Model Context Protocol (MCP) - From Anthropic Side Project to Linux Foundation Standard in 13 Months

What MCP Is and Is Not

MCP is a universal context exchange and tool-connection standard - the infrastructure layer on which advertising protocols including AdCP, ARTF, and Agentic Audiences are built. It defines how AI agents connect to external tools, data sources, APIs, and resources. It is not an advertising protocol. It is the plumbing beneath the advertising protocols.

In advertising: MCP is what allows a campaign agent to call a DMP for audience data, retrieve brand guidelines, check compliance rules before bidding, and retain cross-campaign memory - all through one standardised interface without custom integrations per data source.

Specification Milestones

• November 2024 (launch): Basic client-server, tool calling, resource access, prompt templates. Synchronous operations only.
• March 26 2025: OAuth 2.1, Streamable HTTP (replaces HTTP+SSE), JSON-RPC batching, Tool Annotations. OpenAI adopts across all products. Microsoft launches Playwright-MCP.
• June 18 2025: Structured tool outputs, server-initiated user interactions (elicitation), improved security, formal governance model.
• September 2025: MCP Registry preview - public catalog and API for server discovery.
• November 25 2025 (current production): Asynchronous task execution, .well-known server identity discovery, enterprise horizontal scaling improvements, long-running workflow governance.
• December 2025: Donated to Linux Foundation AAIF - vendor-neutral governance.