FastRTC is a Python library that enables developers to build real-time audio/video streaming applications with minimal code. It provides a high-level `Stream` class that integrates with Gradio for automatic UI generation and supports both WebRTC and WebSocket protocols. The library includes built-in handlers for voice activity detection (VAD) via Silero, speech-to-text via Moonshine, text-to-speech via Kokoro/Cartesia, and turn-taking logic. It also offers TURN credential helpers for Cloudflare, Twilio, and Hugging Face. The architecture revolves around defining a handler function that processes media chunks, wrapping it with turn-taking decorators, and creating a Stream object that handles signaling, connection management, and UI rendering. The codebase is actively maintained with frequent commits and an extensive set of demos integrating with various LLMs and AI services.