# frehner/modern-guide-to-packaging-js-library

A guide to help ensure your JavaScript library is the most compatible, fast, and efficient library you can make.

Repository: https://github.com/frehner/modern-guide-to-packaging-js-library
Canonical: https://ross.abutalabs.com/products/modern-guide-to-packaging-js-library
License: GPL-3.0
License Family: copyleft
Topics: javascript, javascript-library, npm
Last push: 2024-01-02T17:01:07+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 1470, "days_push": 974, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1482, forks 41 (observed 2026-08-28T04:04:51.127861+00:00)

## What it is
A community guide with at-a-glance best-practice suggestions for packaging JavaScript libraries for npm, covering module formats (esm, cjs, umd), package. settings, and TypeScript types. It is bundler-agnostic and aimed at library authors rather than application developers.

## Use cases
- how to package a javascript library for npm
- should my library output esm or cjs
- configure package. exports for a js library
- make my npm library tree-shakeable
- set up typescript types correctly for a library
- what module formats should a js library ship
- best practices for publishing an npm package

## When to choose
- you are authoring a JavaScript/TypeScript library to publish on npm
- you want bundler-agnostic packaging advice with explanations of the reasoning
- you need to decide between esm, cjs, and umd outputs
- you want to validate package. and type settings with tools like publint and arethetypeswrong

## When to avoid
- you are packaging an application rather than a library
- you need step-by-step configuration for a specific bundler like webpack, rollup, or vite
- you need a definitive standard rather than suggestions you may deviate from

## Facets
- artifact type: learning-resource
- maturity: active
- function: developer-tools, build-tool, package-manager, documentation
- domain: web-development, frontend, developer-tools, documentation, tutorials
- platform: cross-platform
- tags: javascript-library-packaging, npm, esm, cjs, umd, package-, guide, best-practices, nodejs, web-server

## Member repositories
- frehner/modern-guide-to-packaging-js-library (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:51.127861+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 2026-08-30T04:34:07.224137+00:00, confidence not recorded.
  - readme: https://github.com/frehner/modern-guide-to-packaging-js-library (fetched 2026-08-28T04:04:51.127861+00:00, sha 1de5c3a9a714)
- Data as of 2026-08-30T08:39:29.467469+00:00.