Jupyter MCP Server

# Copyright (c) 2023-2024 Datalayer, Inc. # # BSD 3-Clause License """ Singleton to cache server mode and context managers. """ from jupyter_mcp_server.config import get_config from jupyter_mcp_server.log import logger from jupyter_mcp_server.tools import ServerMode from jupyter_server_api import JupyterServerClient class ServerContext: """Singleton to cache server mode and context managers.""" _instance = None _mode = None _contents_manager = None _kernel_manager = None _kernel_spec_manager = None _session_manager = None _server_client = None _kernel_client = None _initialized = False @classmethod def get_instance(cls): if cls._instance is None: cls._instance = cls() return cls._instance @classmethod def reset(cls): """Reset the singleton instance. Use this when config changes.""" if cls._instance is not None: cls._instance._initialized = False cls._instance._mode = None cls._instance._contents_manager = None cls._instance._kernel_manager = None cls._instance._kernel_spec_manager = None cls._instance._session_manager = None cls._instance._server_client = None cls._instance._kernel_client = None def initialize(self): """Initialize context once.""" if self._initialized: return try: from jupyter_mcp_server.jupyter_extension.context import get_server_context context = get_server_context() if context.is_local_document() and context.get_contents_manager() is not None: self._mode = ServerMode.JUPYTER_SERVER self._contents_manager = context.get_contents_manager() self._kernel_manager = context.get_kernel_manager() self._kernel_spec_manager = context.get_kernel_spec_manager() if hasattr(context, 'get_kernel_spec_manager') else None self._session_manager = context.get_session_manager() if hasattr(context, 'get_session_manager') else None else: self._mode = ServerMode.MCP_SERVER # Initialize HTTP clients for MCP_SERVER mode config = get_config() # Validate that runtime_url is set and not None/empty # Note: String "None" values should have been normalized by start_command() runtime_url = config.runtime_url if not runtime_url or runtime_url in ("None", "none", "null", ""): raise ValueError( f"runtime_url is not configured (current value: {repr(runtime_url)}). " "Please check:\n" "1. RUNTIME_URL environment variable is set correctly (not the string 'None')\n" "2. --runtime-url argument is provided when starting the server\n" "3. The MCP client configuration passes runtime_url correctly" ) logger.info(f"Initializing MCP_SERVER mode with runtime_url: {runtime_url}") self._server_client = JupyterServerClient(base_url=runtime_url, token=config.runtime_token) # kernel_client will be created lazily when needed except (ImportError, Exception) as e: # If not in Jupyter context, use MCP_SERVER mode if not isinstance(e, ValueError): self._mode = ServerMode.MCP_SERVER # Initialize HTTP clients for MCP_SERVER mode config = get_config() # Validate that runtime_url is set and not None/empty # Note: String "None" values should have been normalized by start_command() runtime_url = config.runtime_url if not runtime_url or runtime_url in ("None", "none", "null", ""): raise ValueError( f"runtime_url is not configured (current value: {repr(runtime_url)}). " "Please check:\n" "1. RUNTIME_URL environment variable is set correctly (not the string 'None')\n" "2. --runtime-url argument is provided when starting the server\n" "3. The MCP client configuration passes runtime_url correctly" ) logger.info(f"Initializing MCP_SERVER mode with runtime_url: {runtime_url}") self._server_client = JupyterServerClient(base_url=runtime_url, token=config.runtime_token) else: raise self._initialized = True logger.info(f"Server mode initialized: {self._mode}") @property def mode(self): if not self._initialized: self.initialize() return self._mode @property def contents_manager(self): if not self._initialized: self.initialize() return self._contents_manager @property def kernel_manager(self): if not self._initialized: self.initialize() return self._kernel_manager @property def kernel_spec_manager(self): if not self._initialized: self.initialize() return self._kernel_spec_manager @property def session_manager(self): if not self._initialized: self.initialize() return self._session_manager @property def server_client(self): if not self._initialized: self.initialize() return self._server_client @property def kernel_client(self): if not self._initialized: self.initialize() return self._kernel_client def is_jupyterlab_mode(self) -> bool: """Check if JupyterLab mode is enabled.""" from jupyter_mcp_server.config import get_config config = get_config() return config.is_jupyterlab_mode()