The Harmony Library allows developers to alter the functionality of C# code by providing an interface to edit the method signature, parameters, return value, and other parts of the method.

Harmony works in the background, meaning that it does not require a separate application to work.

This is a free library that is under an open-source license. The source code is available on GitHub.

There is an online tool that allows developers to test their changes and to send their contributions to the project.

How to install and use Harmony:

Install the Harmony Library into your application. You can use the default installation, or you can also install it into a separate module or even a separate application.

Select the method you want to edit.

You can add, remove, replace, and modify the parameters.

You can also add and remove the return value.