>> Fay is a complete open-source project that includes the Fay controller and digital human models, allowing for flexible combinations of various application scenarios: virtual anchors, live sales, product guides, voice assistants, remote voice assistants, digital human interactions, digital human interviewers and psychological assessments, Jarvis, and Her. Developers can easily build various types of digital humans or digital assistants using this project. The coupling between different modules in this project is very low, including modules such as sound source, speech recognition, emotion analysis, NLP processing, emotional speech synthesis, speech output, and facial motion output. Each module can be easily replaced.