What is MCP? The Open Standard Connecting AI to the Real World

5 min read

MCP — the Model Context Protocol — is an open standard published by Anthropic in late 2024. It defines a universal way for AI assistants to connect to external tools, databases, APIs, and services. Think of it as a USB standard, but for AI: any MCP-compatible tool works with any MCP-compatible AI client, without custom glue code.

The problem MCP solves

Before MCP, connecting an AI assistant to your database meant writing a custom plugin for each AI product. Connect it to GitHub and you'd write another. Each integration was bespoke, fragile, and non-transferable. MCP replaces that chaos with a single protocol — one server speaks to all compatible AI clients.

How it works at a high level

An MCP server is a small process that exposes capabilities — called tools — to an AI client. When you ask your AI to query a database, the client calls the database MCP server's tool, gets the result back as structured data, and incorporates that into its response. The server runs locally on your machine by default, so your credentials never leave your environment.

MCP vs. function calling

OpenAI popularized 'function calling' — a way to define JSON schemas that an AI can invoke. MCP builds on that idea but adds a discovery layer: servers declare their tools dynamically, support resources (read-only data endpoints), and use a standardized transport (stdio or HTTP SSE). An MCP server is self-describing; a function-calling integration is not.

Who created MCP?

Anthropic published the MCP specification and reference SDKs (TypeScript and Python) in November 2024. The specification itself is open — any company can implement a client or server. Within months, GitHub, Cloudflare, Notion, and dozens of open-source authors published their own MCP servers.

Who supports MCP today?

As of early 2025, MCP clients include Claude Desktop (macOS/Windows), Cursor, Windsurf, Cline, Continue, and Zed. The ecosystem is growing fast — check the MCP Servers section of this hub for a curated list of available servers.

Frequently Asked Questions

Is MCP only for Claude?

No. MCP is an open standard. While Anthropic created it, any AI client can implement it. Cursor, Windsurf, Cline, and Continue all support MCP alongside (or instead of) Claude.

Do I need to code to use MCP?

For most popular servers, no. You edit a JSON config file to add a server — no programming required. Building your own custom server does require coding (TypeScript or Python).

Is MCP safe?

MCP servers run locally by default. Your credentials stay on your machine. You should still review what permissions a server requests, just as you would with any software.

Is MCP free?

The protocol and most community servers are free and open-source. Some hosted MCP-as-a-service offerings may charge, but self-hosted servers cost nothing beyond any API fees the underlying service charges.

How MCP Works

6 min

MCP Clients Guide

6 min

Getting Started with MCP

8 min

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