# EventEmitter2/EventEmitter2

A nodejs event emitter implementation with namespaces, wildcards, TTL, works in the browser

Repository: https://github.com/EventEmitter2/EventEmitter2
Canonical: https://ross.abutalabs.com/products/eventemitter2
Language: JavaScript
License: MIT
License Family: permissive
Topics: event-emitter
Last push: 2024-02-19T07:24:29+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 5574, "days_push": 926, "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 2940, forks 248 (observed 2026-08-28T04:07:30.995610+00:00)

## What it is
EventEmitter2 is a drop-in replacement for Node.js's EventEmitter with extended features like namespaces, wildcards, TTL listeners, and async/promise support. It works in Node.js, browsers, and web workers with strong benchmark performance.

## Use cases
- implement event-driven architecture in nodejs
- use event emitters with namespaces and wildcards
- wait for events with promises
- listen to events in the browser
- replace node's built-in eventemitter with a faster one

## When to choose
- you need namespaced or wildcard event handling
- you want promise-based async event listening
- you need the same emitter API in node and the browser

## When to avoid
- you only need basic events and want zero dependencies
- you need a reactive stream-based event system

## Facets
- artifact type: library
- maturity: stable
- function: concurrency
- domain: developer-tools, web-development
- platform: browser, cross-platform
- tags: event-emitter, namespaces, wildcards, pubsub, javascript, nodejs

## Member repositories
- EventEmitter2/EventEmitter2 (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:30.995610+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 2026-08-30T07:32:57.200477+00:00, confidence not recorded.
  - readme: https://github.com/EventEmitter2/EventEmitter2 (fetched 2026-08-28T04:07:30.995610+00:00, sha abcd3d77bf7c)
- Data as of 2026-08-30T08:39:29.467469+00:00.