bunchee

Zero-config bundler for JS/TS packages — use your package.json as the config.

➜~/project$npm install --save-dev bunchee typescript

➜~/project$

{
  "name": "coffee",
  "type": "module",
  "main": "./dist/index.js",
  "scripts": {
    "build": "bunchee"
  }
}

➜~/project$

Exports  File             Size
.        dist/index.js    5.6 kB

# Why bunchee?

- Zero config - package.json as config

- Auto-generates TypeScript declarations

- Supports ESM, CJS, or dual packages

- Tree-shakeable and monorepo friendly

# Perfect for

- npm packages and component libraries

- Node.js tools, CLI apps, and utilities

- Monorepo workspaces with shared packages

# Learn

## Entry & Convention

Files in src/ folder match export names in package.json:

+--------------------------+---------------------+
| File                     | Export Name         |
+--------------------------+---------------------+
| src/index.ts             | "." (default)       |
| src/lite.ts              | "./lite"            |
| src/react/index.ts       | "./react"           |
+--------------------------+---------------------+

## Directives

Bunchee can manage multiple directives such as "use client", "use server", or "use cache" and automatically split your code into different chunks and preserve the directives properly.

## Wildcard Exports

Use wildcard patterns in exports to dynamically export subpaths:

// package.json
{
  "exports": {
    "./features/*": "./dist/features/*.js"
  }
}

// Output:
// "./features/auth" -> "./dist/features/auth.js"
// "./features/user" -> "./dist/features/user.js"

## Native Addon (.node) Support

supports bundling native Node.js addon files (`.node` binaries).

// src/index.js
import addon from './native-addon.node'

// The .node file is copied to dist/ and
// the import is rewritten to load it at runtime

# Latest release — bunchee v7.0.0

- Up to 5.3× faster on a 57-entry build with declarations

- New package lint checks catch publishing mistakes

- ESM-first package preparation with standard exports

Migrating from bunchee 6

Use Node.js 22.12 or newer.
Expect ES2022 output by default; set --target when an older target is required.
Import bunchee's Node.js API with ESM import instead of require().
bunchee prepare now generates ESM-only packages; pass --cjs for dual ESM and CommonJS output.
Replace the removed --prepare build flag with the bunchee prepare command.
TypeScript 7 projects need @typescript/typescript6 for declaration generation.

Complete migration guide · Plain-text docs for agents