get_stock_ohlc

Instructions

Implementation Reference

• server.py:25-29 (handler)

  MCP tool handler for 'get_stock_ohlc', registered via @mcp.tool() decorator. Executes by calling get_stock_data from polygon_api.

  @mcp.tool()
  def get_stock_ohlc(symbol: str, date: str = None) -> str:
      """Get Open, High, Low, Close (OHLC) data for a stock symbol for the last working day or specified date"""
      return get_stock_data(symbol, date)

• polygon_api.py:46-120 (helper)

  Core helper method in PolygonStockAPI class that performs the actual API call to Polygon.io to retrieve OHLC stock data.

  def get_stock_ohlc(self, symbol: str, date: Optional[str] = None) -> Dict:
      """
      Fetch Open, High, Low, Close (OHLC) data for a stock symbol.
      
      Args:
          symbol: Stock symbol (e.g., 'AAPL', 'MSFT', 'GOOGL')
          date: Date in YYYY-MM-DD format. If not provided, uses last working day.
      
      Returns:
          Dictionary containing OHLC data and metadata
      """
      if not date:
          date = self.get_last_working_day()
      
      # Validate symbol format
      symbol = symbol.upper().strip()
      
      # Polygon.io API endpoint for daily bars
      url = f"{self.base_url}/v2/aggs/ticker/{symbol}/prev"
      
      params = {
          "adjusted": "true",
          "apikey": self.api_key
      }
      
      try:
          response = requests.get(url, params=params, timeout=10)
          response.raise_for_status()
          
          data = response.json()
          
          if data.get("status") != "OK":
              return {
                  "error": f"API Error: {data.get('status', 'Unknown error')}",
                  "symbol": symbol,
                  "date": date
              }
          
          results = data.get("results", [])
          if not results:
              return {
                  "error": f"No data found for symbol {symbol}",
                  "symbol": symbol,
                  "date": date
              }
          
          # Extract OHLC data from the first result
          result = results[0]
          
          return {
              "symbol": symbol,
              "date": date,
              "open": result.get("o"),
              "high": result.get("h"),
              "low": result.get("l"),
              "close": result.get("c"),
              "volume": result.get("v"),
              "volume_weighted_average_price": result.get("vw"),
              "number_of_transactions": result.get("n"),
              "status": "success"
          }
          
      except requests.exceptions.RequestException as e:
          return {
              "error": f"Network error: {str(e)}",
              "symbol": symbol,
              "date": date
          }
      except Exception as e:
          return {
              "error": f"Unexpected error: {str(e)}",
              "symbol": symbol,
              "date": date
          }

• polygon_api.py:147-164 (helper)

  Wrapper function imported by server.py that instantiates the API client, fetches data, formats it, and returns the string result.

  def get_stock_data(symbol: str, date: Optional[str] = None) -> str:
      """
      Convenience function to get formatted stock data.
      
      Args:
          symbol: Stock symbol (e.g., 'AAPL', 'MSFT', 'GOOGL')
          date: Date in YYYY-MM-DD format. If not provided, uses last working day.
      
      Returns:
          Formatted string with stock OHLC data
      """
      try:
          api = PolygonStockAPI()
          data = api.get_stock_ohlc(symbol, date)
          return api.format_stock_data(data)
      except Exception as e:
          return f"Error initializing API: {str(e)}"

• polygon_api.py:28-45 (helper)

  Helper method to determine the last working day (weekday) if no date is specified.

  def get_last_working_day(self) -> str:
      """
      Get the last working day (excluding weekends).
      
      Returns:
          Date string in YYYY-MM-DD format
      """
      today = datetime.now()
      
      # Go back to find the last working day
      days_back = 1
      while True:
          check_date = today - timedelta(days=days_back)
          # Monday = 0, Sunday = 6
          if check_date.weekday() < 5:  # Monday to Friday
              return check_date.strftime("%Y-%m-%d")
          days_back += 1

• polygon_api.py:121-144 (helper)

  Helper method to format the raw stock data dictionary into a human-readable string.

      def format_stock_data(self, data: Dict) -> str:
          """
          Format stock data into a readable string.
          
          Args:
              data: Stock data dictionary from get_stock_ohlc
              
          Returns:
              Formatted string with stock information
          """
          if "error" in data:
              return f"Error fetching data for {data.get('symbol', 'Unknown')}: {data['error']}"
          
          return f"""
  Stock Symbol: {data['symbol']}
  Date: {data['date']}
  Open: ${data['open']:.2f}
  High: ${data['high']:.2f}
  Low: ${data['low']:.2f}
  Close: ${data['close']:.2f}
  Volume: {data['volume']:,}
  VWAP: ${data['volume_weighted_average_price']:.2f}
  Transactions: {data['number_of_transactions']:,}
  """