Glossary › A2A
A2A (Agent-to-Agent Protocol)
A protocol for one agent to discover another (via a published "agent card"), delegate a task to it, and receive results. Complements MCP: MCP connects an agent to tools, A2A connects agents to each other. Most systems do not need it until they have more than one independently owned agent.
Where A2A shows up
All matching postsMCP and Agent Protocols: Building and Consuming Tool Servers
The Model Context Protocol is how agents connect to tools, data, and prompts, and every major provider supports it. Build an MCP server in Python, design tools a model will use correctly, connect it to a coding agent, and learn where A2A and the other agent protocols fit.
MCP vs A2A: Which Agent Protocol Do You Need?
MCP connects an agent to tools. A2A connects agents to each other. Most teams need the first and reach for the second too early. A decision guide with the architecture each one implies, the cases where you need both, and the protocols you can safely ignore for now.