NodeMCU MCP Service

Implementation Reference

• mcp_server_sdk.js:25-50 (handler)

  Handler for 'list-devices' tool using official MCP SDK. Calls deviceManager.getAllDevices() and formats response as MCP content.

  server.tool(
    "list-devices",
    {}, // No parameters required
    async () => {
      try {
        const devices = deviceManager.getAllDevices();
        return {
          content: [{ 
            type: "text", 
            text: JSON.stringify({
              devices: devices.map(device => ({
                id: device.id,
                name: device.name,
                status: device.status,
                lastSeen: device.lastSeen
              })),
              count: devices.length
            }, null, 2)
          }]
        };
      } catch (error) {
        console.error('Error listing devices:', error);
        throw new Error(`Failed to list devices: ${error.message}`);
      }
    }
  );

• mcp_server.js:119-130 (handler)

  Handler function listDevices() in custom MCP server implementation. Fetches and maps devices from DeviceManager.

  async listDevices() {
    const devices = deviceManager.getAllDevices();
    return {
      devices: devices.map(device => ({
        id: device.id,
        name: device.name,
        status: device.status,
        lastSeen: device.lastSeen
      })),
      count: devices.length
    };
  }

• mcp_server.js:14-17 (schema)

  Schema definition for 'list-devices' tool in custom implementation (no parameters, description provided).

  "list-devices": {
    description: "List all registered NodeMCU devices and their status",
    parameters: {}
  },

• mcp_server.js:13-57 (registration)

  Tool definitions object including registration of 'list-devices' sent during MCP initialization.

  this.toolDefinitions = {
    "list-devices": {
      description: "List all registered NodeMCU devices and their status",
      parameters: {}
    },
    "get-device": {
      description: "Get detailed information about a specific NodeMCU device",
      parameters: {
        deviceId: {
          type: "string",
          description: "The ID of the device to get information about"
        }
      }
    },
    "send-command": {
      description: "Send a command to a NodeMCU device",
      parameters: {
        deviceId: {
          type: "string",
          description: "The ID of the device to send the command to"
        },
        command: {
          type: "string",
          description: "The command to send (restart, update, status, etc.)"
        },
        params: {
          type: "object",
          description: "Optional parameters for the command"
        }
      }
    },
    "update-config": {
      description: "Update the configuration of a NodeMCU device",
      parameters: {
        deviceId: {
          type: "string",
          description: "The ID of the device to update configuration for"
        },
        config: {
          type: "object",
          description: "Configuration parameters to update"
        }
      }
    }
  };

• services/DeviceManager.js:76-78 (helper)

  Core helper method getAllDevices() in DeviceManager that returns all tracked devices.

  getAllDevices() {
    return Array.from(this.devices.values());
  }