A2A — Agent-to-Agent Protocol
MCP is agent-to-tool. A2A (Agent2Agent) is agent-to-agent — an open protocol for letting opaque agents built on different frameworks collaborate. Released by Google in April 2025, donated to the Linux Foundation in June 2025, reaching v1.0 in April 2026 with 150+ supporters including AWS, Cisco, Microsoft, Salesforce, SAP, and ServiceNow. It absorbed IBM's ACP and added the AP2 payments extension. This lesson walks the Agent Card, Task lifecycle, and the two transport bindings.
This lesson isn’t interactive yet.
It is part of the curriculum and will get the same treatment as Phase 1 — a visual cover, hands-on labs, derivations with numeric checks and a quiz. Until then, the original lesson is the best place to read it:
Part of Phase 13 — Tools & Protocols. Use the previous / next cards below to keep browsing the phase.