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It's only the dreamers who ever move mountains.


Mirror is a high level Networking library for Unity 2019/2020 LTS, compatible with different low level Transports.

Mirror is for indie games & small MMOs, made by the developers of uMMORPG and Cubica.

Mirror is optimized for ease of use & probability of success.

We needed a networking library that allows us to launch our games and survive the next decade.

Mirror is stable & production ready.

Free & Open

Mirror is free & open source!

We need Mirror for our own games, which is why we will never charge anything.

Funded only by Donations from our fantastic community of over 10,000 people.


The Server & Client are ONE project in order to achieve an order of magnitude gain in productivity.

Making multiplayer games this way is fun & easy. Instead of MonoBehaviour, Mirror provides NetworkBehaviour components with:

  • [Server] / [Client] tags for server-only / client-only code
  • [Command] for Client->Server function calls (e.g. UseItem)
  • [ClientRpc] / [TargetRpc] for Server->Client function calls (e.g. AddChatMessage)
  • [SyncVar] / SyncList to automatically synchronize variables from Server->Client

Getting Started

Get Unity 2019 LTS, download Mirror on the Asset Store, 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.

Made with Mirror

Population: ONE Zooba SCP: Secret Laboratory Naïca Online
Laurum Online SamuTale Nimoyd The Wall
Nestables A Glimpse of Luna One More Night Cubica
Inferna NightZ

And many more...

Mirror LTS (Long Term Support)

If you use Mirror in production, consider Mirror LTS!

  • Bug fixes only.
  • Consistent API: update any time, without any breaking features.
  • Lives along side Unity 2019 LTS.
  • Supported from Sept. 2021 to Sept 2022, depending on feedback.

Mirror V46 LTS is available to all GitHub Sponsors.

All sponsors are invited to the Mirror V46 LTS Repository automatically.

Low Level Transports


Development & Contributing

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

Therefore it is of utmost importance for us to follow the KISS principle in order for our games to survive, so that we can still fix networking bugs 10 years from now if needed.

Keeping the next decade in mind, contributing fixes / tests / improvements is highly appreciated while new features have a low probability of being merged.

At this point, what we don't add to Mirror is more important than what we do add to it!

Bug Bounty

A lot of projects use Mirror in production. If you found a critical bug / exploit in Mirror core, please reach out to us in private. Depending on the severity of the exploit, we offer $50 - $500 for now. Rewards based on Mirror's donations, capped at amount of donations we received that month.

Specifically we are looking for:

  • Ways to crash a Mirror server
  • Ways to exploit a Mirror server
  • Ways to leave a Mirror server in undefined state

We are not looking for DOS/DDOS attacks. The exploit should be possible with just a couple of network packets, and it should be reproducible.

Credits / past findings / fixes:

  • 2020, fholm: fuzzing ConnectMessage to stop further connects [#2397]