# unjs/unbuild

📦 A unified JavaScript build system

Repository: https://github.com/unjs/unbuild
Canonical: https://ross.abutalabs.com/products/unbuild
Language: TypeScript
License: MIT
License Family: permissive
Topics: universal-javascript
Last push: 2026-08-26T10:34:16+00:00

## Health v2 (maintenance only)
Score: 80/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 43, longevity 100
- inputs: {"age_days": 1974, "days_push": 7, "days_rel": 383, "gap_med": 0, "n_releases_24m": 16}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2725, forks 106 (observed 2026-08-28T04:07:15.790054+00:00)

## What it is
unbuild is a unified JavaScript/TypeScript build system from the unjs ecosystem, built on Rollup, that bundles libraries into CommonJS and ESM formats with generated type declarations. It infers configuration automatically from package. and supports bundleless builds via mkdist and a stub-based development watcher.

## Use cases
- build a TypeScript npm library to ESM and CommonJS
- generate type declarations for my package
- bundle a library without config from package.
- transpile files individually keeping folder structure
- stub dist for fast local development of a linked package
- fail CI on missing or unused dependencies in builds

## When to choose
- you are publishing a JavaScript or TypeScript library to npm
- you want zero-config builds inferred from package.
- you need dual ESM/CJS output with .d.ts generation
- you want fast iteration without watch/rebuild cycles via stub mode

## When to avoid
- you are bundling a full web application rather than a library (use Vite or webpack)
- you want the fastest modern builds and can accept beta software (try obuild)
- you need heavy custom plugin pipelines beyond Rollup's ecosystem

## Facets
- artifact type: cli-tool
- maturity: active
- function: build-tool, compiler, cli, developer-tools
- domain: developer-tools, web-development, frontend, backend
- platform: cli, cross-platform
- tags: bundler, rollup, typescript, library-packaging, unjs, mkdist, esm-cjs, type-declarations, javascript, nodejs

## Member repositories
- unjs/unbuild (main) score 80

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:15.790054+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:14:50.349476+00:00, confidence not recorded.
  - readme: https://github.com/unjs/unbuild (fetched 2026-08-28T04:07:15.790054+00:00, sha 10a016ee2683)
  - registry_npm: https://registry.npmjs.org/unbuild (fetched 2026-08-29T09:58:16.407963+00:00, sha 3eee5ef7d9f2)
- Data as of 2026-08-30T08:39:29.467469+00:00.