# then/promise

Bare bones Promises/A+ implementation

Repository: https://github.com/then/promise
Canonical: https://ross.abutalabs.com/products/promise
Homepage: https://www.promisejs.org
Language: JavaScript
License: MIT
License Family: permissive
Last push: 2023-10-21T03:35:42+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 5001, "days_push": 1047, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2587, forks 306 (observed 2026-08-28T04:07:02.765979+00:00)

## What it is
A bare bones Promises/A+ implementation in JavaScript, serving as a superset of ES6 Promises with minimal necessary extensions. It works on both Node.js and browsers (as a polyfill) and offers optional builds for domains, setImmediate, and ES6 extensions.

## Use cases
- polyfill promises in older browsers or environments without native ES6 promises
- wrap callback-based async APIs into promises
- implement Promises/A+ compliant async control flow in Node.js
- track and log unhandled promise rejections
- use a lightweight promise library with domains support in Node.js

## When to choose
- you need a small, spec-compliant Promises/A+ implementation
- you must support environments lacking native Promise support
- you want a minimal promise library without heavy dependencies

## When to avoid
- your runtime already has native ES6 Promises and you need no extensions
- you need advanced async utilities like cancellation or observables
- you want a library with active ongoing feature development

## Facets
- artifact type: library
- maturity: maintenance
- function: concurrency, developer-tools
- domain: developer-tools, web-development
- platform: browser, cross-platform
- tags: promises, promises-aplus, async, polyfill, es6, javascript, nodejs

## Member repositories
- then/promise (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:02.765979+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 2026-08-30T02:22:25.518570+00:00, confidence not recorded.
  - readme: https://github.com/then/promise (fetched 2026-08-28T04:07:02.765979+00:00, sha e78f89aee668)
  - homepage: https://www.promisejs.org (fetched 2026-08-29T10:05:02.699867+00:00, sha 3c0f3b52b918)
  - registry_npm: https://registry.npmjs.org/promise (fetched 2026-08-29T10:05:02.709627+00:00, sha e49cae223257)
- Data as of 2026-08-30T08:39:29.467469+00:00.