coherence is the fastest and most fun way to make highly performant multiplayer games with Unity. It includes a network engine, a scalable hosting platform, and intuitive Unity tools that make developing a connected game accessible even if you don’t have a networking background.

It is free to use and also offers flexible hosting options. You can:

• Host your game on our coherence servers
• Self-host on a server of your choosing
• Deploy Client-hosted games for free (3rd-party relays supported, like Steam)

Features

• Fast network engine with cloud scaling, state replication, persistence and load balancing.
• Easy to develop, iterate and operate connected games and experiences.
• Make multiplayer games using Windows, Linux or Mac, targeting desktop, console, mobile, VR or the web.
• Visual tools in the Unity SDK help even non-coders create and quickly iterate on a connected game idea.
• Scalable from small games to large virtual worlds running on hundreds of servers.
• Game-service features like user account and key-value stores.
• Easily share WebGL builds for quick testing or game jams, on a coherence-hosted webpage.

Network engine

At the core of coherence lies a fast network engine based on bitstreams and a data-oriented architecture, with numerous optimization techniques like delta compression, quantization and network LOD-ing ("Level of Detail") to minimize bandwidth and maximize performance.

Authority models

The network engine supports multiple authority models:

• Client authority
• Server authority
• Server authority with client prediction
• Authority handover (request, steal)
• Distributed server authority (multiple Simulators with seamless transition)
• Client prediction with rollback
• GGPO-style networking - Experimental

Different authority models can be mixed in the same game!

Persistence

coherence supports persistence out of the box. This means that the state of the world is preserved no matter if clients or simulators are connected to it or not. This way, you can create shared worlds where visitors have a lasting impact.