MCP Yahoo Finance

Instructions

Implementation Reference

• src/mcp_yahoo_finance/server.py:120-136 (handler)

  Core handler function for the get_cashflow tool. Fetches cashflow statements using yfinance Ticker.get_cashflow() and formats as pretty JSON string.

  def get_cashflow(
      self, symbol: str, freq: Literal["yearly", "quarterly", "trainling"] = "yearly"
  ):
      """Get cashflow for a given stock symbol.
  
      Args:
          symbol (str): Stock symbol in Yahoo Finance format.
          freq (str): At what frequency to get cashflow statements. Defaults to "yearly".
                  Valid freqencies: "yearly", "quarterly", "trainling"
      """
      stock = Ticker(ticker=symbol, session=self.session)
      cashflow = stock.get_cashflow(freq=freq, pretty=True)
  
      if isinstance(cashflow, pd.DataFrame):
          cashflow.columns = [str(col.date()) for col in cashflow.columns]
          return f"{cashflow.to_json(indent=2)}"
      return f"{cashflow}"

• src/mcp_yahoo_finance/server.py:229-229 (registration)

  Registers the get_cashflow tool in the MCP server's tool list by generating a Tool object from the handler function.

  generate_tool(yf.get_cashflow),

• src/mcp_yahoo_finance/server.py:258-260 (handler)

  Dispatch handler in the MCP server's call_tool method that invokes the get_cashflow function with arguments and returns the result as TextContent.

  case "get_cashflow":
      price = yf.get_cashflow(**args)
      return [TextContent(type="text", text=price)]

• src/mcp_yahoo_finance/utils.py:31-65 (helper)

  Helper utility that inspects the handler function to generate the MCP Tool object, including input schema from signature and docstring.

  def generate_tool(func: Any) -> Tool:
      """Generates a tool schema from a Python function."""
      signature = inspect.signature(func)
      docstring = inspect.getdoc(func) or ""
      param_descriptions = parse_docstring(docstring)
  
      schema = {
          "name": func.__name__,
          "description": docstring.split("Args:")[0].strip(),
          "inputSchema": {
              "type": "object",
              "properties": {},
          },
      }
  
      for param_name, param in signature.parameters.items():
          param_type = (
              "number"
              if param.annotation is float
              else "string"
              if param.annotation is str
              else "string"
          )
          schema["inputSchema"]["properties"][param_name] = {
              "type": param_type,
              "description": param_descriptions.get(param_name, ""),
          }
  
          if "required" not in schema["inputSchema"]:
              schema["inputSchema"]["required"] = [param_name]
          else:
              if "=" not in str(param):
                  schema["inputSchema"]["required"].append(param_name)
  
      return Tool(**schema)

• src/mcp_yahoo_finance/server.py:120-122 (schema)

  Type annotations and signature that define the input schema for the tool (symbol: str, freq: Literal[...]).

  def get_cashflow(
      self, symbol: str, freq: Literal["yearly", "quarterly", "trainling"] = "yearly"
  ):