# igrigorik/em-websocket

EventMachine based WebSocket server

Repository: https://github.com/igrigorik/em-websocket
Canonical: https://ross.abutalabs.com/products/em-websocket
Homepage: http://www.igvita.com/2009/12/22/ruby-websockets-tcp-for-the-browser/
Language: Ruby
License: MIT
License Family: permissive
Last push: 2021-11-11T05:02:55+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 6100, "days_push": 1756, "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 1689, forks 188 (observed 2026-08-28T04:05:22.426960+00:00)

## What it is
em-websocket is an async WebSocket server library for Ruby built on EventMachine. It supports all WebSocket protocol drafts in use (75, 76, 1-17, RFC 6455) with ping/pong, close codes, and healthcheck endpoints.

## Use cases
- build a websocket server in ruby
- push real-time messages to browsers
- handle bidirectional client-server communication over websockets
- add live updates to a ruby app
- implement a chat or notification server
- run websockets inside an eventmachine reactor

## When to choose
- you are already using EventMachine in a Ruby app
- you need broad legacy WebSocket draft compatibility
- you want a lightweight, minimal Ruby WebSocket server

## When to avoid
- you use modern async Ruby (Async gem) or non-EventMachine stacks
- you need a full-featured framework with channels/pubsub built in
- the project appears to be in maintenance with the last release in 2021

## Facets
- artifact type: library
- maturity: maintenance
- function: websocket, http-server, networking
- domain: web-development, backend, apis
- platform: ruby, cross-platform
- tags: eventmachine, async, websocket-server, real-time-messaging, real-time

## Member repositories
- igrigorik/em-websocket (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:22.426960+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 2026-08-30T03:38:40.892196+00:00, confidence not recorded.
  - readme: https://github.com/igrigorik/em-websocket (fetched 2026-08-28T04:05:22.426960+00:00, sha 20df4a659dcd)
  - homepage: http://www.igvita.com/2009/12/22/ruby-websockets-tcp-for-the-browser/ (fetched 2026-08-29T11:13:31.308232+00:00, sha 559b57f3ff5d)
  - site_page: https://www.igvita.com/ (fetched 2026-08-29T11:13:31.317933+00:00, sha 461eab8cd7b0)
- Data as of 2026-08-30T08:39:29.467469+00:00.