Mirror Documentation

File: README.md Copy Chapter

It's only the dreamers who ever move mountains.

Mirror Networking Copy Chapter

The #1 free open source game networking library for Unity, used by over 200 million players.

Powering major hits like Population: ONE and over 1000 Steam Games.

Originally based on UNET: battle tested since 2014 for 10 years and counting!

Mirror is stable, modular & easy to use for all types of games, even small MMORPGs 🎮.

Made in 🇩🇪🇺🇸🇬🇧🇸🇬🇹🇼 with ❤️.

Features Copy Chapter

Mirror comes with a wide variety of features to support all game genres.
Many of our features quickly became the norm across all Unity netcodes!

Architecture Copy Chapter

The Server & Client are ONE project in order to achieve maximum productivity.

Simply use NetworkBehaviour instead of MonoBehaviour.

Making multiplayer games this way is fun & easy:

public class Player : NetworkBehaviour
{
    // Synced automatically
    [SyncVar] public int health = 100;
    
    // Lists, Dictionaries, Sets too
    SyncList inventory = new SyncList();
    
    // Server/Client-only code
    [Server] void LevelUp() {}
    [Client] void Animate() {}
    
    void Update()
    {
        // isServer/isClient for runtime checks
        if (isServer) Heal();
        if (isClient) Move();
    }
    
    // Zero overhead remote calls
    [Command]   void CmdUseItem(int slot) {} // Client to Server
    [ClientRpc] void RpcRespawn() {}         // Server to all Clients
    [TargetRpc] void Hello() {}              // Server to one Client
}

There's also NetworkServer & NetworkClient.
And that's about it 🤩

Free, Open Source & Community Focused Copy Chapter

Mirror is free & open source (MIT Licensed).

🍺 "Free" as in free beer, and freedom to use it any way you like.

• Host Game Servers anywhere!
• Customize anything freely!
• No paywalls, no CCU costs, no strings attached!

🤝 We are a team of professional game developers, who are paid to use Mirror in production. Our incentives will always align with the community, because we are Mirror users just like you!

❤️ Our fantastic community of over 14,000 users contributes feedback & improvements every day. Please join us on our journey, help others, and consider a Donation if you love our work!

The top quote is from Fitzcarraldo, which is quite reminiscent of this project.

Getting Started Copy Chapter

Get Unity 2019 / 2020 / 2021 / 2022 LTS and 6000.1, Download Mirror, open one of the examples & press Play!

Check out our Documentation to learn how it all works.

If you are migrating from UNET, then please check out our Migration Guide.

Guard - Anti Cheat 🔒 Copy Chapter

Guard is a high impact, zero risk anti-cheat solution built specifically for Unity games. Unlike most commercial anti-cheats, Guard is embedded on the source code level and compiles with your project.

Guard is available on the Asset Store and includes a Mirror Integration!

Made with Mirror Copy Chapter

Thousands of Steam Games Copy Section

Mirror is used by thousands of steam games.

[Population: ONE](https://www.populationonevr.com/) Copy Section

The BigBoxVR team started using Mirror in February 2019 for what eventually became one of the most popular Oculus Rift games.

In addition to 24/7 support from the Mirror team, BigBoxVR also hired one of our engineers.

Population: ONE was acquired by Meta in June 2021, and they've just released a new Sandbox addon in 2022!

[Zooba](https://play.google.com/store/apps/details?id=com.wildlife.games.battle.royale.free.zooba&gl=US) Copy Section

Wildlife Studio's hit Zooba made it to rank #5 of the largest battle royal shooters in the U.S. mobile market.

The game has over 100 million downloads on Google Play, with Wildlife Studios as one of the top 10 largest mobile gaming companies in the world.

[Swarm VR](https://www.swarmvrgame.com/) Copy Section

SPIDER-MAN WITH GUNS!

SWARM is a fast-paced, arcade-style grapple shooter, with quick sessions, bright colorful worlds and globally competitive leaderboards that will take you back to the glory days of Arcade Games.

Available for the Meta Quest, made with Mirror.

[Liars Bar](https://store.steampowered.com/app/3097560/Liars_Bar/) Copy Section

With over 20.000 Overwhelmingly Positive reviews on Steam, Liars Bar is one of our largest showcase games of 2024.

This isn't your average pub – it's a den of lies, deception, and mind games. Grab a seat at a table of four and immerse yourself in the ultimate first-person multiplayer online experience where cunning and trickery are the name of the game.

[Castaways](https://www.castaways.com/) Copy Section

Castaways is a sandbox game where you are castaway to a small remote island where you must work with others to survive and build a thriving new civilization.

Castaway runs in the Browser, thanks to Mirror's WebGL support.

[Nimoyd](https://www.nimoyd.com/) Copy Section

Nudge Nudge Games' first title: the colorful, post-apocalyptic open world sandbox game Nimoyd is being developed with Mirror.

Soon to be released for PC & mobile!

[Project Z](https://www.projektzgame.com/) Copy Section

Projekt Z is a first-person coop survival shooter set in a WW2 Zombie scenario on a secret German island. The game focuses on the threat of "Projekt Z", a clandestine program run by the Nazis to turn Zombies, which have been discovered on the island earlier, into weapons to help turn the tide of the war in Nazi Germany's favor.

Soon to be released!

[Unleashed](https://www.unleashedgames.io/) Copy Section

From original devs of World of Warcraft, Kingdoms of Amalur, and EverQuest comes a new family friendly fantasy adventure. Fight against the forces of darkness, explore a world consumed by wild magic, and build a stronghold with your friends to increase your power in a new world.

Lead by industry veterans Brian Birmingham & Irena Pereira, Unleashed is developing their next gen adventure game made with Mirror!

Follow them on X: https://twitter.com/UnleashingGames/

[Dinkum](https://store.steampowered.com/app/1062520/Dinkum/) Copy Section

Set in the Australian Outback, Dinkum is a relaxing farming & survival game. Made by just one developer, Dinkum already reached 1000+ "Overwhelmingly Positive" reviews 1 week after its early access release.

James Bendon initially made the game with UNET, and then switched to Mirror in 2019.

[A Glimpse of Luna](https://www.glimpse-luna.com/) Copy Section

A Glimpse of Luna - a tactical multiplayer card battle game with the most beautiful concept art & soundtrack.

Made with Mirror by two brothers with no prior game development experience.

[Havoc](https://store.steampowered.com/app/2149290/Havoc/) Copy Section

Havoc is a tactical team-based first-person shooter with a fully destructible environment and a unique art style. Havoc has been one of our favorite made-with-Mirror games for a few years now, and we are excited to finally see it up there on Steam.

[Sun Haven](https://store.steampowered.com/app/1432860/Sun_Haven/) Copy Section

Sun Haven - A beautiful human town, a hidden elven village, and a monster city filled with farming, magic, dragons, and adventure.

After their successful Kickstarter, Sun Haven was released on Steam in 2021 and later on ported to Mirror in 2022.

[A Township Tale](https://townshiptale.com/) Copy Section

A Township Tale is an immersive VR experience, where you can build towns and explore worlds with your friends.

Made with our KCP transport, available on the Meta Quest Store with over 6000+ ratings.

[Inferna](https://inferna.net/) Copy Section

One of the first MMORPGs made with Mirror, released in 2019.

An open world experience with over 1000 CCU during its peak, spread across multiple server instances.

[Samutale](https://www.samutale.com/) Copy Section

A sandbox survival samurai MMORPG, originally released in September 2016.

Later on, the Netherlands based Maple Media switched their netcode to Mirror.

[Another Dungeon](https://www.gameduo.net/en/game/ad) Copy Section

Pixel Art Dungeon MMORPG reaching 5000 CCU at peak times.

Originally developed as a single-player idle game, it underwent a transition to an MMORPG three months before release thanks to Mirror!

[Untamed Isles](https://store.steampowered.com/app/1823300/Untamed_Isles/) Copy Section

The turn based, monster taming MMORPG Untamed Isles is currently being developed by Phat Loot Studios.

After their successful Kickstarter, the New Zealand based studio is aiming for a 2022 release date.

[Portals](https://theportal.to/) Copy Section

Animal Crossing meets Yakuza meets Minecraft — a city builder with a multiplayer central hub. Gather, trade and build — all in the browser!

[SCP: Secret Laboratory](https://scpslgame.com/) Copy Section

Northwood Studios' first title: the multiplayer horror game SCP: Secret Laboratory was one of Mirror's early adopters.

Released in December 2017, today it has more than 140,000 reviews on Steam.

[Naïca Online](https://naicaonline.com/) Copy Section

Naïca is a beautiful, free to play 2D pixel art MMORPG.

The France based team was one of Mirror's early adopters, releasing their first public beta in November 2020.

[Laurum Online](https://laurum.online/) Copy Section

Laurum Online - a 2D retro mobile MMORPG with over 500,000 downloads on Google Play.

[Empires Mobile](https://knightempire.online/) Copy Section

Empires Mobile - Retro mobile MMORPG for Android and iOS, reaching 5000 CCU at times. Check out their video for some early MMORPG nostalgia.

[Overpowered](https://overpoweredcardgame.com/) Copy Section

Overwpowered, the exciting new card game that combines strategy, myth, and fun into one riveting web-based experience. Launched in 2023, made with Mirror!

And many more... Copy Section

Modular Transports Copy Chapter

Mirror uses KCP (reliable UDP) by default, but you may use any of our community transports for low level packet sending:

• (built in) KCP: reliable UDP
• (built in) Telepathy: TCP
• (built in) Websockets: Websockets
• Ignorance: ENET UDP
• LiteNetLib UDP
• FizzySteam: SteamNetwork
• FizzyFacepunch: SteamNetwork
• Epic Relay: Epic Online Services
• Bubble: Apple GameCenter
• Light Reflective Mirror: Self-Hosted Relay

Benchmarks Copy Chapter

• [2022] mischa 400-800 CCU tests
• [2021] Jesus' Benchmarks
• [2019] uMMORPG 480 CCU (worst case)

Development & Contributing Copy Chapter

Mirror is used in production by everything from small indie projects to million dollar funded games that will run for a decade or more.

We prefer to work slow & thoroughly in order to not break everyone's games 🐌.

Therefore, we need to KISS 😗.

Information Security

Mirror-Networking follows common information security industry standards & best practices.

Mirror is free open source software (MIT Licensed), with over 80% test coverage. The company is located in Germany. We do not collect any user data, impose no restrictions on users & developers, or rely on any closed source dependencies other than Unity.

This makes Mirror an attractive choice for government agencies and large corporations with strict information security requirements.

Feel free to reach out to business [at] mirror-networking.com if you have any questions, or need to review any of our policies:

• Development best Practices and SDLC.pdf
• Disaster Recovery Procedure.pdf
• Document Retention and Destruction Policy.pdf
• Encryption Policy.pdf
• Information Security Guidelines.pdf
• Privacy Policy
• Security Policy
• Vulnerability Management Policy.pdf

Please reach out if you decide to use Mirror.

We are excited to hear about your project, and happy to help if needed!

Incident Response & Bug Bounty

A lot of projects use Mirror in production. If you found a critical bug / exploit in Mirror core, please follow the steps outlined in our Security Policy.

Credits / past findings / fixes:

• 2020, fholm: fuzzing ConnectMessage to stop further connects [#2397]
• 2023-04-05: IncludeSec: kcp2k UDP spoofing [#3286]
• 2023-06-27: James Frowen: ClientToServer [SyncVar] allocation attacks

Credits & Thanks 🙏

🪞 Alexey Abramychev (UNET)
🪞 Alan
🪞 c6burns
🪞 Coburn
🪞 cooper
🪞 FakeByte
🪞 fholm
🪞 Gabe (BigBoxVR)
🪞 imer
🪞 James Frowen
🪞 JesusLuvsYooh
🪞 Mischa
🪞 Mr. Gadget
🪞 NinjaKickja
🪞 Paul Pacheco
🪞 Sean Riley (UNET)

File: Assets/Mirror/Examples/AdditiveScenes/README.md Copy Chapter

Additive Scenes Example

IMPORTANT: Make sure you have a layer in project settings called Player for this example to work well.

In Build Settings, remove all scenes and add all of the scenes from the Examples\AdditiveScenes\Scenes folder in the following order:

• MainScene
• SubScene

Open the MainScene in the Editor and make sure the Sub Scenes list in the Network scene object contains the SubScene scene. This is already setup by default, but if the MainScene was opened and saved before putting the scenes in the Build Settings list, the Sub Scenes list may be cleared accidentally.

File -> Build and Run

Start up to 3 built instances: These will all be client players.

Press Play in the Editor and click Host (Server + Client) in the HUD

• This will be the host and the 1st player of up to 4. You can also use Server Only if you prefer.

Click Client in the built instances.

• WASDQE keys to move & turn your player capsule.
• There are objects in the corners of the scene hidden by Proximity Checkers.
• The big area in the middle is where the subscene will be loaded when you get near the shelter.
• There are also networked objects inside the subscene, also with Proximity Checkers.
• Since subscenes are only loaded for individual clients, other clients that are outside the middle Zone won't see what those in the subscene can see.
• If you play a built instance as Host or Server and play as client in the editor, you'll see the subscene content load and unload in the hierarchy as you move in and out of the middle Zone.

File: Assets/Mirror/Examples/Basic/README.md Copy Chapter

Basic Example

This is a bare bones example of a running game with Network Manager and UI prefab players:

1. Remove all scenes from Build Settings, then add the Example scene alone.

2. Open the Example scene and build the project.

3. In the editor, click Play, and Server + Client or Server Only...it will be listening on port 7777.

   • If you clicked Host (Server + Client), the host player will appear as Player 00.

4. Run one or more instances (up to 16 total players) of the built application.

5. Click Client on each instance.

6. Now you will see all players in the editor and the clients, all with data being updated and synchronized.

File: Assets/Mirror/Examples/BenchmarkPrediction/Readme.md Copy Chapter

Mirror's PredictedRigidbody is optimized for low end devices / VR.
While not interacting with the object, there's zero overhead!
While interacting, overhead comes from sync & corrections.

This benchmark has predicted objects which are constantly synced & corrected.
=> This is not a real world scenario, it's worst case that we can use for profiling!
=> As a Mirror user you don't need to worry about this demo.

Benchmark Setup

• Unity 2021.3 LTS
• IL2CPP Builds
• M1 Macbook Pro
• vsync disabled in NetworkManagerPredictionBenchmark.cs

Benchmark Results History for 1000 objects without ghosts:

Not Predicted: 1000 FPS Client, 2500 FPS Server
Predicted:
2024-03-13: 500 FPS Client, 1700 FPS Server
2024-03-13: 580 FPS Client, 1700 FPS Server // micro optimizations
2024-03-14: 590 FPS Client, 1700 FPS Server // UpdateGhosting() every 4th frame
2024-03-14: 615 FPS Client, 1700 FPS Server // predictedRigidbodyTransform.GetPositionAndRotation()
2024-03-15: 625 FPS Client, 1700 FPS Server // Vector3.MoveTowardsCustom()
2024-03-18: 628 FPS Client, 1700 FPS Server // removed O(N) insertion from CorrectHistory()
2024-03-28: 800 FPS Client, 1700 FPS Server // FAST mode prediction

File: Assets/Mirror/Examples/BenchmarkStinkySteak/Dependencies/Unity-Simulation-Timer/README.md Copy Chapter

Simulation Timer

An Lightweight Efficient Timer for Unity. Inspired by Photon Fusion TickTimer

Usage/Examples Copy Chapter

Simulation Timer

private SimulationTimer _disableTimer;

private void Start()
{
    _disableTimer = SimulationTimer.CreateFromSeconds(_delay);
}

private void Update()
{
    if(_disableTimer.IsExpired())
    {
        _gameObject.SetActive(false);
        _disableTimer = SimulationTimer.None;
    }
}

Pauseable Simulation Timer

private PauseableSimulationTimer _timer;

public PauseableSimulationTimer Timer => _timer;

private void Start()
{
    _timer = PauseableSimulationTimer.CreateFromSeconds(_delay);
}

public void TogglePause()
{
    if(!_timer.IsPaused)
    {
        _timer.Pause();
        return;
    }

    _timer.Resume();
}

private void Update()
{
    if(_timer.IsExpired())
    {
        _gameObject.SetActive(false);
        _timer = PauseableSimulationTimer.None;
    }
}

Class Reference Copy Chapter

SimulationTimer: Default Timer
PauseableTimer: Pauseable Timer

File: Assets/Mirror/Examples/MultipleAdditiveScenes/README.md Copy Chapter

Multiple Additive Scenes Example

In Build Settings, remove all scenes and add both of the scenes from the Scenes folder in the following order:

• Main
• Game

Open the Main scene in the Editor and make sure the Game Scene field in the MultiScene Network Manager on the Network scene object contains the Game scene. This is already setup by default, but if the Main scene was opened and saved before putting the scenes in the Build Settings list, the Game Scene field may be cleared accidentally.

MultiScene Network Manager Copy Chapter

The MultiScene Network Manager is derived from the base Network Manager and is responsible for additively loading the subscene instances and placing the players in their respective subscene instances and initializing player SyncVars. It has a Game Scene field where the Game subscene is assigned, and an Instances field to set how many instances are loaded on the server.

In this example, the subscene instances are additively loaded on the server with localPhysicsMode = LocalPhysicsMode.Physics3D. Physics subscenes do not auto-simulate, so each scene has a game object with a generic PhysicsSimulator script on it. This script does nothing on the client, only on the server.

Clients only ever have one instance of the subscene additively loaded (without localPhysicsMode), while server has them all. All networked objects have a NetworkSceneChecker component which is what isolates them to their specific subscene.

Playing in the Instances Copy Chapter

File -> Build and Run

Start at least 3 built instances: These will all be client players.

Press Play in the Editor and click Host (Server + Client) in the HUD - This will be the host and the 1st player. You can also use Server Only if you prefer.

Click Client in the built instances.

• WASDQE keys to move & turn your player capsule, Space to jump.

• Colliding with the small colored spheres scores points base on their color.

• Colliding with the larger tumblers sends them rolling around...they're server-side non-kinematic rigidbodies.

• Only scores for the players in the same subscene are shown at the top of the game window.

File: Assets/Mirror/Examples/MultipleMatches/README.md Copy Chapter

MultipleMatches Example

This example demonstrates how to run a large number of non-physics games concurrently in a single game server instance.

This would be most appropriate for Card, Board, Puzzle, and Arcade games where there is no physics involved, just presentation and messaging.

While this example is turn-based, real-time games work just as well.

When a match is started, a MatchController and Player objects are spawned, all with a Network Match Checker component with the same matchId set. Only clients with the same matchID get messages about each others actions and about their own match. They don't receive any data about other matches that may be running concurrently.

File: Assets/Mirror/Examples/Room/README.md Copy Chapter

Room Example

In Build Settings, remove all scenes and add all of the scenes from the Examples\Room\Scenes folder in the following order:

• MirrorRoomOffline
• MirrorRoomGame
• MirrorRoomOnline

If you opened the Offline scene before doing the above steps, you may have to reassign the scenes to the NetworkRoomManagerExt component of the RoomManager scene object.

File -> Build and Run

Start up to 4 built instances: These will all be client players.

Open the Offline scene in the Editor and press Play

Click Host (Server + Client) in the HUD: This will be host and the 5th player. You can also use Server Only if you prefer.

Click Client in the built instances.

Click Ready in each instance, and finally in the Editor (Host).

Click the Start Game button when all players are ready.

You should now be in the Online scene with your players of random color.

WASDQE keys to move & turn your player capsule.
Collide with the spheres to score points.
Lighter colors score higher.

File: Assets/Mirror/Hosting/Edgegap/README.md Copy Chapter

Edgegap Unity plugin for Dedicated Servers quickstart

This plugin has been tested, and supports Unity versions 2021.2+, including all LTS releases, Unity 2023, and Unity 6.

This plugin is intended to help you:

• get started quickly with Dedicated Servers on Edgegap,
• make your server build iteration as fast as possible,
• make multiplayer development 10x easier by removing the need to learn Linux, Docker, or Cloud concepts.

This plugin does not need to be included in your builds, as it's only a development tool and does not have any runtime features.

Install using git (recommended) Copy Chapter

Benefits Copy Section

• Installing our plugin this way will ensure you get the freshest updates the moment they come out, see the update guide.

Caveats Copy Section

• Requirement: functioning git client installed, for example git-scm.

Instructions Copy Section

1. Open your Unity project,
2. Select toolbar option Window -> Package Manager,
3. Click the + icon and select Add package from git URL...,
4. Input the following URL https://github.com/edgegap/edgegap-unity-plugin.git,
5. Click Add and wait for the Unity Package Manager to complete the installation.

Install via ZIP archive Copy Chapter

Benefits Copy Section

• Slightly easier as no git client is required.

Caveats Copy Section

• Installing our plugin this way will require you to manually replace plugin contents if you wish to update it,
• The newtonsoft package (dependency) version required may not be compatible with your project if you're already using an older version of this package.

Instructions Copy Section

1. Select toolbar option Window -> Package Manager,
2. Click the + icon and select Add package by name...,
3. Input the name com.unity.nuget.newtonsoft-json and wait for the Unity Package Manager to complete the installation.,
4. Back to this github project - make sure you're on the main branch,
5. Click <> Code, then Download ZIP,
6. Paste the contents of the unzipped archive in your Assets folder within Unity project root.

Other sources Copy Chapter

The only other official distribution channels for this plugin are:

• Unity Asset Store package
• Mirror Networking source
• Mirror Networking free package
• Mirror Networking LTS package
• Fish Networking source
• Fish Networking free package
• Fish Networking Pro package

Next Steps Copy Chapter

Once you have it, check for Tools -> Edgegap Hosting in Unity's top menu.

Usage requirements Copy Section

To take full advantage of our Unity plugin's build features, you will need to:

• Create an Edgegap Free Tier account,
• Install Docker Desktop (or Docker CLI),
• Install Unity Linux Build Support modules for Unity.

From here, we recommend following our Unity Plugin Guide to get your first dedicated server deployed.

Update the Plugin in Unity Copy Section

If you've installed using git, to update our plugin, locate it in Unity's Package Manager window and click Update. Wait for the process to complete and you're good to go!

If you've installed by copying, you will have to remove the Edgegap folder and paste the newer copy. Your settings are saved in your Unity version, so they shouldn't be lost in this process.

For plugin developers Copy Chapter

This section is only for developers working on this plugin or other plugins interacting / integrating this plugin.

CSharpier code formatter Copy Section

This project uses CSharpier code formatter to ensure consistent and readable formatting, configured in /.config/dotnet-tools.json.

See Editor integration for Visual Studio extensions, optionally configure Reformat with CSharpier on Save under Tools | Options | CSharpier | General. You may also configure running formatting as a pre-commit git hook.

Compiler Symbols Copy Section

If you wish to detect presence of this plugin in the users Unity Editor, you can do so using a compiler directive:

#if EDGEGAP_PLUGIN_SERVERS
{...your code...}
#endif

File: Assets/Mirror/Transports/Edgegap/EdgegapRelay/README.md Copy Chapter

Edgegap Relay for Mirror

Documentation: https://docs.edgegap.com/docs/distributed-relay-manager/

Prerequisites Copy Chapter

• Unity project set up with the Mirror networking library installed
  • Supported Versions: Mirror and Mirror LTS
• EdgegapTransport module downloaded and extracted

Steps Copy Chapter

1. Open your Unity project and navigate to the "Assets" folder.
2. Locate the "Mirror" folder within "Assets" and open it.
3. Within the "Mirror" folder, open the "Transports" folder.
4. Drag and drop the "Unity" folder from the extracted EdgegapTransport files into the "Transports" folder.
5. Open your NetworkManager script in the Unity Editor and navigate to the "Inspector" panel.
6. In the "Inspector" panel, locate the "Network Manager" component and click the "+" button next to the "Transport" property.
7. In the "Add Component" menu that appears, select "Edgegap Transport" to add it to the NetworkManager.
8. Drag the newly added "Edgegap Transport" component into the "Transport" property in the "Inspector" panel.

Notes Copy Chapter

• The EdgegapTransport module is only compatible with Mirror and Mirror LTS versions.