A tiny, portable JS library for parsing and transforming JS/TS/JSX, powered by oxc.

• ⚡ Optimized wasm build in a single JS chunk, zero dependencies
• 🪞 Same API as oxc-parser + oxc-transform
• 🤝 Works in browsers and Node.js
• 💾 Fits on a floppy disk

👉 Try it in the online playground.

import { parseSync, transformSync } from "oxbox";

const { code } = transformSync("input.ts", "const a: number = 1");
const { program } = parseSync("input.ts", "const a: number = 1");

All oxc-parser and oxc-transform exports are available (parse, parseSync, transform, transformSync, isolatedDeclaration, moduleRunnerTransform, ...), so oxbox can be used as a drop-in replacement.

The wasm is decoded, decompressed and instantiated lazily on first call. Use await init() to warm it up ahead of time (required before calling sync APIs in browsers).

Async APIs run on a prewarmed worker pool when SharedArrayBuffer is available (in browsers, the page must be cross-origin isolated); otherwise oxbox runs single-threaded and async APIs run on the calling thread.

The official oxc packages ship the parser and transformer as separate binaries, and since the transformer includes its own parser, much of it is duplicated. They also pull in dozens of platform bindings and a JS runtime (emnapi + napi-rs).

oxbox instead:

• 🔗 Links parser and transformer into one wasm binary, optimized together (LTO)
• ⚡ Enables SIMD (simd128) across the whole build, not just in a few hand-written spots
• 🗜️ Embeds the wasm in the JS bundle, compressed with zopfli (deflate-raw) and base93-encoded
• 🪶 Replaces platform bindings and the emnapi / napi-rs runtime with its own tiny N-API + WASI host that runs in Node.js and browsers
• 🧵 Runs async APIs on a multithreaded, prewarmed worker pool

Compared with the official oxc-transform / oxc-parser wasm and native (napi) bindings.

oxbox ships transform and parser as a single wasm; oxc ships them as two packages (and the wasm bindings share the emnapi / napi-rs runtime).

Published under the MIT license 💛.

Bundles oxc (MIT, VoidZero Inc. & Contributors). The N-API / WASI host (src/napi.ts) is derived from emnapi (MIT, Toyobayashi) and the napi-rs wasm runtime (MIT, LongYinan). See LICENSE for full license texts.