Agent2Agent protocol (A2A)
An open protocol for independent agents to discover each other and exchange tasks, messages and results.
The Agent2Agent protocol is an open standard for communication and interoperability between independent AI agent systems that may be built on different frameworks by different vendors. Agents publish agent cards describing their skills, and clients send them messages that create tasks, which progress through a defined lifecycle and produce artifacts. Agents collaborate without sharing their internal plans or tool implementations, so trust has to come from identity, authentication and records rather than inspection.
Agent Minute explains this term on 21 November 2026.
Related terms
Agent cardIn A2A, a published description of an agent's identity, skills, endpoint and authentication requirements.A2A taskThe fundamental unit of work in A2A, with a unique ID and a defined lifecycle of states.Multi-agent systemSeveral agents that divide a task between them and exchange work through a protocol.Agent Payments Protocol (AP2)An open protocol for agent payments built on signed mandates, available as an extension to A2A.