
setup(build) {
// Plugin implementation
},
};
const result = await Bun.build({
entrypoints: ["./src/cli.ts"],
compile: {
target: "bun-linux-x64",
outfile: "./dist/mycli",
execArgv: ["--smol"],
autoloadDotenv: false,
autoloadBunfig: false,
},
minify: true,
sourcemap: "linked",
bytecode: true,
define: {
"process.env.NODE_ENV": JSON.stringify("production"),
VERSION: JSON.stringify("1.0.0"),
},
plugins: [myPlugin],
});
if (result.success) {
console.log("Build successful:", result.outputs[0].path);
}
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