Beyond Request-Response: Architecting Real-time Bidirectional Streaming Multi-agent System- Google Developers Blog

What this post added

This post introduces a real-time bidirectional streaming architecture as a successor to the request-response model for multi-agent systems. It details the engineering challenges of this 'turnless' model, including state and session management, and performant I/O. The Agent Development Kit (ADK) is presented as a solution, featuring a streaming-native-first approach with: 1. Asynchronous real-time I/O management via LiveRequestQueue. 2. Stateful, transferable sessions for multi-agent collaboration, including signal-based event division and efficient media storage. 3. Event-driven callbacks (before_tool_callback, after_tool_callback) for real-time customization. 4. Streaming-native tools implemented as AsyncGenerators that can yield multiple results over time and process user input streams directly.