How to Design a Production-Grade Multi-Agent Communication System Using LangGraph Structured Message Bus, ACP Logging, and Persistent Shared State Architecture

Abstraction: LangGraph tutorial building ACP message bus with Planner-Executor-Validator agents

Key points:

• System uses ACP-style Pydantic message schema (ACPMessage with sender, receiver, msg_type, content, meta, trace) over a shared BusState rather than agents calling each other directly — enables modularity and traceability
• Three specialized agents: Planner (decomposes goal into steps), Executor (produces structured JSON artifact), Validator (checks correctness and completeness with rule-based checks)
• SQLite-based persistence via LangGraph's SqliteSaver checkpointer provides durable memory across executions; each message appended to a JSONL log file for observability
• Routing logic is dynamic: after each agent runs, route_next() reads active_role from shared state to dispatch to the correct next agent or END
• Communication and orchestration graphs visualized with NetworkX/matplotlib to audit message propagation patterns at runtime

Connections: Langchain · AI Agents · Multi Agent Systems · Agent Orchestration

Source: https://www.marktechpost.com/2026/03/01/how-to-design-a-production-grade-multi-agent-communication-system-using-langgraph-structured-message-bus-acp-logging-and-persistent-shared-state-architecture/