# MirrorNetworking/Mirror

1 Open Source Unity Networking Library

Repository: https://github.com/MirrorNetworking/Mirror
Canonical: https://ross.abutalabs.com/products/mirror
Homepage: https://mirror-networking.com
Language: C#
License: MIT
License Family: permissive
Topics: unity, unet, hlapi, networking, udp, tcp, mirror, telepathy, mmo, mmorpg, ummorpg, mmos, games, libuv, kcp
Last push: 2026-08-22T16:10:56+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 87, longevity 100
- inputs: {"age_days": 2966, "days_push": 11, "days_rel": 11, "gap_med": 1.0, "n_releases_24m": 157}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 6305, forks 869 (observed 2026-08-28T04:09:41.599725+00:00)

## What it is
Mirror is the most popular free open-source networking library for Unity, forked from Unity's deprecated UNET HLAPI and battle-tested since 2014. It provides high-level client-server multiplayer features like spawning, synchronization, RPCs, and pluggable transports (Telepathy, KCP, etc.) for games of all sizes, including MMORPGs.

## Use cases
- add multiplayer to a Unity game
- build an MMORPG in Unity
- synchronize player positions and game state over the network
- replace Unity's deprecated UNET HLAPI
- create a dedicated server for a Unity game
- make a VR multiplayer game like Population: ONE
- choose a transport layer (TCP, UDP, KCP) for Unity networking

## When to choose
- you are building a multiplayer game in Unity and want a free, proven, well-documented solution
- you need high-level networking abstractions (NetworkBehaviour, SyncVars, Commands) rather than raw sockets
- you are migrating away from Unity's UNET or Netcode alternatives
- you want a large community, Discord support, and a track record of shipped Steam games

## When to avoid
- your project is not built on Unity
- you need authoritative server infrastructure with matchmaking, lobbies, and hosting managed for you (consider a backend service)
- you need peer-to-peer or relay networking rather than client-server
- you are doing non-game real-time networking where a general-purpose protocol library fits better

## Facets
- artifact type: library
- maturity: stable
- function: networking, game-engine, websocket, serialization
- domain: gaming-tools, cross-platform
- platform: game-engine, cross-platform
- tags: unity, multiplayer, unet, hlapi, udp, tcp, kcp, telepathy, mmo, game-networking, client-server, sync-vars, game-development, real-time, c#

## Member repositories
- MirrorNetworking/Mirror (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:41.599725+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 2026-08-29T17:46:14.618319+00:00, confidence not recorded.
  - readme: https://github.com/MirrorNetworking/Mirror (fetched 2026-08-28T04:09:41.599725+00:00, sha 2d0fe4f99691)
  - homepage: https://mirror-networking.com (fetched 2026-08-29T08:42:45.362880+00:00, sha a533b29fdbf2)
- Data as of 2026-08-30T08:39:29.467469+00:00.