Installation¶

MonoWeaver ships two packages. The API is identical; they differ only in which Mono.Cecil generation they are compiled against.

Package	Mono.Cecil	Target frameworks
`MonoWeaver`	`0.11.2+`	`netstandard2.0`
`MonoWeaver.Cecil10`	`0.10.0` – `0.10.4`	`netstandard2.0`

Which one¶

Check which Cecil generation the game or mod loader already loads, then pick.

Older Unity games, MonoMod 19.x → MonoWeaver.Cecil10. Both packages ship netstandard2.0; Unity's .NET 4.x runtime (2018.1+) provides the netstandard.dll facade, so nothing extra needs to be shipped with your mod.
Everything else → MonoWeaver.

dotnet add package MonoWeaver

dotnet add package MonoWeaver.Cecil10

Two incompatible copies of Cecil is the most common load failure

If your mod loader already ships Mono.Cecil, confirm the version is compatible instead of bringing a second, incompatible copy along with your mod.

Four namespaces, split by responsibility. A normal hook uses all four:

using System;
using System.Linq;
using Mono.Cecil;
using MonoWeaver.Cecil;
using MonoWeaver.CFG;
using MonoWeaver.Patterns;

Namespace	What is in it
`MonoWeaver.Patterns`	`Cil`, `P`, `CilSymbols`, plus match and capture types
`MonoWeaver.Cecil`	`Match`, the rewrite operations, `RewritePlan`
`MonoWeaver.CFG`	`VerifyOptions`, `ILMethodVerifier`
`MonoWeaver.Utils`	The `Verify` extension and Cecil type-comparison helpers

IL2CPP builds: there is no managed IL to read.
Native code, or assemblies obfuscated past what Cecil can parse.
Logic that was inlined into its caller — the original expression may no longer exist there.