jarle/Bun Bun APIs

Bun APIs

Overview of Bun's native APIs available on the Bun global object and built-in modules

Bun implements a set of native APIs on the Bun global object and through a number of 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.

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 | | Hashing | Bun.password, Bun.hash, Bun.CryptoHasher, Bun.sha | | 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 |