claude-code/mcp-server

Claude Code Explorer — MCP Server

A standalone Model Context Protocol (MCP) server that lets any MCP-compatible client explore the Claude Code source code.

What It Does

Exposes 7 tools, 3 resources, and 5 prompts for navigating the ~1,900-file, 512K+ line Claude Code codebase:

Tools

Tool	Description
list_tools	List all 40+ agent tools (BashTool, FileEditTool, etc.)
list_commands	List all 50+ slash commands (/commit, /review, etc.)
get_tool_source	Read a specific tool's implementation
get_command_source	Read a specific command's implementation
read_source_file	Read any file from src/ by relative path
search_source	Regex search across the entire source tree
list_directory	List contents of any directory under src/
get_architecture	Get a full architecture overview

Resources

URI	Description
claude-code://architecture	README / architecture overview
claude-code://tools	Tool registry (JSON)
claude-code://commands	Command registry (JSON)
claude-code://source/{path}	Any source file (template)

Prompts

Prompt	Description
explain_tool	Deep-dive explanation of a specific tool's purpose, schema, permissions, and flow
explain_command	Explanation of a specific slash command's behavior and implementation
architecture_overview	Guided tour of the full Claude Code architecture
how_does_it_work	Explain a feature/subsystem (permissions, MCP, bridge, etc.)
compare_tools	Side-by-side comparison of two tools

Setup

cd mcp-server
npm install
npm run build

Configuration

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "claude-code-explorer": {
      "command": "node",
      "args": ["/absolute/path/to/claude-code/mcp-server/dist/index.js"],
      "env": {
        "CLAUDE_CODE_SRC_ROOT": "/absolute/path/to/claude-code/src"
      }
    }
  }
}

VS Code (GitHub Copilot)

Add to .vscode/mcp.json in your workspace:

{
  "servers": {
    "claude-code-explorer": {
      "type": "stdio",
      "command": "node",
      "args": ["${workspaceFolder}/mcp-server/dist/index.js"],
      "env": {
        "CLAUDE_CODE_SRC_ROOT": "${workspaceFolder}/src"
      }
    }
  }
}

Cursor

Add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "claude-code-explorer": {
      "command": "node",
      "args": ["/absolute/path/to/claude-code/mcp-server/dist/index.js"],
      "env": {
        "CLAUDE_CODE_SRC_ROOT": "/absolute/path/to/claude-code/src"
      }
    }
  }
}

Environment Variables

Variable	Default	Description
CLAUDE_CODE_SRC_ROOT	../src (relative to dist/)	Path to the Claude Code src/ directory

Prompts

The server also exposes prompt templates for guided exploration:

Prompt	Description
explain_tool	Deep-dive explanation of a specific tool (input schema, permissions, execution flow)
explain_command	Explain how a slash command works
architecture_overview	Guided tour of the entire Claude Code architecture
how_does_it_work	Explain a feature or subsystem (e.g. "permission system", "MCP client", "query engine")
compare_tools	Side-by-side comparison of two tools

Example Usage

Once connected, you can ask your AI assistant things like:

• "List all Claude Code tools"
• "Show me the BashTool implementation"
• "Search for how permissions are checked"
• "What files are in the bridge directory?"
• "Read the QueryEngine.ts file, lines 1-100"
• "How does the MCP client connection work?"
• Use the explain_tool prompt with "FileEditTool" to get a full breakdown
• Use how_does_it_work with "bridge" to understand IDE integration

Publishing to MCP Registry

This server is published to the MCP Registry via GitHub Actions. On a tagged release (v*), the workflow:

1. Publishes the npm package to npmjs.org
2. Authenticates with the MCP Registry using GitHub OIDC
3. Publishes the server.json metadata to the registry

To publish manually:

# Install the MCP Publisher CLI
curl -L "https://github.com/modelcontextprotocol/registry/releases/latest/download/mcp-publisher_$(uname -s | tr '[:upper:]' '[:lower:]')_$(uname -m | sed 's/x86_64/amd64/;s/aarch64/arm64/').tar.gz" | tar xz mcp-publisher

# Authenticate (GitHub OAuth)
./mcp-publisher login github

# Publish
cd mcp-server
../mcp-publisher publish

Registry name: io.github.nirholas/claude-code-explorer-mcp

Development

npm install
npm run dev    # Run directly with tsx (no build needed)
npm run build  # Compile TypeScript to dist/
npm start      # Run compiled server