Alpha Vantage Stock Analysis MCP Server

Implementation Reference

• src/index.ts:90-102 (handler)

  MCP tool handler for get-daily-stock-data that invokes getStockData with daily interval and handles response/error formatting.

  async ({ symbol, outputsize = "compact" }) => {
      try {
          const data = await getStockData(symbol, "daily", outputsize);
          return {
              content: [{ type: "text", text: data }]
          };
      } catch (error) {
          return {
              content: [{ type: "text", text: `Error fetching daily stock data: ${error instanceof Error ? error.message : String(error)}` }],
              isError: true
          };
      }
  }

• src/index.ts:86-89 (schema)

  Input schema using Zod validators for the tool parameters: symbol and optional outputsize.

  {
      symbol: z.string().describe("Stock symbol (e.g., IBM, AAPL)"),
      outputsize: z.enum(["compact", "full"]).optional().describe("Amount of data to return (compact: latest 100 data points, full: up to 20 years of data)")
  },

• src/index.ts:84-103 (registration)

  Registration of the get-daily-stock-data tool with schema and handler on the MCP server.

  server.tool(
      "get-daily-stock-data",
      {
          symbol: z.string().describe("Stock symbol (e.g., IBM, AAPL)"),
          outputsize: z.enum(["compact", "full"]).optional().describe("Amount of data to return (compact: latest 100 data points, full: up to 20 years of data)")
      },
      async ({ symbol, outputsize = "compact" }) => {
          try {
              const data = await getStockData(symbol, "daily", outputsize);
              return {
                  content: [{ type: "text", text: data }]
              };
          } catch (error) {
              return {
                  content: [{ type: "text", text: `Error fetching daily stock data: ${error instanceof Error ? error.message : String(error)}` }],
                  isError: true
              };
          }
      }
  );

• src/alphaVantage.ts:21-68 (helper)

  Helper function implementing the core API call to Alpha Vantage for stock data, specifically using TIME_SERIES_DAILY for the 'daily' interval used by the tool, and formatting the response.

  export async function getStockData(symbol: string | string[], interval: string | string[] | 'daily', outputsize: string = 'compact'): Promise<string> {
      try {
          // Ensure parameters are strings, not arrays
          const symbolStr = Array.isArray(symbol) ? symbol[0] : symbol;
          const intervalStr = Array.isArray(interval) ? interval[0] : interval;
          const outputsizeStr = Array.isArray(outputsize) ? outputsize[0] : outputsize;
  
          let url: string;
          let timeSeriesKey: string;
  
          if (intervalStr === 'daily') {
              // Use TIME_SERIES_DAILY endpoint
              url = `${BASE_URL}?function=TIME_SERIES_DAILY&symbol=${symbolStr}&outputsize=${outputsizeStr}&apikey=${API_KEY}`;
              timeSeriesKey = 'Time Series (Daily)';
          } else {
              // Use TIME_SERIES_INTRADAY endpoint
              url = `${BASE_URL}?function=TIME_SERIES_INTRADAY&symbol=${symbolStr}&interval=${intervalStr}&outputsize=${outputsizeStr}&apikey=${API_KEY}`;
              timeSeriesKey = `Time Series (${intervalStr})`;
          }
  
          const response = await axios.get(url);
  
          // Check for error messages from Alpha Vantage
          if (response.data['Error Message']) {
              throw new Error(response.data['Error Message']);
          }
  
          if (response.data['Note']) {
              console.warn('API Usage Note:', response.data['Note']);
          }
  
          // Extract the time series data
          const timeSeries = response.data[timeSeriesKey];
  
          if (!timeSeries) {
              throw new Error('No time series data found in the response');
          }
  
          // Format the data
          const formattedData = formatTimeSeriesData(timeSeries, symbolStr, intervalStr);
          return formattedData;
      } catch (error) {
          if (axios.isAxiosError(error)) {
              throw new Error(`API request failed: ${error.message}`);
          }
          throw error;
      }
  }