What is Model Context Protocol (MCP)?

March 25, 2026 mcp protocol explainer

Model Context Protocol (MCP) is an open standard originally developed by Anthropic that defines how AI assistants connect to external tools and data sources. Think of it as a universal adapter between large language models and the rest of the software world.

The Problem MCP Solves

Before MCP, every AI integration was custom-built. If you wanted Claude or ChatGPT to query your database, read your files, or interact with an API, you had to write bespoke glue code for each combination of model and tool.

MCP standardizes this. An MCP server exposes capabilities — tools, resources, prompts — through a well-defined protocol. Any MCP-compatible client (like Claude Desktop, Cursor, or Windsurf) can connect and use those capabilities without custom integration work.

How It Works

The architecture is simple:

MCP Server — a lightweight process that exposes tools (functions the AI can call), resources (data the AI can read), and prompts (templates for common tasks).
MCP Client — the AI application that connects to servers and makes their capabilities available to the model.
Transport — communication happens over stdio (local) or HTTP with Server-Sent Events (remote).

When you ask an AI assistant to "query my PostgreSQL database," the client discovers the relevant MCP server, sees its available tools (like query or list_tables), and lets the model invoke them.

Why It Matters

MCP is gaining rapid adoption because it brings composability to AI tooling. Instead of monolithic plugins, you get small, focused servers that do one thing well — a PostgreSQL server, a filesystem server, a GitHub server, and so on.

The ecosystem already has over 1,400 servers spanning databases, file systems, AI tools, cloud platforms, and more.

Getting Started

To explore the MCP ecosystem, browse the full catalog of servers or check out the trending servers to see what is growing fastest. If you are building your own MCP server, the official MCP specification and the TypeScript / Python SDKs are the best starting points.