Bun.js Setup Guide

Introduction to Bun.js Setup

Setting up Bun.js is incredibly straightforward compared to traditional JavaScript environments. Designed for speed and simplicity, Bun combines a runtime, bundler, package manager, and test runner in one binary. This guide will walk you through installing Bun.js and getting your development environment ready in just a few minutes.

System Requirements

Before installing Bun.js, make sure you have the following:

• Operating System: macOS, Linux, or Windows (WSL2 supported)
• Shell: bash, zsh, or similar terminal environment
• Basic understanding of JavaScript or TypeScript (optional but helpful)

Step 1: Install Bun.js

To install Bun.js, simply open your terminal and run the official install script:

curl -fsSL https://bun.sh/install | bash

This will download and install the Bun binary and update your shell profile (like .bashrc or .zshrc) automatically.

Step 2: Verify Installation

After installation, confirm that Bun was installed correctly by running:

bun --version

You should see the current version number of Bun displayed in your terminal.

Step 3: Initialize a New Project

Bun offers a convenient command to set up a new project structure. To create a new project, run:

bun init

You'll be prompted to enter a project name, description, and other basic configurations. Bun will then generate a project folder with a ready-to-use structure, including:

• index.ts – Entry point
• bun.lockb – Lock file
• package.json – Metadata and dependencies

Step 4: Add Dependencies

Installing packages with Bun is faster than npm or yarn. For example, to add React:

bun add react react-dom

To remove a package:

bun remove package-name

Step 5: Run Your Project

You can run any file directly using the bun command. For example, if your main file is index.ts:

bun run index.ts

Bun will automatically handle TypeScript, JSX, and other modern syntax during execution.

Step 6: Using TypeScript with Bun

Bun has built-in TypeScript support, so no extra config is needed to run .ts files. However, you can still add a tsconfig.json file if your project requires specific compiler options:

{
  "compilerOptions": {
    "target": "ESNext",
    "module": "ESNext",
    "strict": true
  }
}

Step 7: Create a Basic Server

Here’s how you can set up a minimal HTTP server using Bun:

// index.ts
export default {
  port: 3000,
  fetch(request: Request): Response {
    return new Response("Hello from Bun.js Setup Guide!");
  }
};

Now run the server:

bun run index.ts

Visit http://localhost:3000 in your browser to see the response.

Conclusion

Bun.js makes it easy to go from zero to a running app in just a few commands. With its ultra-fast runtime, native TypeScript support, built-in tools, and simplified workflows, Bun saves time and reduces complexity for developers. Whether you're building full-stack apps or lightweight APIs, setting up Bun is a smooth experience worth trying.

Ready to move beyond setup? Check out advanced guides on using Bun with frameworks like React, building REST APIs, or deploying Bun-powered applications.