get_order_book

Instructions

Fetch order book data from Aster Finance API and return as Markdown table text.

Parameters:
    symbol (str): Trading pair symbol (e.g., 'BTCUSDT', 'ETHUSDT'). Case-insensitive.
    limit (Optional[int]): Number of order book entries to return (5, 10, 20, 50, 100, 500, 1000, 5000).
                          If None, defaults to 100.

Returns:
    str: Markdown table containing side (bid or ask), price, and quantity.

Raises:
    Exception: If the API request fails or data processing encounters an error.

Implementation Reference

• main.py:554-623 (handler)

  The handler function 'get_order_book' fetches order book data from the Aster Finance API (/fapi/v1/depth), processes bids and asks into a pandas DataFrame, formats it, and returns a Markdown table. The @mcp.tool() decorator registers the tool and infers the input schema from the function signature (symbol: str, optional limit: int).

  @mcp.tool()
  async def get_order_book(
      symbol: str,
      limit: Optional[int] = None
  ) -> str:
      """
      Fetch order book data from Aster Finance API and return as Markdown table text.
      
      Parameters:
          symbol (str): Trading pair symbol (e.g., 'BTCUSDT', 'ETHUSDT'). Case-insensitive.
          limit (Optional[int]): Number of order book entries to return (5, 10, 20, 50, 100, 500, 1000, 5000).
                                If None, defaults to 100.
      
      Returns:
          str: Markdown table containing side (bid or ask), price, and quantity.
      
      Raises:
          Exception: If the API request fails or data processing encounters an error.
      """
      endpoint = "/fapi/v1/depth"
      
      # Construct query parameters
      params = {
          "symbol": symbol.upper(),  # Ensure symbol is uppercase (e.g., BTCUSDT)
      }
      if limit is not None:
          params["limit"] = limit
  
      async with httpx.AsyncClient() as client:
          try:
              # Make GET request to the API
              response = await client.get(f"{BASE_URL}{endpoint}", params=params)
              response.raise_for_status()  # Raise exception for 4xx/5xx errors
              
              # Parse JSON response
              order_book_data = response.json()
              
              # Extract bids and asks
              bids = order_book_data.get("bids", [])
              asks = order_book_data.get("asks", [])
              
              # Create DataFrames for bids and asks
              bids_df = pd.DataFrame(bids, columns=["price", "quantity"])
              bids_df["side"] = "bid"
              asks_df = pd.DataFrame(asks, columns=["price", "quantity"])
              asks_df["side"] = "ask"
              
              # Combine bids and asks, sorting by price (descending for bids, ascending for asks)
              df = pd.concat([bids_df, asks_df], ignore_index=True)
              df["price"] = df["price"].astype(float)
              df = df.sort_values(by=["side", "price"], ascending=[True, False])
              
              # Format numbers
              df["price"] = df["price"].round(8)
              df["quantity"] = df["quantity"].astype(float).round(8)
              
              # Reorder columns
              df = df[["side", "price", "quantity"]]
              
              # Convert DataFrame to Markdown table
              markdown_table = df.to_markdown(index=False)
              
              return markdown_table
          
          except httpx.HTTPStatusError as e:
              # Handle HTTP errors (e.g., 400, 429)
              raise Exception(f"API request failed: {e.response.status_code} - {e.response.text}")
          except Exception as e:
              # Handle other errors (e.g., network issues, pandas errors)
              raise Exception(f"Error processing order book data: {str(e)}")            

• main.py:554-554 (registration)

  The @mcp.tool() decorator on get_order_book registers it as an MCP tool.

  @mcp.tool()

• main.py:555-558 (schema)

  Input schema inferred from type hints: required 'symbol' (str), optional 'limit' (int). Output: str (Markdown table).

  async def get_order_book(
      symbol: str,
      limit: Optional[int] = None
  ) -> str: