T. O’Neill contributed to the codatio/codat-docs repository by enhancing API documentation and improving diagram clarity over a two-month period. Focusing on Markdown and documentation best practices, O’Neill clarified compatibility for transfer transaction endpoints and embedded direct OpenAPI reference links, streamlining developer access to API details. In addition, O’Neill addressed a diagram parsing bug in the expense transaction synchronization workflow, ensuring accurate rendering and reintroducing status labels to clarify communication flows. The work emphasized accuracy and usability, resulting in clearer onboarding materials and reduced support needs. O’Neill’s contributions demonstrated depth in technical writing and a methodical approach to documentation quality.