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MCP Command

The mcp command exposes your CLI tool's functionality to AI agents using the Model Context Protocol (MCP).

Usage

mytool mcp [subcommand] [flags]

Description

Starts an MCP server that allows AI assistants (like Claude or Gemini) to discover and execute your CLI's commands as tools. This enables agentic workflows where an AI can autonomously use your tool to perform tasks.

Subcommands

mcp start

Starts the MCP server over standard I/O.

mytool mcp start [--debug]
Flag Description
--debug Enable debug logging for MCP communication

mcp tools

Exports the tool definitions to a JSON file for inspection.

mytool mcp tools

This generates an mcp-tools.json file in your current directory, showing the JSON schema for each exposed command. This is useful for:

  • Debugging which commands are exposed to AI agents
  • Understanding the expected input/output format
  • Validating tool definitions before deployment

Common Use Cases

  • Integrating your CLI with AI coding assistants (e.g., Cursor, Windsurf).
  • Enabling autonomous agents to perform infrastructure or DevOps tasks.
  • Providing a standard interface for AI-to-tool communication.

Implementation

The MCP command is powered by the ophis library and is automatically wired into the root command registration.

Why Ophis?

GTB uses ophis rather than the official modelcontextprotocol/go-sdk for several key reasons:

  1. Seamless Cobra Integration: Ophis is specifically designed to read Cobra command trees directly. It automatically maps commands to MCP tool definitions and flags to tool parameters, eliminating the need for manual schema duplication.
  2. Small Footprint: It acts as a thin translation layer, providing exactly what is needed for CLI-to-MCP bridging without the overhead of a full protocol framework.
  3. Transitve Compatibility: The official MCP Go SDK is a transitive dependency of Ophis. If direct protocol access is ever needed or if Ophis is abandoned, migrating to the official SDK is straightforward as the protocol layer is already present in the dependency tree.

For detailed integration instructions, see the MCP Server CLI guide.