Skip to main content

Bun home page

[Runtime

](../../index.md)[Package Manager

](../../pm/cli/install/index.md)[Bundler

](../../bundler/index.md)[Test Runner

](../../test/index.md)[Guides

](../../guides/index.md)[Reference

](https://bun.com/reference)[Blog

](https://bun.com/blog)[Feedback

](../../feedback/index.md)

Bun implements a set of native APIs on the Bun global object and through several built-in modules. These APIs are heavily optimized and represent the canonical “Bun-native” way to implement some common functionality. Bun strives to implement standard Web APIs wherever possible. Bun introduces new APIs primarily for server-side tasks where no standard exists, such as file I/O and starting an HTTP server. In these cases, Bun’s approach still builds atop standard APIs like Blob, URL, and Request.

server.ts

Bun.serve({
  fetch(req: Request) {
    return new Response("Success!");
  },
});

Click the link in the right column to jump to the associated documentation.

Topic

APIs

HTTP Server

Bun.serve

Shell

$

Bundler

Bun.build

File I/O

Bun.file, Bun.write, Bun.stdin, Bun.stdout, Bun.stderr

Child Processes

Bun.spawn, Bun.spawnSync

TCP Sockets

Bun.listen, Bun.connect

UDP Sockets

Bun.udpSocket

WebSockets

new WebSocket() (client), Bun.serve (server)

Transpiler

Bun.Transpiler

Routing

Bun.FileSystemRouter

Streaming HTML

HTMLRewriter

Headless Browser

Bun.WebView

Hashing

Bun.password, Bun.hash, Bun.CryptoHasher, Bun.sha

CSRF Protection

Bun.CSRF.generate, Bun.CSRF.verify

SQLite

bun:sqlite

PostgreSQL Client

Bun.SQL, Bun.sql

Redis (Valkey) Client

Bun.RedisClient, Bun.redis

FFI (Foreign Function Interface)

bun:ffi

DNS

Bun.dns.lookup, Bun.dns.prefetch, Bun.dns.getCacheStats

Testing

bun:test

Workers

new Worker()

Module Loaders

Bun.plugin

Glob

Bun.Glob

Cookies

Bun.Cookie, Bun.CookieMap

Node-API

Node-API

import.meta

import.meta

Utilities

Bun.version, Bun.revision, Bun.env, Bun.main

Sleep & Timing

Bun.sleep(), Bun.sleepSync(), Bun.nanoseconds()

Random & UUID

Bun.randomUUIDv7()

System & Environment

Bun.which()

Comparison & Inspection

Bun.peek(), Bun.deepEquals(), Bun.deepMatch, Bun.inspect()

String & Text Processing

Bun.escapeHTML(), Bun.stringWidth(), Bun.indexOfLine

URL & Path Utilities

Bun.fileURLToPath(), Bun.pathToFileURL()

Compression

Bun.gzipSync(), Bun.gunzipSync(), Bun.deflateSync(), Bun.inflateSync(), Bun.zstdCompressSync(), Bun.zstdDecompressSync(), Bun.zstdCompress(), Bun.zstdDecompress()

Stream Processing

Bun.readableStreamTo*(), Bun.readableStreamToBytes(), Bun.readableStreamToBlob(), Bun.readableStreamToFormData(), Bun.readableStreamToJSON(), Bun.readableStreamToArray()

Memory & Buffer Management

Bun.ArrayBufferSink, Bun.allocUnsafe, Bun.concatArrayBuffers

Module Resolution

Bun.resolveSync()

Parsing & Formatting

Bun.semver, Bun.TOML.parse, Bun.markdown, Bun.color

Low-level / Internals

Bun.mmap, Bun.gc, Bun.generateHeapSnapshot, bun:jsc

Was this page helpful?

Suggest editsRaise issue

[

Globals

Previous

](../globals/index.md)[

Web APIs

Next

](../web-apis/index.md)