The keyboard interfaces and protocols in X

[John Found]

Hi. 

I am trying to create a X client that to communicate to X server by the
raw protocol, not using any libraries, such as XLib or XCB.

While with the graphics part it was simple and straightforward task,
solved by simply following the protocol (The documentation on X11 is
pretty complete and well written) and extensions documentation is
available (although the MIT-SHM documentation on the protocol does not
exists at all), I have stuck with the keyboard part of
the protocol.

The biggest problem is the conversion from the keycodes into the
Unicode characters (of course where it is possible).

Do I need XKEYBOARD extension? On only XINPUT. Or both. The
documentation is complex and poorly written. I have a feeling that part
of it was written not to be useful, but simply because it had to be
written.

So, the question: 

What is the simplest, canonical, expected way to handle the keyboard
events in X protocol in order to obtain the Unicode codes of the
pressed keys? In raw protocol therms. And supporting multiple
languages, of course. 

I understand that some processing on the client side is required, but I
am missing the whole picture of the process.

Best Regards.
John Found