MCP Tools

Guard mode acts as a security proxy between an MCP client and an MCP server. It intercepts requests to tools/list, prompts/list, and resources/list to restrict access based on pattern matching.

Note: Guard mode currently only supports STDIO transport (not HTTP).

Pattern Matching: Uses simple glob syntax (*) to match entity names:

• tools:read_* matches all tools starting with read_.
• tools:*file* matches any tool with file in the name.
• prompts:system_* matches all prompts starting with system_.

Usage Patterns:

• Allow-list only: Use --allow 'pattern' to permit only specific entities. If no allow patterns are provided, all are allowed by default (except those explicitly denied).
• Deny-list: Use --deny 'pattern' to block specific entities.
• Combined: You can restrict by both tool type and prompt type.

Integration: To secure a server in an application config (like Claude Desktop), wrap the command with mcp guard:

"command": "mcp",
"args": [
  "guard", "--deny", "tools:write_*,create_*,delete_*",
  "npx", "-y", "@modelcontextprotocol/server-filesystem", "/path/to/dir"
]

Logging: All filtering decisions are logged to ~/.mcpt/logs/guard.log.

You can connect to MCP servers running over HTTP using Server-Sent Events (SSE) transport.

Creating a local SSE server

1. Scaffold a new server: mcp new tool:<name> --transport=sse.
2. Build and start the server using your project's build tools (e.g., npm install && npm run build && npm start).

Connecting to an SSE server

Use mcp tools <URL> to list tools or mcp call <tool_name> --params '<JSON>' <URL> to call a tool on the remote server. The CLI can auto-detect SSE transport from the /sse path.

# Create a new MCP server with SSE transport
mcp new tool:example_tool --transport=sse

# Connect to local SSE server
mcp tools http://localhost:3000/sse

# Call a tool on the local server
mcp call example_tool --params '{"input": "test"}' http://localhost:3000/sse

# Connect to a remote MCP server
mcp tools https://api.example.com/mcp

# Use SSE transport for legacy servers (auto-detected from /sse path)
mcp tools http://legacy-server.com/sse

MCP Tools provides a configuration management system for managing MCP server settings across multiple applications (VS Code, Windsurf, Cursor, Claude Desktop, etc.).

Note: This feature currently only works on macOS.

Configurations are stored in a central registry at $HOME/.mcpt/configs.json. Supported aliases include vscode, vscode-insiders, windsurf, cursor, and claude-desktop.

Common tasks:

• Scan for existing configurations: mcp configs scan
• List all configurations: mcp configs ls
• View a specific config: mcp configs view <alias>
• Set/Update a server: mcp configs set <alias> <name> <command> [args...]
• Remove a server: mcp configs remove <alias> <name>
• Sync/Merge configs: mcp configs sync <alias1> <alias2> --output <alias> --default interactive
• Convert to JSON: Use mcp configs as-json <command_or_url> to generate the JSON structure required by MCP servers.

# Scan for MCP server configurations
mcp configs scan

# Add a server to VS Code
mcp configs set vscode my-server npm run mcp-server

# Add a server to multiple apps at once
mcp configs set vscode,cursor,claude-desktop my-server npm run mcp-server

# Convert a command to MCP JSON format
mcp configs as-json mcp proxy start

The mcp proxy allows you to wrap existing shell scripts as MCP tools.

1. Register: Use mcp proxy tool <name> "<description>" "<parameter_schema>" <path_to_script> to register a script. The parameter schema follows a name:type format (e.g., a:int,b:int).
2. Start: Run mcp proxy start to begin the proxy server.
3. Call: Use mcp call <name> --params '<JSON>' to execute the script through the proxy.

# 1. Create a simple shell script for addition
cat > add.sh << 'EOF'
#!/bin/bash
if [ -z "$a" ] || [ -z "$b" ]; then
  echo "Error: Missing required parameters 'a' or 'b'"
  exit 1
fi
result=$(($a + $b))
echo "The sum of $a and $b is $result"
EOF

# 2. Make it executable
chmod +x add.sh

# 3. Register it as an MCP tool
mcp proxy tool add_numbers "Adds two numbers" "a:int,b:int" ./add.sh

# 4. In one terminal, start the proxy server
mcp proxy start

# 5. In another terminal, you can call it as an MCP tool
mcp call add_numbers --params '{"a":5,"b":3}' --format pretty