Complete MCP Server Installation Guide 2026: Configuration for Claude Desktop and Cursor

What is MCP (Explanation for Non-Technical Users)

Model Context Protocol (MCP) is a protocol that allows AI tools (Claude, Cursor, etc.) to "operate" external tools.

Without MCP: AI can only answer questions, unable to access your files, databases, or external services.

With MCP: AI can read and write files, query databases, search the web, and manipulate code repositories.

Simple analogy: MCP is like giving AI a "hand" so it can actually operate a computer, not just a "mouth."

Pre-Installation Preparation

Must have installed:

Node.js 18+ (verify with node -v)

Python 3.9+ (if using Python-based MCP servers)

npm or npx (comes with Node.js)

Optional (recommended):

uv (Python package manager, faster than pip): pip install uv

Configuration for Claude Desktop

Configuration file location:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

Windows: %APPDATA%\Claude\claude_desktop_config.json

Basic configuration example (filesystem + fetch):

json
{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/your_username"]
    },
    "fetch": {
      "command": "uvx",
      "args": ["mcp-server-fetch"]
    }
  }
}

After modification: Fully restart Claude Desktop (not just close the window, but quit the entire app).

Configuration for Cursor

Global configuration file: ~/.cursor/mcp.json

Project-level configuration: Create .cursor/mcp.json in the project root directory.

json
{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "ghp_your_token"
      }
    }
  }
}

Verify Installation Success

Claude Desktop: After restarting, ask in a conversation "What tools can you access?" If it lists MCP tool names, the installation is successful.

Cursor: After configuring .cursor/mcp.json, check the server status in Cursor Settings → MCP (green dot = normal).

5 Recommended MCP Servers for Beginners

filesystem - Read and write files: @modelcontextprotocol/server-filesystem

fetch - Fetch web page content: mcp-server-fetch (requires uvx)

memory - Cross-conversation memory: @modelcontextprotocol/server-memory

brave-search - Web search (requires Brave API key)

github - Git repository operations (requires GitHub token)

Common Error Fixes

Error 1: command not found: npx Fix: Install Node.js and ensure node is in your PATH.

Error 2: MCP server shows red dot / cannot connect Fix: Check if the configuration file JSON format is correct (recommend using a JSON validator).

Error 3: Filesystem MCP but Claude says "Cannot access file" Fix: Ensure the path in the configuration is a correct absolute path and that Claude has read permissions.

Error 4: uvx: command not found Fix: Run pip install uv and ensure uv is in your PATH.