We present MonodiKit, a Python library for the analysis and processing of medieval chant documents. While MonodiKit was designed specifically for working with data in the monodi+ data format as edited by the Corpus Monodicum project, its comprehensive set of tools and classes offers a wide range of functionalities, such as parsing and processing of chant documents, exploring their hierarchical structure, managing metadata, generating musical notation, and extracting relevant information. The library thus enables re- searchers and scholars to conduct in-depth computational analyses of the chants, in particular by providing a basic interface to the more common MEI format. This paper introduces the key features of MonodiKit, presents its design and implementation, and presents a case study demonstrating its capabilities as an interface for corpus studies of medieval chant.