What is Model Context Protocol?

The Model Context Protocol (MCP) is an open standard introduced by Anthropic on November 25, 2024 that enables AI assistants to securely connect with external data sources and tools. Think of it as a universal adapter that allows AI models to interact with your databases, APIs, file systems, and other services. Since launch, MCP has been adopted by Anthropic, OpenAI, Microsoft, Google, AWS, and thousands of third-party developers, becoming the de facto standard for AI-to-tool connectivity.

The Problem MCP Solves

Before MCP, connecting AI assistants to external systems required:

• Custom API integrations for each service
• Repeated implementation of similar patterns
• Security concerns with direct API access
• No standardized way to expose data to AI

MCP provides a standardized protocol that solves all these problems.

How MCP Works

MCP follows a client-server architecture:

Component	Role
MCP Host	The AI application (Claude Desktop, Claude Code, ChatGPT, Cursor, VS Code, Windsurf, etc.)
MCP Client	Protocol handler within the host
MCP Server	Your service that exposes tools/resources

┌─────────────┐     ┌────────────┐     ┌─────────────┐
│   Claude    │────▶│ MCP Client │────▶│ MCP Server  │
│  (Host)     │◀────│            │◀────│ (Your Code) │
└─────────────┘     └────────────┘     └─────────────┘

What MCP Servers Can Expose

MCP servers can provide three types of capabilities:

1. Tools - Functions the AI can call (search database, send email)
2. Resources - Data the AI can read (files, database records)
3. Prompts - Reusable prompt templates

Real-World Examples

The official MCP registry and community now host thousands of servers. A few popular ones:

• GitHub MCP Server: Search repos, create issues, manage PRs
• Slack MCP Server: Send messages, search channels
• Postgres MCP Server: Query and update database records
• Filesystem MCP Server: Read/write local files
• Google Drive MCP Server: Read and search Drive documents
• Puppeteer MCP Server: Browser automation for AI agents
• Brave Search MCP Server: Web search as a tool

You can browse the official registry at registry.modelcontextprotocol.io.

Build checkpoint — do this before the next lesson

You don't need code yet, but you DO need to commit to:

1. Which repos will your capstone MCP server expose? Pick 1–3 repos you'd actually want Claude to search/read/file issues in. Can be personal, team, or public — just repos you own.
2. Generate a GitHub Personal Access Token with repo scope at https://github.com/settings/tokens. Save it somewhere secure — you'll paste it into .env at Module 5's capstone.
3. Install Claude Desktop (https://claude.ai/download) if you haven't already. All the hands-on work runs through its MCP connection.

In the next lesson, we'll explore MCP's architecture in detail. :::