computer/libs/python/mcp-server

cua-mcp-server

cua-mcp-server is an MCP server for the Computer-Use Agent (CUA). It enables CUA to run through MCP clients such as Claude Desktop and Cursor.

Prerequisites

• Install lume: https://github.com/trycua/cua/blob/main/libs/lume/README.md#install
• Python 3.10+
• pip, venv, setuptools

Install

Download and run the installation script:

curl -fsSL https://raw.githubusercontent.com/trycua/cua/main/libs/python/mcp-server/scripts/install_mcp_server.sh | bash

Add this to your MCP client configuration:

{
  "mcpServers": {
    "cua-agent": {
      "command": "/usr/bin/env",
      "args": [
        "bash",
        "-lc",
        "export CUA_MODEL_NAME='anthropic/claude-3-5-sonnet-20241022'; ~/.cua/start_mcp_server.sh"
      ]
    }
  }
}

Development (run from a local checkout)

Use an absolute path to the repository root in the arguments below.

{
  "mcpServers": {
    "cua-agent": {
      "command": "/usr/bin/env",
      "args": [
        "bash",
        "-lc",
        "export CUA_MODEL_NAME='huggingface-local/ByteDance-Seed/UI-TARS-1.5-7B'; /Users/your-username/Documents/GitHub/cua/libs/python/mcp-server/scripts/start_mcp_server.sh"
      ]
    }
  }
}

Notes:

• Replace /Users/your-username/Documents/GitHub/cua with the absolute path to your clone.
• The script sets PYTHONPATH for local libs and runs the server module.

Quick Start

After configuring your MCP client, restart it and invoke one of these tools:

• Take a screenshot

{
  "tool": "screenshot_cua",
  "args": {}
}

• Run a task

{
  "tool": "run_cua_task",
  "args": { "task": "Open Safari and search for University of Toronto" }
}

Expected results:

• Assistant messages streamed during execution
• A final screenshot image

Documentation

• Installation: https://trycua.com/docs/libraries/mcp-server/installation
• Configuration: https://trycua.com/docs/libraries/mcp-server/configuration
• Usage: https://trycua.com/docs/libraries/mcp-server/usage
• Tools: https://trycua.com/docs/libraries/mcp-server/tools
• Client Integrations: https://trycua.com/docs/libraries/mcp-server/client-integrations
• LLM Integrations: https://trycua.com/docs/libraries/mcp-server/llm-integrations

Troubleshooting

Server reports disconnected in MCP client:

• Use an absolute path in the args command.
• Launch via /usr/bin/env bash -lc so the shell initializes and expands paths.
• Run the script manually to verify:

  /usr/bin/env bash -lc '/Users/your-username/Documents/GitHub/cua/libs/python/mcp-server/scripts/start_mcp_server.sh'
  

pip not found in venv:

python3 -m ensurepip --upgrade
python3 -m pip install -U pip setuptools wheel

Pydantic schema error related to Image:

python3 -m pip install -U "mcp>=1.2.0" "fastmcp>=0.4.7" "pydantic>=2.7,<2.12"

If issues persist, capture logs from your MCP client and the server startup script for diagnosis.