MonoMod Discord General purpose .NET assembly modding "basework", powered by cecil.

Build and Test

GitHub: All NuGet: Patcher NuGet: Utils NuGet: RuntimeDetour NuGet: HookGen
GitHub releases Core Utils RuntimeDetour HookGen
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MonoMod is a modding "basework" (base tools + framework).
Mods / mod loaders for the following games are already using it in one way or another:

It consists of the following modular components:

  • MonoMod.Patcher: The ahead-of-time MonoMod patcher and relinker.
  • MonoMod.Utils: Utilities and helpers that not only benefit MonoMod, but also mods in general. It contains classes such as PlatformDetection, FastReflectionHelper, DynamicMethodHelper, DynamicMethodDefinition, DynDll and the ModInterop namespace.
  • MonoMod.DebugIL: Enable IL-level debugging of third-party assemblies in Visual Studio / MonoDevelop.
  • MonoMod.Core: The core upon which runtime method detouring is built.
  • MonoMod.RuntimeDetour: A flexible and easily extensible runtime detouring library, supporting x86/x86_64 on .NET Framework, .NET Core, and Mono.
  • MonoMod.RuntimeDetour.HookGen: A utility to generate a "hook helper .dll" for any IL assembly. This allows you to hook methods in runtime mods as if they were events. Built with MonoMod and RuntimeDetour.
  • MonoMod.Backports: A collection of BCL backports, enabling the use of many new language and library features, as far back as .NET Framework 3.5.


  • Cross-version compatibility, even with obfuscated assemblies.
  • Cross-platform compatibility, even if the game uses another engine (f.e. Celeste uses XNA on Windows, FNA on macOS and Linux).
  • Use language features which otherwise wouldn't be supported (f.e. C# 7 in Unity 4.3).
  • Patch on the player's machine with a basic mod installer. No need to pre-patch, no redistribution of game data, no copyright violations.
  • With HookGen, runtime hooks are as simple as On.Namespace.Type.Method += (orig, a, b, c) => { /* ... */ }
  • With HookGen IL, you can manipulate IL at runtime and even inline C# delegate calls between instructions.
  • Modularity allows you to mix and match. Use only what you need!

Special thanks to my patrons on Patreon: