What is MCP? Model Context Protocol Explained for Web Developers

#webdev #ai #javascript #tutorial

MCP (Model Context Protocol) lets AI agents call external tools. Think of it as an API that AI models use to access real-world data.

Why It Matters

Without MCP, AI models hallucinate data. With MCP, they query real sources.

User: "Research the electric vehicles market"

Without MCP: ChatGPT makes up numbers
With MCP: Agent queries Wikipedia, Google News, GitHub, arXiv → returns verified data

How It Works

You build an MCP Server — a tool the AI can call
The AI client (Claude, GPT, etc.) connects to your server
When the user asks a question, the AI calls your tool
Your tool returns structured data
The AI uses that data in its response

Simple MCP Server Example

// claude_desktop_config.json
{
  "mcpServers": {
    "market-research": {
      "command": "npx",
      "args": ["mcp-market-research-server"]
    }
  }
}

The AI can now call generate_report(industry, geography) and get real data from 9 sources.

What MCP Servers Can Do

Search the web — query Google, Bing, or custom sources
Access databases — read/write SQL, MongoDB, etc.
Call APIs — GitHub, Slack, Jira, any REST API
Read files — local file system access
Run code — execute scripts and return results

I Built 15 MCP Servers

Server	What It Does
Market Research	Queries 9 APIs, generates reports
Web Search	Real-time web search results
Lead Finder	Find contact info for businesses
SEO Audit	Analyze any website's SEO
Social Media	Bluesky, Reddit, HN data