MCP is an open protocol released as open source by Anthropic in November 2024, enabling AI models (LLMs) to connect with external data sources and tools in a standardized manner. It can be thought of as the HTTP protocol of the AI world.
Core Concept
MCP overcomes the limitation of LLMs being restricted to answering only from trained data, enabling integration with external applications such as fetching the latest information through Google search results or playing music on Spotify. It is based on a client-server architecture and uses a JSON-based format, making it language-agnostic.
Key Components
MCP consists of three core roles:
- MCP Host: AI applications like Claude Desktop and Cursor that manage multiple clients and enforce security policies
- MCP Client: Embedded within the LLM, responsible for communicating with MCP servers
- MCP Server: Acts as a standardized wrapper for specific data sources or tools, performing API calls, providing external data, offering prompt templates, and more
Key Features
Standardized Protocol
Instead of creating separate connectors for each data source, all connections can be managed through a single standard protocol. This eliminates the need for developers to create special interfaces for each model or data source.
Bidirectional Communication
Unlike traditional API approaches, AI models and data sources can continuously exchange information while maintaining a persistent connection. This enables more complex and interactive operations.
Rich Pre-built Integrations
Provides various pre-built server integrations including file systems, databases (PostgreSQL, SQLite), development tools (Git, GitHub, GitLab), and productivity tools (Slack, Google Maps).
How It Works
MCP operates in two flows depending on the request type:
- Response without Tool Calls: For simple summaries, translations, Q&A, etc., the LLM generates responses independently
- Response with Tool Calls: User input → Host receives → LLM determines required tools → Requests to MCP server → Integrates results and responds
Significance
MCP enables AI models to go beyond simply generating text, allowing them to fetch necessary information in real-time and collaborate with other software and data systems. In 2025, OpenAI also adopted this standard, establishing it as an industry standard in the AI field.