Banxico MCP Server

Instructions

Implementation Reference

• banxico_mcp_server.py:342-369 (handler)

  The handler function decorated with @mcp.tool(), which registers and implements the tool. Fetches historical USD/MXN exchange rates (series SF63528) from Banxico API, optionally limits to recent N points, and formats the output using helper functions.
  @mcp.tool() async def get_usd_mxn_historical_data(limit: Optional[int] = 30) -> str: """ Get historical USD/MXN exchange rate data from Banxico. Args: limit: Maximum number of recent data points to return (default: 30) Returns: Historical USD/MXN exchange rate data """ if not BANXICO_TOKEN: return "Error: BANXICO_API_TOKEN environment variable not set. Please configure your API token." endpoint = "series/SF63528/datos" data = await make_banxico_request(endpoint, BANXICO_TOKEN) if not data: return "Failed to retrieve historical exchange rate data. Please check your API token and network connection." # If limit is specified, truncate the data if limit and data.get("bmx", {}).get("series"): for series in data["bmx"]["series"]: if "datos" in series and len(series["datos"]) > limit: # Keep the most recent data points series["datos"] = series["datos"][-limit:] return format_exchange_rate_data(data)
• banxico_mcp_server.py:71-122 (helper)

  Helper function to format the raw Banxico API response for exchange rate data into a human-readable string, handling multiple series and truncating long lists.
  def format_exchange_rate_data(data: dict[str, Any]) -> str: """ Format exchange rate data into a readable string. Args: data: Raw JSON response from Banxico API Returns: Formatted string with exchange rate information """ if not data or "bmx" not in data: return "No data available" series_list = data["bmx"].get("series", []) if not series_list: return "No series data found" result = [] for series in series_list: series_title = series.get("titulo", "Unknown Series") series_id = series.get("idSerie", "Unknown ID") result.append(f"Series: {series_title} (ID: {series_id})") datos = series.get("datos", []) if not datos: result.append(" No data points available") else: result.append(f" Total data points: {len(datos)}") # Show first few and last few data points if len(datos) <= 10: for dato in datos: fecha = dato.get("fecha", "Unknown date") valor = dato.get("dato", "N/A") result.append(f" {fecha}: {valor}") else: # Show first 5 for i, dato in enumerate(datos[:5]): fecha = dato.get("fecha", "Unknown date") valor = dato.get("dato", "N/A") result.append(f" {fecha}: {valor}") result.append(f" ... ({len(datos) - 10} more data points) ...") # Show last 5 for dato in datos[-5:]: fecha = dato.get("fecha", "Unknown date") valor = dato.get("dato", "N/A") result.append(f" {fecha}: {valor}") result.append("") # Empty line between series return "\n".join(result)
• banxico_mcp_server.py:43-69 (helper)

  Helper function that makes authenticated async HTTP requests to the Banxico SIE API, handles errors, and returns parsed JSON or None.
  async def make_banxico_request(endpoint: str, token: str) -> dict[str, Any] | None: """ Make a request to the Banxico SIE API with proper error handling. Args: endpoint: The API endpoint to call (without base URL) token: The Banxico API token Returns: JSON response data or None if request failed """ url = f"{BANXICO_API_BASE}/{endpoint}" headers = {"User-Agent": USER_AGENT} params = {"token": token} try: async with httpx.AsyncClient() as client: response = await client.get(url, headers=headers, params=params, timeout=30.0) response.raise_for_status() return response.json() except httpx.HTTPError as e: logger.error(f"HTTP error occurred: {e}") return None except Exception as e: logger.error(f"An error occurred: {e}") return None