The Secret Life of Bots in Pull Requests: An Empirical Study based on Apache Projects
Chenhao Wei, Lu Xiao, Ting Liao, Yutong Zhao · 2025
Bots are increasingly used in software development for automation and collaboration, particularly in open-source communities like Apache. However, their role in Pull Request (PR) processing is not well understood. This study analyzed 128 Apache Foundation projects with active GitHub repositories, examining 16,989 PRs and 436,057 atomic activities. We identified 29 Bot accounts and 22,208 Bot activities through semi-automated methods. Our analysis addresses four key questions about Bot adoption, usage, behavior, and interaction with developers in PRs. Bots were adopted in 30% of Apache projects, primarily for Build Management, PR Management, and Quality Checking. While commenting is the most common activity (77.1%), most comments (76%) remain technical rather than conversational. Our study highlights the current state of Bot use in PRs and identifies areas for improved automation and intelligence in Bot design.