# synrc/n2o

⭕ N2O: Distributed WebSocket Application Server ISO 20922

Repository: https://github.com/synrc/n2o
Canonical: https://ross.abutalabs.com/products/n2o
Homepage: https://ws.n2o.dev
Language: Erlang
License: NOASSERTION
License Family: other
Topics: websockets, mqtt, tcp, udp, bert
Last push: 2026-06-04T10:30:12+00:00

## Health v2 (maintenance only)
Score: 61/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 85, release rhythm 8, longevity 100
- inputs: {"age_days": 4905, "days_push": 90, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1341, forks 167 (observed 2026-08-28T04:04:26.188448+00:00)

## What it is
N2O is an embeddable message protocol loop library for WebSocket, HTTP, MQTT, and TCP servers written in Erlang. It provides process management, a virtual nodes ring for request routing, sessions, frame encoding (JSON/BERT/ASN.1), and unified APIs for message queues and caching backends.

## Use cases
- build a real-time websocket chat server in erlang
- run application logic inside an mqtt broker as an emq plugin
- implement rpc over message queue with tcp or udp endpoints
- add websocket push messaging to a cowboy web app
- build iot backends speaking mqtt-sn or coap
- manage distributed processes with a hash ring of virtual nodes

## When to choose
- you are building real-time websocket or mqtt applications on the erlang/otp stack
- you want a tiny (~700 LOC) embeddable protocol loop rather than a heavyweight framework
- you need multi-protocol endpoints (websocket, mqtt, tcp, udp) with one unified message loop
- you want pluggable pubsub backends like gproc or syn and formatters like json or bert

## When to avoid
- your team does not work in erlang or elixir
- you need a conventional request/response web framework with routing, templating, and a large ecosystem
- you require a permissively documented, mainstream license - the license is marked NOASSERTION despite ISC claims
- you need extensive community support, as the project is niche with a small user base

## Facets
- artifact type: framework
- maturity: active
- function: websocket, http-server, message-queue, caching, serialization, rpc, middleware, web-framework
- domain: web-development, backend, iot, microservices
- platform: elixir, windows, self-hosted
- tags: mqtt, tcp, udp, bert, cowboy, emq, pubsub, erlang, protocol-loop, hash-ring, real-time, messaging, linux, macos, web-server

## Member repositories
- synrc/n2o (main) score 61

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:26.188448+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 2026-08-30T04:43:46.193377+00:00, confidence not recorded.
  - readme: https://github.com/synrc/n2o (fetched 2026-08-28T04:04:26.188448+00:00, sha e9619d480473)
  - homepage: https://ws.n2o.dev (fetched 2026-08-29T12:02:40.316153+00:00, sha da78cb3a0603)
- Data as of 2026-08-30T08:39:29.467469+00:00.