The foundational infrastructure enabling agents to communicate, discover tools, and interoperate
| Protocol | Purpose | Status | Key Link |
|---|---|---|---|
| MCP | LLM ↔ Tool connections | Production (Linux Foundation) | Spec |
| A2A | Agent ↔ Agent communication | v0.3 (Linux Foundation) | Spec |
| x402 | Agent crypto payments | Production (Coinbase) | Docs |
| A2UI | Agent → User interfaces | Early (Google) | Announcement |
| Visa TAP | Agent payment identity | Production | GitHub |
Key Insight: "MCP for tools, A2A for agents, x402 for payments" — The protocols are complementary.
"The USB-C for AI Applications"
| Launched | November 25, 2024 by Anthropic |
| Governance | Donated to Linux Foundation AAIF (Dec 9, 2025) |
| Adoption | 97M+ monthly SDK downloads, 5,800+ servers, 300+ clients |
| Market Projection | $1.2B (2022) → $4.5B (2025) |
| Date | Event |
|---|---|
| Nov 2024 | Launched by Anthropic |
| Mar 2025 | OpenAI adopts MCP |
| May 2025 | Microsoft Build integration |
| May 2025 | Docker MCP Catalog/Toolkit launched |
| Dec 9, 2025 | Donated to Linux Foundation AAIF |