Code Auditor: Make your research software ready for publishing

As research software becomes a key output of scientific work, ensuring its quality, transparency, and sustainability is increasingly critical. Following best practices for research software development not only supports reproducibility and openness but also improves interoperability, reuse, and long-term maintainability. However, keeping up with evolving standards and implementing them consistently across projects remains a major challenge for researchers. Code Auditor is an open-source tool designed to help developers evaluate and improve their research software by automatically assessing compliance with recognized best practices. It analyzes various aspects of a software project, such as version control, licensing, documentation, testing, packaging, and citation, and generates comprehensive human- and machine-readable reports in formats including HTML, Markdown, and JSON. The modular architecture combines specialized analysers for individual files and aggregators that synthesize high-level insights. The tool can be run both from the command line and programmatically, supporting integration into existing workflows. Audit results can be compared with reference metadata (e.g., Software Management Plans) or used to guide software templating and publication processes. Developed under the TDCC NES bottleneck project “Enabling Best Practices for Sustainable Software in the Natural and Engineering Sciences” and funded by the Dutch Research Council (NWO), Code Auditor empowers researchers to make their software more robust, FAIR, and ready for publication.