You ask Claude Code to fetch a website and summarize it. Instead of useful content, you get back an empty <div> and a bunch of script tags. If you've used Claude Code for web scraping for more than a week, you've hit this wall. Here's why it happens and how to fix it in 30 seconds.
Rewritten against the MCP specification (version 2025-06-18) with three new diagrams. The earlier text described components that are not part of the protocol and called Server-Sent Events "in development"; the spec replaced that transport with Streamable HTTP. Every protocol statement below links to the spec, the transcripts come from real runs against ScrapingAnt's server, and every code block is a file that was executed. Code and captured output: scrapingant-examples/examples/what-is-mcp-server.
An MCP server is a program that offers tools, data and prompt templates to an AI assistant through a standard protocol, the Model Context Protocol. The assistant's application (Claude Desktop, Cursor, VS Code, Claude Code) connects to it, asks what it can do, and calls its tools when the model decides they are needed. The server can be a local process on your machine or a remote service such as ScrapingAnt's, which turns "fetch this page" into a tool the assistant can use.