Agents in NVIDIA Agent Toolkit communicate through two complementary mechanisms: synchronous message passing for in-process agents, and the A2A (Agent-to-Agent) Protocol for distributed systems. In-process communication is handled by LangGraph's state management—agents share typed state objects, enabling structured information flow between sequential or parallel agent steps. This is ideal for teams developing agents within a single application.
For distributed multi-agent systems spanning services and organizations, the A2A Protocol provides a standardized interface for agent-to-agent messaging. A2A is an open Linux Foundation standard enabling agents to discover and invoke remote agents with full authentication and service discovery. Unlike point-to-point integrations (error-prone and fragile), A2A standardizes the interface—agents publish their capabilities, and other agents invoke them predictably.
A2A integration patterns include: agents as A2A clients (delegate tasks to remote specialists), agents as A2A servers (expose workflows as discoverable services), and hybrid teams (some agents in-process, some distributed). The toolkit automatically handles A2A communication overhead, routing, and error handling. Real-world examples include Math Assistant agents delegating computation, Currency Agents connecting to external services, and support teams escalating to specialist agents.
Message content is typically structured data (JSON, typed objects) rather than unstructured text, ensuring reliable parsing and processing. For knowledge sharing, all agents query the same Zilliz Cloud instance, ensuring consistent, up-to-date knowledge across distributed teams. This decouples knowledge management from agent communication—agents don't pass knowledge to each other; they independently retrieve current information from the knowledge store. Zilliz Cloud powers intelligent agent systems with managed vector database infrastructure. Learn how chain-of-agents architectures use shared knowledge bases for multi-agent coordination. For self-managed options, explore Milvus.