How I Built 13 MCP Server Integrations for Claude Code (With Source Code)

I've been using Claude Code as my primary development environment for months. Along the way, I built 13 MCP (Model Context Protocol) server integrations that give Claude access to everything from browser automation to payment processing. Here's how MCP works under the hood, and the source code for three of my most useful integrations. What Are MCP Servers? MCP (Model Context Protocol) is an open standard that lets AI assistants call external tools through a unified interface. Instead of the AI guessing at API responses, MCP servers provide real tool execution with real results. Each MCP server: Exposes a set of tools (functions the AI can call) Communicates over stdio or SSE transport Returns structured results the AI can reason about My MCP Architecture { "mcpServers" : { "brave-search" : { "command" : "npx" , "args" : [ "-y" , "@anthropic/mcp-brave-search" ], "env" : { "BRAVE_API_KEY" : "your-key-here" } }, "stripe" : { "command" : "npx" , "args" : [ "-y" , "@anthropic/mcp-stripe" ],