The xcb-util module provides a number of libraries which sit on top of libxcb, the core X protocol library, and some of the extension libraries. These experimental libraries provide convenience functions and interfaces which make the raw X protocol more usable. Some of the libraries also provide client-side code which is not strictly part of the X protocol but which have traditionally been provided by Xlib.

These libraries are currently included, roughly ordered by maturity:

• render-util: Convenience functions for the Render extension.
• aux: Convenient access to connection setup and some core requests.
• atom: Standard core X atom constants and atom caching.
• property: Callback X property-change handling.
• icccm: Both client and window-manager helpers for ICCCM.
• keysyms: Standard X key constants and conversion to/from keycodes.
• event: Callback X event handling.
• image: Port of Xlib's XImage and XShmImage functions.

The online API documentation can be found here, and can be built using doxygen.