Cannot find a library to deal with git

Question

I would like to create an app to communicate with github in C# code.
After searching some time, I could not find a library to support this.
What I want to do is something like this fake code:

using GitLibrary;
Repository myRepository = new(Repository);
myRepository.URI = "https://github.com/somerepo/reporoot";
myRepository.LoginName = "myLoginName";
myRepository.LoginPassword = "myPassword";
myRepository.Open();
myRepository.Pull("folderA\folderB\fileXYZ");
....
some code to edit file fileXYZ
....
PushResults results = PushFileChanges("fileName");
....
some code to handle errors.
....
myRepository.Close();

Does anybody know if there exists a library to accomplish this (more or less)?
Oh, I recently moved from Visual Studio to Sharpdevelop, so a library that only works with VS is no solution.

Thanks for any suggestions.