MCP (Model Context Protocol) is an open protocol that standardizes how applications provide context to large language models (LLMs). It offers a consistent way to connect AI models to diverse data sources and tools, enabling agents and complex workflows that link models to the outside world.
Model Context Protocol (MCP)
Model Context Protocol (MCP) is an open protocol that standardizes how applications hand context, data, and tools to large language models. Introduced by Anthropic and quickly adopted across the AI ecosystem, it gives an agent a single, predictable way to reach the outside world instead of a different bespoke integration for every source. I think of it as the connective tissue that turns a model into something that can actually do work against my APIs and data.
- Client-server architecture - An MCP host (an AI application) talks to MCP servers that expose capabilities over a defined transport.
- Tools, resources, and prompts - Servers advertise callable tools, readable resources, and reusable prompts in a consistent, discoverable shape.
- Transport-agnostic - The protocol runs over stdio, HTTP, and streaming transports, so a server can live locally or across the network.
- Built on JSON-RPC - Messages use JSON-RPC 2.0, giving MCP a familiar, well-understood request/response foundation.
In practice, MCP is how the agentic turn actually reaches an API. Across API Evangelist I wrap catalog search, governance checks, and data access as MCP servers so an agent can call them the same way it calls anything else, and I lean on OpenAPI as the source of truth that those servers are generated from. Publishing an MCP server is fast becoming a baseline expectation for API providers who want their capabilities to be usable by agents, not just human developers.
Referenced in API Evangelist papers
This standard shows up in my published research. These reports read the machine-readable evidence provider by provider — and put this standard in the context of a real sector.
The State of Telecom APIs
Real provider-published MCP servers exist at six telecom companies; the rest of the sector's apparent MCP coverage is candidate tooling, not product.
The State of US Insurance APIs
Two hosted MCP servers exist in American insurance — one of them lets an agent quote, underwrite and issue a policy.
Referenced on the API Evangelist blog
Where this standard shows up across sixteen years of my writing at apievangelist.com — how it fits into API design, governance, and the agentic turn.
How I Actually Use MCP Across API Evangelist
2026-07-22
Put Governance Where the Agent Can Reach It
2026-07-07
Me Controlling the Protocol (MCP)
2025-03-20
