Building Multi-Agent Systems the A2A Way: A Hands-On Project with LangGraph
A claims processing system with three services that communicate using Google's A2A (Agent-to-Agent) protocol over JSON-RPC 2.0 : 🔹 A Gateway that handles auth, guardrails, and routing 🔹 A Claims Agent that validates claims and checks for fraud 🔹 A Policy Agent that answers coverage and benefits questions Each agent publishes its own capabilities at a standard /.well-known/agent-card.json endpoint — meaning any A2A-compatible client can discover what it does without me hard-coding anything. Same pattern you'd use to plug into a partner agent in real production. 🛠️ The stack ✅ FastAPI + Pydantic for the JSON-RPC layer ✅ LangGraph for stateful agent reasoning (StateGraph + checkpointing) ✅ MCP (Model Context Protocol) for clean tool abstraction ✅ Anthropic Claude — using Haiku for routing, Sonnet for reasoning, Opus reserved for hard cases ✅ LangSmith for end-to-end observability ✅ Custom guardrails for PII detection and prompt injection 🔍 Why this combo clicks M...