AutoGen v0.4 is an agent-based AI model launched by Microsoft Research, designed to improve code quality, robustness, generality, and scalability through its asynchronous, event-driven architecture. The model has been comprehensively restructured based on community feedback to support a broader range of agent scenarios, including multi-agent collaboration, distributed computing, and cross-language support. The release of AutoGen v0.4 lays a strong foundation for agent-based AI applications and research, promoting the application and development of AI technologies across various fields.