Systems and methods for automatically generating natural language documentation for source code files are provided. An exemplary method includes parsing a source code file to extract a function and generate an abstract syntax tree, generating first natural language documentation for each of a plurality of program statements within the function using a programming language neural network model, generating second natural language documentation for the function as a whole by processing a code snippet of the function using a function documentation neural network model, consolidating the first natural language documentation and the second natural language documentation at a function level, a source file level, and a project level to create consolidated natural language documentation, and summarizing multiple sentences of the consolidated natural language documentation into an abstract summary of the source code file by applying a set of rules.