08 · agent-communication · 13 systems # Agent communication & collaborationProtocols and frameworks for agents that talk to agents. Bridges connect agents to tools; this category connects agents to each other. It splits into open protocols for cross-vendor discovery and messaging (A2A, AGNTCY, ANP, NANDA) and multi-agent frameworks where a supervisor delegates work to specialists through handoffs (CrewAI, Microsoft Agent Framework, LangGraph, MetaGPT, CAMEL). SEC.01 ## Systems in this category [OpenScout / Scout OpenScout · agent-communication OpenScout / Scout is a local-first broker that lets addressable agents (Claude Code, Codex, Cursor) send and ask across harnesses on one mesh. cli/api · local · Free (OSS), local](https://www.agentlist.io/systems/scout) [A2A Protocol A2A Project · agent-communication A2A (Agent2Agent) is the open protocol for cross-vendor agent communication — Google-originated, now governed at the Linux Foundation — standardizing Agent Cards for capability discovery plus task-based messaging between agents. api · local/cloud · Open protocol (free)](https://www.agentlist.io/systems/a2a) [AGNTCY AGNTCY · agent-communication AGNTCY is the Cisco-originated 'Internet of Agents' collective — an open-source stack for agent discovery (directory), secure messaging (SLIM), identity, and observability across vendors. api · local/cloud · Free (OSS, Apache-2.0)](https://www.agentlist.io/systems/agntcy) [Agent Network Protocol Community / OSS · agent-communication Agent Network Protocol (ANP) is an open spec for a decentralized web of agents — DID-based identity, capability description, and peer-to-peer agent messaging without a central directory. api · local/cloud · Open protocol (free)](https://www.agentlist.io/systems/anp) [NANDA NANDA (MIT Media Lab) · agent-communication NANDA is MIT Media Lab's 'Internet of AI Agents' research program — a registry and index layer plus protocols for discovering, verifying, and composing agents at internet scale. api · local/cloud · Free (research project)](https://www.agentlist.io/systems/nanda) [BeeAI IBM · agent-communication BeeAI is IBM's open-source agent platform — run, compose, and observe agents locally or on a cluster, with ACP/A2A-style interop and a web UI for non-technical operators. api/cli · local/cloud · Free (OSS, Apache-2.0)](https://www.agentlist.io/systems/beeai) [CrewAI CrewAI · agent-communication CrewAI is the most widely adopted multi-agent framework: model crews of role-based agents in YAML or Python, run sequential or hierarchical processes, and manage fleets through the CrewAI control plane. api/cli · local/cloud · Free OSS core; CrewAI Enterprise paid (verify)](https://www.agentlist.io/systems/crewai) [Microsoft Agent Framework Microsoft · agent-communication Microsoft Agent Framework is the successor to AutoGen and Semantic Kernel's agent pieces — one OSS framework (Python and .NET) for single agents, multi-agent graphs, and Magentic-style orchestration. api · local/cloud · Free OSS (MIT); Azure hosting via Foundry](https://www.agentlist.io/systems/agent-framework) [LangGraph LangChain · agent-communication LangGraph is LangChain's agent orchestration framework — durable stateful graphs with supervisor and swarm multi-agent patterns, checkpointing, and LangGraph Platform for deployment. api · local/cloud · Free OSS; LangGraph Platform paid tiers](https://www.agentlist.io/systems/langgraph) [MetaGPT DeepWisdom · agent-communication MetaGPT is the multi-agent framework that turns a one-line brief into a simulated software company — PM, architect, and engineer agents handing off artifacts along an assembly line. api/cli · local/cloud · Free OSS; MGX hosted product paid (verify)](https://www.agentlist.io/systems/metagpt) [CAMEL CAMEL-AI · agent-communication CAMEL is the research-rooted multi-agent framework: role-playing agents, agent societies, and toolkits for scaling multi-agent behavior — widely used in academic multi-agent studies. api · local/cloud · Free (OSS, Apache-2.0)](https://www.agentlist.io/systems/camel) [Agency Swarm VRSEN · agent-communication Agency Swarm is VRSEN's framework for building 'agencies' of OpenAI-powered agents — defining agents, their tools, and which agents are allowed to talk to which over an explicit communication-flow graph. api · local/cloud · Free (OSS)](https://www.agentlist.io/systems/agency-swarm) [OpenAI Agents SDK OpenAI · agent-communication The OpenAI Agents SDK is OpenAI's lightweight framework for agentic apps — its handoffs primitive is a first-class agent-to-agent mechanism: one agent transfers the live conversation to a specialist. api · local/cloud · Free (OSS SDK); model usage metered](https://www.agentlist.io/systems/openai-agents-sdk) SEC.02 ## Who it's for Builders composing several agents into one system — a coordinator plus specialists — and teams that need agents from different vendors or runtimes to discover and message each other. SEC.03 ## Tradeoffs Frameworks are production-ready code with strong opinions; cross-vendor protocols are early and still converging (IBM's ACP folded into A2A). Most shipping 'multi-agent' systems today are single-framework orchestration — true agent-to-agent messaging across organizations is emerging. FAQ ## Frequently asked ### What is an agent communication platform? Bridges connect agents to tools; this category connects agents to each other. It splits into open protocols for cross-vendor discovery and messaging (A2A, AGNTCY, ANP, NANDA) and multi-agent frameworks where a supervisor delegates work to specialists through handoffs (CrewAI, Microsoft Agent Framework, LangGraph, MetaGPT, CAMEL). ### Who should use an agent communication platform? Builders composing several agents into one system — a coordinator plus specialists — and teams that need agents from different vendors or runtimes to discover and message each other. ### What are the tradeoffs of agent communication platforms? Frameworks are production-ready code with strong opinions; cross-vendor protocols are early and still converging (IBM's ACP folded into A2A). Most shipping 'multi-agent' systems today are single-framework orchestration — true agent-to-agent messaging across organizations is emerging. ### Which agent communication platforms are in the catalog? 13 as of 2026-09-25: OpenScout / Scout (OpenScout), A2A Protocol (A2A Project), AGNTCY (AGNTCY), Agent Network Protocol (Community / OSS), NANDA (NANDA (MIT Media Lab)), BeeAI (IBM), CrewAI (CrewAI), Microsoft Agent Framework (Microsoft), LangGraph (LangChain), MetaGPT (DeepWisdom), CAMEL (CAMEL-AI), Agency Swarm (VRSEN), OpenAI Agents SDK (OpenAI). ### How is this different from bridges and MCP? Bridges are agent↔tool: MCP gives one agent access to tools and data. Agent communication is agent↔agent: discovery, messaging, and delegation between autonomous systems — often one agent calling another the way it would call a tool. ### Is A2A replacing MCP? No — different layers. MCP connects an agent to tools; A2A connects agents to agents. The emerging pattern is MCP inside the agent for tool calls and A2A between agents for task handoffs. ### Do I need a multi-agent framework to run several agents? No — a queue, broker, or shared channel is enough for simple fan-out. Frameworks like CrewAI, Agent Framework, or LangGraph add role and goal abstractions, handoff logic, shared state, and tracing — which pays off once specialists outnumber the coordinator. Other categories - [01AI IDEs06](https://www.agentlist.io/categories/ai-ide) - [02IDE extensions & copilots10](https://www.agentlist.io/categories/ide-extension) - [03CLI & terminal agents15](https://www.agentlist.io/categories/cli-agent) - [04Cloud & autonomous agents05](https://www.agentlist.io/categories/cloud-agent) - [05Platforms & harness multiplexers01](https://www.agentlist.io/categories/platform) - [06Model routers & gateways02](https://www.agentlist.io/categories/model-router) - [07Bridges, brokers & protocols02](https://www.agentlist.io/categories/bridge) - [09Agent services15](https://www.agentlist.io/categories/agent-services) - [10Personal & always-on agents06](https://www.agentlist.io/categories/personal-agent) - [11AI employees & digital coworkers10](https://www.agentlist.io/categories/digital-employee) - [12On-call & ops agents07](https://www.agentlist.io/categories/ops-agent) - [13Browser & computer-use agents06](https://www.agentlist.io/categories/computer-use) - [14Research & analyst agents07](https://www.agentlist.io/categories/research-agent) - [15Voice & phone agents07](https://www.agentlist.io/categories/voice-agent) Examples: A2A · CrewAI · Microsoft Agent Framework · OpenScout / Scout. Entries are editorial records from seed 2026-09-25, not endorsements. --- Source: [Agent communication & collaboration — 13 compared | agentlist.io](https://www.agentlist.io/categories/agent-communication). This is the public page rendered as Markdown; interactive controls require the website.