MCP (Model Context Protocol) is an open standard that lets AI applications connect to external tools, APIs, and data sources through a single protocol. Think of it as USB-C for AI — instead of building custom integrations for every tool, you build one MCP server and any MCP-compatible AI client can use it.

Anthropic created MCP in November 2024. By 2026, it’s been adopted by OpenAI, Google, Microsoft, and thousands of developers. It now lives under the Linux Foundation.

The problem MCP solves

Before MCP, connecting an AI model to a tool meant writing custom code for each combination:

Claude + Slack = custom integration
Claude + GitHub = custom integration
Claude + Database = custom integration
GPT + Slack = ANOTHER custom integration
GPT + GitHub = ANOTHER custom integration
...

With MCP:

Slack MCP Server → works with Claude, GPT, Gemini, Cursor, VS Code...
GitHub MCP Server → works with Claude, GPT, Gemini, Cursor, VS Code...
Database MCP Server → works with Claude, GPT, Gemini, Cursor, VS Code...

Build the server once, use it everywhere.

How it works

MCP has three components:

MCP Host — The AI application (Claude Desktop, Cursor, VS Code, Claude Code)

MCP Client — Built into the host, handles protocol communication

MCP Server — Your integration. Exposes tools, data, and prompts to the AI.

User → MCP Host (Claude) → MCP Client → MCP Server → Your tool/API/database

Three primitives

MCP servers expose three types of capabilities:

Tools — Actions the AI can take (send a message, create a file, query a database)

Resources — Data the AI can read (files, database records, API responses)

Prompts — Reusable prompt templates with parameters

Who uses MCP?

• Claude Code and Claude Desktop — native MCP support
• Cursor — MCP for tool integrations
• VS Code — via Copilot MCP extensions
• ChatGPT — OpenAI adopted MCP in 2025
• OpenCode — MCP server support
• Thousands of community-built MCP servers

MCP vs A2A

MCP connects AI to tools (vertical). A2A connects AI agents to each other (horizontal). They’re complementary — most production systems use both. See our MCP vs A2A comparison.

Learn more

• MCP Complete Developer Guide
• How to Build an MCP Server (TypeScript)
• MCP Security Risks
• Best MCP Servers for Developers

Related: Future Of Ai Protocols