✅ Zero-config ESM/TS package builder.

Powered by oxc, rolldown and rolldown-plugin-dts.

The obuild project aims to be the next-generation successor to the current unbuild.

• 👌 Focus on ESM compatibility.
• 🌱 Fresh rewrite with cleanups and removal of legacy features.
• 🚀 Using oxc (for transform) and rolldown (for bundle) for much faster builds!

Some differences are not easy to adopt. Developing as a standalone project allows for faster progress and dogfooding in real projects.

• 📦 obuild
• 🌳 rou3
• 💥 srvx
• 🕊️ unenv
• 🕰️ omnichron
• ⚙️ c12
• [...add yours...]

# bundle
npx obuild ./src/index.ts
# transform
npx obuild ./src/runtime/:./dist/runtime

You can use --dir to set the working directory.

If paths end with /, obuild uses transpile mode using oxc-transform instead of bundle mode with rolldown.

import { build } from "obuild";
await build({
 cwd: ".",
 entries: ["./src/index.ts"],
});

You can use build.config.mjs (or .ts) or pass config to build() function.

import { defineBuildConfig } from "obuild/config";
export default defineBuildConfig({
 entries: [
 {
 type: "bundle",
 input: ["./src/index.ts", "./src/cli.ts"],
 // outDir: "./dist",
 // minify: false,
 // stub: false,
 // rolldown: {}, // https://rolldown.rs/reference/config-options
 // dts: {}, // https://github.com/sxzz/rolldown-plugin-dts#options
 },
 {
 type: "transform",
 input: "./src/runtime",
 outDir: "./dist/runtime",
 // minify: false,
 // stub: false,
 // oxc: {},
 // resolve: {}
 },
 ],
 hooks: {
 // start: (ctx) => {},
 // end: (ctx) => {},
 // entries: (entries, ctx) => {},
 // rolldownConfig: (config, ctx) => {},
 // rolldownOutput: (output, res, ctx) => {},
 },
});

When working on a package locally, it can be tedious to rebuild or run the watch command every time.

You can use stub: true (per entry config) or the --stub CLI flag. In this mode, obuild skips the actual build and instead links the expected dist paths to the source files.

• For bundle entries, .mjs and .d.mts files re-export the source file.
• For transpile entries, src dir is symlinked to dist.

Caveats:

• You need a runtime that natively supports TypeScript. Deno, Bun, Vite, and Node.js (1)
• For transpile mode, you need to configure your bundler to resolve either .ts or .mjs extensions.
• For bundle mode, if you add a new entry or add/remove a default export, you need to run the stub build again.

(1) For Node.js, you have several options:

• Using node --experimental-strip-types (Available in 22.6)
• Using jiti (node --import jiti/register)
• Using oxc-node (node --import @oxc-node/core/register)
• Using unloader (node --import unloader/register)

• unbuild: Stable solution based on rollup and mkdist.
• tsdown: Alternative bundler based on rolldown.

💛 Released under the MIT license.