Google ADK Context Engineering: Five-Layer Architecture Treats Context as First-Class System with Lifecycle and Constraints

Google Developers Blog·medium signal

Google's open-source Agent Development Kit framework implements context engineering as a structured system with five distinct layers: system instructions, tool definitions, conversation history, retrieved knowledge, and user profiles. Each layer has its own lifecycle, optimization constraints, and budget management. The framework makes active context engineering achievable in production multi-agent systems rather than relying on ad-hoc prompt construction.