Auto-CO-AFM is an open-source software package for scanning probe microscopes that enables the automatic functionalization of scanning probe tips with carbon monoxide molecules. This enables machine operators to specify the quality of the tip needed utilizing a pre-trained library with off-the-shelf software. From a single image, the software package can determine which molecules on a surface are carbon monoxide, perform the necessary tip functionalization procedures, interface with microscope software to control the tip position, and determine the centeredness of the tip after a successful functionalization. This is of particular interest for atomic force microscopy imaging of molecules on surfaces, where the tip functionalization is a necessary and time consuming step needed for sub-molecular resolution imaging. This package is freely available under the MIT License.