Building Conversational Commerce with Multi-Agent Swarms on GCP: A Working Prototype

Google Cloud developers built HappyDelivery, a working prototype of conversational commerce using LangGraph, Gemini, FastAPI and Google Cloud, following an earlier three-layer blueprint of Ingress, Memory and Cognition. The Ingress layer validates platform-specific webhook signatures for WhatsApp, RCS, Apple Messages and SMS, normalizes payloads into a common schema and offloads them to Pub/Sub, returning HTTP 200 in roughly 300ms. The post walks through the code, state machine, deterministic financial tools and an automated verification suite.