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Install Bun

Runtime Package Manager Bundler Test Runner Guides Reference Blog Feedback

Overview

Deployment

Deploy on Vercel Deploy on Railway Deploy on Render Deploy on AWS Lambda Deploy on DigitalOcean Deploy on Google Cloud Run

Runtime & Debugging

TypeScript types Re-map import paths VS Code debugger Web debugger Heap snapshots Build-time constants Define constants GitHub Actions Codesign on macOS

Utilities

Upgrade Bun Detect Bun Get Bun version Hash password Generate UUID Base64 encoding Gzip compression DEFLATE compression Escape HTML Deep equality Sleep File URL to path Path to file URL Find executable path import.meta.dir import.meta.file import.meta.path Check entrypoint Get entrypoint path

Ecosystem & Frameworks

Astro with Bun Discord.js with Bun Docker with Bun Drizzle with Bun Gel with Bun Elysia with Bun Express with Bun Hono with Bun Mongoose with Bun Neon Drizzle with Bun Neon Serverless Postgres with Bun Next.js with Bun Nuxt with Bun PM2 with Bun Prisma ORM with Bun Prisma Postgres with Bun Qwik with Bun React with Bun Remix with Bun TanStack Start with Bun Sentry with Bun SolidStart with Bun SSR React with Bun StricJS with Bun SvelteKit with Bun systemd with Bun Vite with Bun Upstash with Bun

HTTP & Networking

HTTP Server with Bun Simple HTTP Server with Bun Fetch with Bun Hot reload an HTTP server Start a cluster of HTTP servers Configure TLS Proxy HTTP requests using fetch()Stream file response Upload files via HTTP using FormData Fetch with unix domain sockets Stream with iterators Server-Sent Events Stream with Node.js

WebSocket

Simple server Pub-sub server Contextual data Enable compression

Processes & System

Spawn child process Read stdout Read stderr Parse command-line arguments Read from stdin Spawn a child process and communicate using IPC Listen for CTRL+C OS signals Process uptime Run shell command Set time zone Set env variables Read env variables

Package Manager

Add a dependency Add a dev dependency Add an optional dependency Add a peer dependency Add a Git dependency Add a tarball dependency Install with alias Workspaces with Bun Override the default npm registry Configure a scoped registry Azure Artifacts with Bun JFrog Artifactory with Bun Add a trusted dependency Generate a yarn-compatible lockfile Migrate from npm to bun Configure git to diff Bun's lockfile Install Bun in GitHub Actions

Test Runner

Run tests Watch mode Migrate from Jest Mock functions Spy on methods Mock system time Snapshot testing Update snapshots Coverage reports Coverage threshold Concurrent test glob Skip tests Todo tests Test timeout Bail early Re-run tests Testing Library DOM tests Test Svelte

Runtime & Debugging

VS Code debugger Web debugger Heap snapshots Build-time constants Define constants GitHub Actions Codesign on macOS

Module System

Import JSON Import TOML Import YAML Import JSON5 Import HTML import.meta.dir import.meta.file import.meta.path Check entrypoint Get entrypoint path

File System

Read as string Read to Buffer Read to Uint8Array Read to ArrayBuffer Read JSON file Get MIME type Check file exists Watch directory Read as stream Write string to file Write Blob Write Response Append to file Incremental write Write stream Write to stdout Write file to stdout Copy file Delete file Delete files Delete directories

Utilities

Hash password Generate UUID Base64 encoding Gzip compression DEFLATE compression Escape HTML Deep equality Sleep File URL to path Path to file URL Find executable path

HTML Processing

Extract links using HTMLRewriter OpenGraph tags

Binary Data

ArrayBuffer to string ArrayBuffer to Buffer ArrayBuffer to Blob ArrayBuffer to Array ArrayBuffer to Uint8Array Buffer to string Buffer to ArrayBuffer Buffer to Blob Buffer to Uint8Array Buffer to ReadableStream Blob to string Blob to ArrayBuffer Blob to Uint8Array Blob to DataView Blob to ReadableStream Uint8Array to string Uint8Array to ArrayBuffer Uint8Array to Buffer Uint8Array to Blob Uint8Array to DataView Uint8Array to ReadableStream DataView to string

Streams

Stream to string Stream to JSON Stream to Blob Stream to Buffer Stream to ArrayBuffer Stream to Uint8Array Stream to array Readable to string Readable to JSON Readable to Blob Readable to Uint8Array Readable to ArrayBuffer

Overview

Guides

Code samples and walkthroughs for common tasks with Bun

Featured

Use Tanstack Start with Bun

Use Next.js with Bun

Build a frontend using Vite and Bun

Install TypeScript declarations for Bun

Write a simple HTTP server

Build a simple WebSocket server

All Guides

Deployment

Deploy Bun on Vercel

Deploy Bun on Railway

Deploy Bun on Render

Binary data

Convert an ArrayBuffer to an array of numbers

Convert an ArrayBuffer to a Blob

Convert an ArrayBuffer to a Buffer

Convert an ArrayBuffer to a string

Convert an ArrayBuffer to a Uint8Array

Convert a Blob to an ArrayBuffer

Convert a Blob to a DataView

Convert a Blob to a ReadableStream

Convert a Blob to a string

Convert a Blob to a Uint8Array

Convert a Buffer to an ArrayBuffer

Convert a Buffer to a blob

Convert a Buffer to a ReadableStream

Convert a Buffer to a string

Convert a Buffer to a Uint8Array

Convert a DataView to a string

Convert a Uint8Array to an ArrayBuffer

Convert a Uint8Array to a Blob

Convert a Uint8Array to a Buffer

Convert a Uint8Array to a DataView

Convert a Uint8Array to a ReadableStream

Convert a Uint8Array to a string

Ecosystem

Use Gel with Bun

Use Prisma ORM with Bun

Use Prisma Postgres with Bun

Create a Discord bot

Add Sentry to a Bun app

Use Drizzle ORM with Bun

Build a React app with Bun

Run Bun as a daemon with PM2

Build an app with Nuxt and Bun

Build an app with Qwik and Bun

Build an app with Astro and Bun

Build an app with Remix and Bun

Use TanStack Start with Bun

Run Bun as a daemon with systemd

Build an app with Next.js and Bun

Build an app with SvelteKit and Bun

Build a frontend using Vite and Bun

Build an app with SolidStart and Bun

Use Neon Postgres through Drizzle ORM

Build an HTTP server using Hono and Bun

Use Neon's Serverless Postgres with Bun

Build an HTTP server using Elysia and Bun

Containerize a Bun application with Docker

Build an HTTP server using Express and Bun

Server-side render (SSR) a React component

Build an HTTP server using StricJS and Bun

Read and write data to MongoDB using Mongoose and Bun

HTMLRewriter

Extract links from a webpage using HTMLRewriter

Extract social share images and Open Graph tags

HTTP

Common HTTP server usage

Hot reload an HTTP server

Write a simple HTTP server

Start a cluster of HTTP servers

Configure TLS on an HTTP server

Send an HTTP request using fetch

Proxy HTTP requests using fetch()

Stream a file as an HTTP Response

Upload files via HTTP using FormData

fetch with unix domain sockets in Bun

Streaming HTTP Server with Async Iterators

Server-Sent Events (SSE)

Streaming HTTP Server with Node.js Streams

Package manager

Add a dependency

Add a Git dependency

Add a peer dependency

Add a tarball dependency

Add a trusted dependency

Add an optional dependency

Add a development dependency

Using bun install with Artifactory

Generate a yarn-compatible lockfile

Migrate from npm install to bun install

Configuring a monorepo using workspaces

Install a package under a different name

Configure git to diff Bun's lockb lockfile

Install dependencies with Bun in GitHub Actions

Override the default npm registry for bun install

Using bun install with an Azure Artifacts npm registry

Configure a private registry for an organization scope with bun install

Processes

Read from stdin

Listen for CTRL+C

Listen to OS signals

Spawn a child process

Parse command-line arguments

Read stderr from a child process

Read stdout from a child process

Get the process uptime in nanoseconds

Spawn a child process and communicate using IPC

Reading files

Read a JSON file

Check if a file exists

Read a file to a Buffer

Read a file as a string

Get the MIME type of a file

Read a file to a Uint8Array

Read a file to an ArrayBuffer

Watch a directory for changes

Read a file as a ReadableStream

Runtime

Delete directories

Import a JSON file

Import a TOML file

Import a YAML file

Run a Shell Command

Re-map import paths

Set a time zone in Bun

Set environment variables

Import a HTML file as text

Read environment variables

Build-time constants with --define

Debugging Bun with the web debugger

Install and run Bun in GitHub Actions

Install TypeScript declarations for Bun

Debugging Bun with the VS Code extension

Inspect memory usage using V8 heap snapshots

Define and replace static globals & constants

Codesign a single-file JavaScript executable on macOS

Streams

Convert a ReadableStream to JSON

Convert a Node.js Readable to JSON

Convert a ReadableStream to a Blob

Convert a Node.js Readable to a Blob

Convert a ReadableStream to a Buffer

Convert a ReadableStream to a string

Convert a Node.js Readable to a string

Convert a ReadableStream to a Uint8Array

Convert a ReadableStream to an ArrayBuffer

Convert a Node.js Readable to an Uint8Array

Convert a Node.js Readable to an ArrayBuffer

Convert a ReadableStream to an array of chunks

Test runner

Mock functions in bun test

Spy on methods in bun test

Using Testing Library with Bun

Update snapshots in bun test

Run tests in watch mode with Bun

Use snapshot testing in bun test

Bail early with the Bun test runner

Skip tests with the Bun test runner

Migrate from Jest to Bun's test runner

Run your tests with the Bun test runner

Set the system time in Bun's test runner

Write browser DOM tests with Bun and happy-dom

Set a per-test timeout with the Bun test runner

Mark a test as a "todo" with the Bun test runner

Re-run tests multiple times with the Bun test runner

Set a code coverage threshold with the Bun test runner

Selectively run tests concurrently with glob patterns

Generate code coverage reports with the Bun test runner

import, require, and test Svelte components with bun test

Utilities

Hash a password

Generate a UUID

Escape an HTML string

Get the current Bun version

Encode and decode base64 strings

Check if two objects are deeply equal

Detect when code is executed with Bun

Get the directory of the current file

Get the file name of the current file

Convert a file URL to an absolute path

Compress and decompress data with gzip

Convert an absolute path to a file URL

Get the path to an executable bin file

Sleep for a fixed number of milliseconds

Compress and decompress data with DEFLATE

Get the absolute path of the current file

Check if the current file is the entrypoint

Get the absolute path to the current entrypoint

WebSocket

Build a simple WebSocket server

Enable compression for WebSocket messages

Build a publish-subscribe WebSocket server

Set per-socket contextual data on a WebSocket

Writing files

Write to stdout

Write a Blob to a file

Write a file to stdout

Append content to a file

Write a string to a file

Write a file incrementally

Write a Response to a file

Copy a file to another location

Write a ReadableStream to a file

Deploy on VercelNext