Bun Package Manager

Introduction

The JavaScript ecosystem has long been dominated by npm and Yarn for dependency management. But with the rise of Bun.js—a new JavaScript runtime built for performance—comes a fresh take on package management. Bun Package Manager is designed to be incredibly fast, efficient, and easy to use. Whether you're managing single-page apps or full-stack projects, Bun's package manager simplifies dependency handling with modern tooling.

What Is Bun Package Manager?

Bun Package Manager is Bun’s native solution for installing, updating, and managing JavaScript and TypeScript dependencies. Unlike npm or Yarn, it integrates tightly with the Bun runtime and offers features like automatic transpilation, dependency caching, and blazing-fast installation using a custom HTTP loader.

Getting Started: bun init

To begin a new Bun project, you can use the bun init command. This sets up a minimal package.json and prepares your workspace:

# Initialize a new Bun project
bun init

It’ll prompt you for details like project name, entry point, and license. Once completed, your project is ready for adding dependencies.

Installing Packages with Bun

Installing packages in Bun is extremely fast. You can use the bun add command just like npm install or yarn add.

# Install a single package
bun add axios

# Install multiple packages
bun add express dotenv cors

It automatically updates your package.json and generates a bun.lockb lock file for reproducibility.

Removing Packages

To remove an installed package, Bun uses the bun remove command:

# Remove a package
bun remove axios

This will cleanly update your dependencies and remove the package from the lock file and node_modules (if any).

Understanding bun.lockb

Unlike package-lock.json or yarn.lock, Bun uses a binary lockfile called bun.lockb. This lockfile ensures deterministic installs and is optimized for speed during resolution and fetching.

Using bun install

You can install all project dependencies by running:

# Install all dependencies listed in package.json
bun install

This command is significantly faster than npm or yarn due to Bun’s parallel downloader and caching strategies.

Installing Dev Dependencies

You can install development-only packages using the --dev flag:

# Install as a dev dependency
bun add typescript --dev

Package Scripts in Bun

Just like npm, Bun supports running scripts defined in package.json:

"scripts": {
  "dev": "bun run index.ts",
  "build": "bun build"
}

To execute them, use:

bun run dev

Using Monorepos with Bun

Bun supports workspaces out of the box, making monorepo management simple and effective. Just define a workspaces array in the root package.json:

{
  "name": "my-monorepo",
  "workspaces": ["packages/*"]
}

Comparing Bun with npm and Yarn

Here’s how Bun compares to other popular package managers:

Best Practices with Bun Package Manager

• Always commit your bun.lockb file to version control.
• Use --dev for development-only tools and compilers.
• Run bun install before pushing to CI/CD for reproducible builds.
• Explore bun run to create seamless workflows and scripts.

Conclusion

The Bun Package Manager is a powerful and performance-focused tool that can significantly boost your JavaScript development workflow. With rapid installs, a smart lockfile system, and native support for workspaces, Bun is not just a runtime—it’s an entire toolkit. Whether you're building small apps or large-scale systems, mastering the Bun Package Manager will help you streamline your process and embrace a modern JavaScript experience.