list_service_instances

Instructions

Implementation Reference

• src/mcp_server_nacos/server.py:104-107 (handler)

  Specific handler case for the 'list_service_instances' tool within the MCP server's call_tool function. It retrieves the API URL from the tool class and executes an HTTP GET request via NacosServer.get to list service instances.

  case nacos_tools.NacosToolNames.LIST_INSTANCES:
      url = nacos_tools.NacosListInstances().url
      result = nacos.get(name, url, arguments)
      return [types.TextContent(type="text", text=result)]

• src/mcp_server_nacos/nacos_tools.py:71-92 (schema)

  Tool class defining the schema, input validation, description, and Nacos API endpoint for 'list_service_instances'.

  class NacosListInstances(NacosTool):
      def __init__(self):
          super().__init__(
              name=NacosToolNames.LIST_INSTANCES,
              description="This interface retrieves the list of instances for a specified service.",
              inputSchema={
                  "type": "object",
                  "properties": {
                      "namespaceId": {"type": "string",
                                      "description": "The namespaceId of service, default is `public` if missing"},
                      "groupName": {"type": "string",
                                    "description": "The groupName pattern of service, default is `DEFAULT_GROUP` if missing"},
                      "serviceName": {"type": "string",
                                      "description": "The serviceName pattern of service, required."},
                      "clusterName": {"type": "string",
                                      "description": "The cluster name of instances in service, optional and default is null means match all cluster. If need match multiple cluster, use `,` to split like `cluster1,cluster2`"},
                  },
                  "required": ["serviceName"],
              },
              url="/nacos/v3/admin/ns/instance/list"
          )

• src/mcp_server_nacos/server.py:71-86 (registration)

  Registration of all tools, including NacosListInstances (line 78), in the MCP server's list_tools decorator function.

  @server.list_tools()
  async def handle_list_tools() -> list[types.Tool]:
      """List available tools"""
      return [
          nacos_tools.NacosListNamespacesTool(),
          nacos_tools.NacosListServices(),
          nacos_tools.NacosGetService(),
          nacos_tools.NacosListInstances(),
          nacos_tools.NacosListServiceSubscribers(),
          nacos_tools.NacosListConfigs(),
          nacos_tools.NacosGetConfig(),
          nacos_tools.NacosListConfigHistory(),
          nacos_tools.NacosGetConfigHistory(),
          nacos_tools.NacosListConfigListeners(),
          nacos_tools.NacosListListenedConfigs(),
      ]

• src/mcp_server_nacos/server.py:37-46 (helper)

  NacosServer.get method, which performs the actual HTTP GET request to Nacos API, used by all tool handlers including list_service_instances.

  def get(self, name:str, url: str, params: Any = None) -> str:
      url = f'http://{self.host}:{self.port}{url}'
      logger.debug(f'GET {url} with params {params}')
      result = self._request(url, params=params)
      if result is None:
          return "Unexpected error: None result handled."
      if result.is_success():
          return str(result.data)
      return f'Do {name} failed with message: {result.message}'

• src/mcp_server_nacos/nacos_tools.py:261-273 (helper)

  Enum defining the tool name constant 'list_service_instances' used in schema, handler, and registration.

  class NacosToolNames(str, Enum):
      LIST_NAMESPACES = "list_namespaces",
      LIST_SERVICES = "list_services",
      GET_SERVICE = "get_service",
      LIST_INSTANCES = "list_service_instances",
      LIST_SERVICE_SUBSCRIBERS = "list_service_subscribers",
      LIST_CONFIGS = "list_configs",
      GET_CONFIG = "get_config",
      LIST_CONFIG_HISTORY = "list_config_history",
      GET_CONFIG_HISTORY = "get_config_history",
      LIST_CONFIG_LISTENERS = "list_config_listeners",
      LIST_LISTENED_CONFIGS = "list_listened_configs",