MCP Glucose Server

Instructions

Implementation Reference

• src/api-client.ts:101-130 (handler)

  Core tool logic: Fetches glucose statistics (count, avg, min, max, unit) from backend API /api/samples/stats endpoint using query params for userId, date range, and BloodGlucose type.

  async getGlucoseStats(params: {
    userId: string;
    startDate?: string;
    endDate?: string;
  }): Promise<GlucoseStats | null> {
    try {
      const queryParams = new URLSearchParams({
        userId: params.userId,
        type: 'BloodGlucose',
      });
  
      if (params.startDate) queryParams.append('startDate', params.startDate);
      if (params.endDate) queryParams.append('endDate', params.endDate);
  
      const response = await this.client.get(`/api/samples/stats?${queryParams}`);
  
      return {
        count: parseInt(response.data.count),
        average: parseFloat(response.data.average),
        min: parseFloat(response.data.min),
        max: parseFloat(response.data.max),
        unit: response.data.unit,
      };
    } catch (error: any) {
      if (error.response?.status === 404) {
        return null;
      }
      throw error;
    }
  }

• src/index.ts:197-223 (handler)

  MCP stdio server tool handler: Dispatches get_glucose_stats calls to api.getGlucoseStats, handles null response, and returns JSON-formatted stats.

  case 'get_glucose_stats': {
    const stats = await api.getGlucoseStats({
      userId,
      startDate: args?.startDate as string | undefined,
      endDate: args?.endDate as string | undefined,
    });
  
    if (!stats) {
      return {
        content: [
          {
            type: 'text',
            text: 'No glucose data found for the specified time range.',
          },
        ],
      };
    }
  
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(stats, null, 2),
        },
      ],
    };
  }

• src/index.ts:72-95 (registration)

  Tool registration in stdio server's tools list: Defines name, description, and inputSchema (userId optional, startDate/endDate optional).

    {
      name: 'get_glucose_stats',
      description:
        'Get glucose statistics (count, average, min, max) for a user within a date range. Useful for understanding glucose trends and patterns.',
      inputSchema: {
        type: 'object',
        properties: {
          userId: {
            type: 'string',
            description: `User identifier. Defaults to ${DEFAULT_USER_ID || 'configured user'} if not specified.`,
          },
          startDate: {
            type: 'string',
            description: 'Start date in ISO 8601 format. Optional.',
          },
          endDate: {
            type: 'string',
            description: 'End date in ISO 8601 format. Optional.',
          },
        },
        required: [],
      },
    },
  ];

• src/api-client.ts:10-16 (schema)

  TypeScript interface defining the output schema for glucose statistics returned by getGlucoseStats.

  export interface GlucoseStats {
    count: number;
    average: number;
    min: number;
    max: number;
    unit: string;
  }

• src/http-server.ts:388-416 (handler)

  HTTP SSE server tool handler: Similar to index.ts, calls api.getGlucoseStats with logging.

  case 'get_glucose_stats': {
    console.log(`📊 Fetching glucose stats for user: ${userId}`);
    const stats = await api.getGlucoseStats({
      userId,
      startDate: args?.startDate as string | undefined,
      endDate: args?.endDate as string | undefined,
    });
  
    if (!stats) {
      return {
        content: [
          {
            type: 'text',
            text: 'No glucose data found for the specified time range.',
          },
        ],
      };
    }
  
    console.log(`✅ Glucose stats: avg ${stats.average} ${stats.unit}`);
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(stats, null, 2),
        },
      ],
    };
  }