What is the Model Context Protocol (MCP)?
Last verified 2026-09-01The Model Context Protocol (MCP) is an open standard, introduced and open-sourced by Anthropic on 25 November 2024, that connects AI applications and agents to external systems such as tools, data and business apps. It is the context layer of the agentic stack, not a payment protocol: commerce standards like AP2 and ACP build on or extend it. MCP uses JSON-RPC 2.0 over stdio and streamable HTTP, and is licensed under MIT. On 9 December 2025 Anthropic contributed MCP as a founding project of the Agentic AI Foundation, a directed fund under the Linux Foundation, alongside Block's goose and OpenAI's AGENTS.md; more than 10,000 MCP servers had been published by then.
Key facts
| Author / steward | Created by Anthropic; named as a founding technical contribution to the Agentic AI Foundation (Linux Foundation) |
|---|---|
| Announced | 2024-11-25 |
| License | MIT |
| Governance | Introduced by Anthropic; named on 9 December 2025 as a founding technical contribution to the Agentic AI Foundation, a directed fund under the Linux Foundation, alongside Block's goose and OpenAI's AGENTS.md |
| Scope | An open standard that connects AI applications and agents to external systems (tools, data, business apps). It is the context/tool layer, not a payment protocol; commerce protocols such as AP2 and ACP build on or extend it |
| Transport | JSON-RPC 2.0 over stdio and stateless streamable HTTP in specification version 2026-07-28 |
| Payment | None natively; MCP provides the tool and context layer that payment protocols (AP2, ACP, x402) connect to |
| Maturity | stable |
What makes it distinctive
- Introduced and open-sourced by Anthropic on 25 November 2024
- Created by David Soria Parra and Justin Spahr-Summers at Anthropic
- Named as a founding technical contribution to the Agentic AI Foundation (Linux Foundation) on 9 December 2025
- More than 10,000 published MCP servers when the AAIF was announced
- Adopted by Claude, Cursor, Microsoft Copilot, Gemini, VS Code and ChatGPT
- Licensed under MIT
- Specification 2026-07-28 replaces protocol sessions with a stateless request and response core
- The July 2026 release adds header-based routing, cache hints, authorization hardening and a formal extensions framework
- Commerce platforms expose MCP endpoints for agents: Shopify (public MCP endpoint, Jun 2026) and WooCommerce (native MCP, developer preview)
How MCP works
MCP standardizes how an AI application connects to external systems. An MCP server exposes capabilities (tools to call, resources to read, prompts to use) and an MCP client, embedded in the agent or app, consumes them. Communication is JSON-RPC 2.0 over stdio for local servers or streamable HTTP for remote ones. The result: a tool integration is written once and works in any MCP-compatible host, instead of once per assistant.
Specification and governance
Anthropic introduced and open-sourced MCP on 25 November 2024 (MIT license, spec at modelcontextprotocol). On 9 December 2025, Anthropic contributed MCP as a founding project of the Agentic AI Foundation, a directed fund under the Linux Foundation, alongside Block’s goose and OpenAI’s AGENTS.md; more than 10,000 MCP servers had been published by then. The announced governance goal was vendor-neutral stewardship.
How MCP fits the stack
MCP is the context layer everything else plugs into. AP2 is designed as an extension of MCP and A2A; ACP added MCP transport support in its 2026-04-17 version; UCP can serve capabilities over MCP; x402 has MCP integrations; and MPP works against MCP-addressable endpoints. MCP carries no payments itself (AP2 vs MCP).
Limitations and open questions
MCP solves connectivity, not commerce: identity, authorization and payment all live in the layers above. Quality and security of third-party MCP servers vary, which is precisely the gap trust frameworks like TAP and registration programs like Agent Pay target on the commerce side.
Who should care
Developers building agents or exposing services to them: MCP is the de facto integration layer of the agentic stack, with foundation governance and the largest ecosystem (10,000+ servers as of December 2025).
Adoption
- Anthropic: Creator / steward (2024-11-25). source
- Linux Foundation (Agentic AI Foundation): Governance home (2025-12-09). source
- OpenAI: Adopter; AGENTS.md contributor to AAIF formation (2025-12-09). source
- Shopify: Commerce platform (MCP endpoint) (2026-06-17). source
- WooCommerce: Commerce platform (MCP integration) (2026-06-18). source