Modal MCP Server

Instructions

Deploy a Modal application using the provided parameters.

Args:
    absolute_path_to_app: The absolute path to the Modal application to deploy.

Returns:
    A dictionary containing deployment results.

Raises:
    Exception: If deployment fails for any reason.

Implementation Reference

• src/modal_mcp/server.py:72-94 (handler)

  The main asynchronous handler function for the deploy_modal_app tool. It is registered via the @mcp.tool() decorator and implements the deployment logic by calling run_modal_command to execute 'modal deploy' on the specified app path.

  @mcp.tool()
  async def deploy_modal_app(absolute_path_to_app: str) -> dict[str, Any]:
      """
      Deploy a Modal application using the provided parameters.
  
      Args:
          absolute_path_to_app: The absolute path to the Modal application to deploy.
  
      Returns:
          A dictionary containing deployment results.
  
      Raises:
          Exception: If deployment fails for any reason.
      """
      uv_directory = os.path.dirname(absolute_path_to_app)
      app_name = os.path.basename(absolute_path_to_app)
      try:
          result = run_modal_command(["modal", "deploy", app_name], uv_directory)
          return result
      except Exception as e:
          logger.error(f"Failed to deploy Modal app: {e}")
          raise

• src/modal_mcp/server.py:15-41 (helper)

  Supporting utility function used by deploy_modal_app to run Modal CLI commands via subprocess, handling uv run if directory provided, and returning structured success/error results.

  def run_modal_command(command: list[str], uv_directory: str = None) -> dict[str, Any]:
      """Run a Modal CLI command and return the result"""
      try:
          # uv_directory is necessary for modal deploy, since deploying the app requires the app to use the uv venv
          command = (["uv", "run", f"--directory={uv_directory}"] if uv_directory else []) + command
          logger.info(f"Running command: {' '.join(command)}")
          result = subprocess.run(
              command,
              capture_output=True,
              text=True,
              check=True
          )
          return {
              "success": True,
              "stdout": result.stdout,
              "stderr": result.stderr,
              "command": ' '.join(command)
          }
      except subprocess.CalledProcessError as e:
          return {
              "success": False,
              "error": str(e),
              "stdout": e.stdout,
              "stderr": e.stderr,
              "command": ' '.join(command)
          }