Universal Tool Calling Protocol (utcp Client)

UTCP-MCP Bridge

The last MCP server you'll ever need.

A universal, all-in-one MCP server that brings the full power of the Universal Tool Calling Protocol (UTCP) to the MCP ecosystem.

🚀 Quick Start

Add this configuration to your MCP client (Claude Desktop, etc.):

{
  "mcpServers": {
    "utcp": {
      "command": "npx",
      "args": ["@utcp/mcp-bridge"],
      "env": {
        "UTCP_CONFIG_FILE": "/path/to/your/.utcp_config.json"
      }
    }
  }
}

That's it! No installation required. The bridge will automatically:

• Download and run the latest version via npx
• Load your UTCP configuration from the specified path
• Register all your UTCP manuals as MCP tools
• Provide a unified interface to manage your tool ecosystem

🔧 Configuration

Create a .utcp_config.json file to configure your tools and services:

{
    "load_variables_from": [
      {
        "variable_loader_type": "dotenv",
        "env_file_path": ".env"
      }
    ],
    "manual_call_templates": [
      {
          "name": "openlibrary",
          "call_template_type": "http",
          "http_method": "GET", 
          "url": "https://openlibrary.org/static/openapi.json",
          "content_type": "application/json"
      }
    ],
    "post_processing": [
      {
          "tool_post_processor_type": "filter_dict",
          "only_include_keys": ["name", "description"],
          "only_include_tools": ["openlibrary.*"]
      }
    ],
    "tool_repository": {
      "tool_repository_type": "in_memory"
    },
    "tool_search_strategy": {
      "tool_search_strategy_type": "tag_and_description_word_match"
    }
}

Claude Code (CLI)

For Claude Code (the CLI / IDE extension), register the bridge as a user-scoped MCP server:

claude mcp add-json --scope user utcp '{"type":"stdio","command":"npx","args":["@utcp/mcp-bridge"],"env":{"UTCP_CONFIG_FILE":"/absolute/path/to/.utcp_config.json"}}'

Then restart Claude Code. Verify with claude mcp list. Remove with claude mcp remove utcp --scope user.

🧪 Local development against the bridge

If you're hacking on @utcp/sdk or any other typescript-utcp package and want to exercise it through Claude Code, use the dev scripts:

cd utcp-mcp
npm install
npm run dev:register     # builds typescript-utcp packages, overlays each into the bridge's node_modules, builds the bridge, and registers it as 'utcp-dev' in Claude Code
# restart Claude Code

# After every edit:
npm run dev:register     # rebuilds, re-registers; restart Claude Code

# When done:
npm run dev:unregister   # removes the MCP entry and restores registry node_modules

Both scripts are idempotent and never mutate package.json. The overlay strategy avoids npm link, which under modern npm aliases unlink to uninstall --save and would silently strip the dependency.

The script expects the typescript-utcp checkout to live next to this repo (../typescript-utcp). Override with flags if not:

• --lib-dir <path> — point at a different typescript-utcp checkout, or pass none to skip the overlay step entirely (useful when only editing the bridge)
• --name <mcp-name> (default utcp-dev) — useful if you want the dev bridge alongside a published one
• --config <path> (default ./.utcp_config.json) — point at a different UTCP config

🛠️ Available MCP Tools

The bridge exposes these MCP tools for managing your UTCP ecosystem:

• register_manual - Register new UTCP manuals/APIs
• deregister_manual - Remove registered manuals
• call_tool - Execute any registered UTCP tool
• search_tools - Find tools by description
• list_tools - List all registered tool names
• get_required_keys_for_tool - Get required environment variables
• tool_info - Get complete tool information and schema

📁 What is UTCP?

The Universal Tool Calling Protocol (UTCP) allows you to:

• Connect to any API via HTTP, OpenAPI specs, or custom formats
• Use command-line tools with automatic argument parsing
• Process text and files with built-in utilities
• Chain and combine multiple tools seamlessly

With this MCP bridge, all your UTCP tools become available in Claude Desktop and other MCP clients.

🌟 Features

• ✅ Zero installation - Works via npx
• ✅ Universal compatibility - Works with any MCP client
• ✅ Dynamic configuration - Update tools without restarting
• ✅ Environment isolation - Each project can have its own config
• ✅ Comprehensive tool management - Register, search, call, and inspect tools
• ✅ Web interface available - See web_ui_utcp_mcp_bridge/

🐍 Python Version

For Python users, see the standalone Python implementation in python_mcp_bridge/

🌐 Web Interface

For advanced management with a web UI, check out web_ui_utcp_mcp_bridge/

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