SWE-agent, the first open-source AI programmer launched by Princeton University, is based on GPT-4 technology and can automatically fix bugs in GitHub repositories. Its excellent performance and open-source nature have been highly recognized by the open-source community. It works by interacting with the terminal for code editing, syntax checking, test writing, and execution. Researchers have designed a concise instruction and feedback format, and the workflow is divided into two stages: reasoning and evaluation. It is priced at free.