# umijs/father

NPM package development tool

Repository: https://github.com/umijs/father
Canonical: https://ross.abutalabs.com/products/father
Language: TypeScript
License: MIT
License Family: permissive
Last push: 2026-08-13T08:16:24+00:00

## Health v2 (maintenance only)
Score: 96/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 97, release rhythm 93, longevity 100
- inputs: {"age_days": 2651, "days_push": 20, "days_rel": 50, "gap_med": 20, "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 2241, forks 287 (observed 2026-08-28T04:06:29.771771+00:00)

## What it is
father is an NPM package development tool from the UmiJS ecosystem that builds, checks, and helps publish JavaScript/TypeScript packages. It supports both Bundless (ESM/CJS via esbuild, Babel, or SWC) and Bundle (UMD via Webpack) build modes, generates .d.ts types, and offers persistent caching.

## Use cases
- build an npm library to esm and cjs output
- generate umd bundle for a typescript package
- produce d.ts type definitions when publishing a package
- speed up incremental library builds with persistent cache
- prebundle dependencies for a node.js framework
- lint common npm package publishing mistakes
- scaffold jest testing into a library project

## When to choose
- you are developing and publishing an npm package and want an opinionated all-in-one build tool
- you need both module (esm/cjs) and umd outputs from one config
- you want fast incremental builds with persistent caching
- you want automatic TypeScript declaration generation

## When to avoid
- you are building an application rather than a reusable package
- you need full control over a custom webpack/rollup/vite pipeline
- you rely on experimental dependency prebundling in production-critical workflows

## Facets
- artifact type: cli-tool
- maturity: active
- function: build-tool, cli, developer-tools, package-manager
- domain: developer-tools, frontend, web-development
- platform: cli, cross-platform
- tags: npm-package-development, bundless, bundle, esbuild, swc, webpack, typescript-declarations, umi-family, command-line, nodejs

## Member repositories
- umijs/father (main) score 96

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:29.771771+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 2026-08-30T02:44:06.942352+00:00, confidence not recorded.
  - readme: https://github.com/umijs/father (fetched 2026-08-28T04:06:29.771771+00:00, sha e55d0145dbb8)
- Data as of 2026-08-30T08:39:29.467469+00:00.