Google Developers Blog introduced HappyDelivery, a functional prototype that implements an earlier blueprint for conversational commerce using LangGraph, Gemini, FastAPI, and Google Cloud. The prototype uses a three-layer decoupled design for message ingress, session and cart persistence, and cognition, with specialized agents, deterministic financial tools, and an automated verification suite. Google also reported multi-agent latency of 2–4 seconds and emphasized that keeping calculations in deterministic tools is necessary for financial accuracy.