get_exchanges
Retrieve a list of exchanges supported by Polygon.io. Filter results by asset class or locale to access specific market data efficiently.
Instructions
List exchanges known by Polygon.io.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| asset_class | No | ||
| locale | No | ||
| params | No |
Implementation Reference
- src/mcp_massive/server.py:687-704 (handler)The primary handler function for the 'get_exchanges' MCP tool. It is registered via the @poly_mcp.tool decorator, validates inputs via type hints, calls the underlying massive_client.get_exchanges method with optional asset_class, locale, and params, processes the raw binary response by decoding and converting to CSV using json_to_csv helper, and returns the formatted string or an error message.@poly_mcp.tool(annotations=ToolAnnotations(readOnlyHint=True)) async def get_exchanges( asset_class: Optional[str] = None, locale: Optional[str] = None, params: Optional[Dict[str, Any]] = None, ) -> str: """ List exchanges known by Massive.com. """ try: results = massive_client.get_exchanges( asset_class=asset_class, locale=locale, params=params, raw=True ) return json_to_csv(results.data.decode("utf-8")) except Exception as e: return f"Error: {e}"
- src/mcp_massive/formatters.py:7-74 (helper)Supporting utility function json_to_csv that flattens nested JSON responses from the Massive API (handling 'results' or 'last' keys, lists, dicts) into a CSV string with headers, used by get_exchanges and all other tools to format output.def json_to_csv(json_input: str | dict) -> str: """ Convert JSON to flattened CSV format. Args: json_input: JSON string or dict. If the JSON has a 'results' key containing a list, it will be extracted. Otherwise, the entire structure will be wrapped in a list for processing. Returns: CSV string with headers and flattened rows """ # Parse JSON if it's a string if isinstance(json_input, str): try: data = json.loads(json_input) except json.JSONDecodeError: # If JSON parsing fails, return empty CSV return "" else: data = json_input if isinstance(data, dict) and "results" in data: results_value = data["results"] # Handle both list and single object responses if isinstance(results_value, list): records = results_value elif isinstance(results_value, dict): # Single object response (e.g., get_last_trade returns results as object) records = [results_value] else: records = [results_value] elif isinstance(data, dict) and "last" in data: # Handle responses with "last" key (e.g., get_last_trade, get_last_quote) records = [data["last"]] if isinstance(data["last"], dict) else [data] elif isinstance(data, list): records = data else: records = [data] # Only flatten dict records, skip non-dict items flattened_records = [] for record in records: if isinstance(record, dict): flattened_records.append(_flatten_dict(record)) else: # If it's not a dict, wrap it in a dict with a 'value' key flattened_records.append({"value": str(record)}) if not flattened_records: return "" # Get all unique keys across all records (for consistent column ordering) all_keys = [] seen = set() for record in flattened_records: if isinstance(record, dict): for key in record.keys(): if key not in seen: all_keys.append(key) seen.add(key) output = io.StringIO() writer = csv.DictWriter(output, fieldnames=all_keys, lineterminator="\n") writer.writeheader() writer.writerows(flattened_records) return output.getvalue()
- src/mcp_massive/server.py:687-687 (registration)The @poly_mcp.tool decorator registers the get_exchanges function as an MCP tool with readOnlyHint=True annotation.@poly_mcp.tool(annotations=ToolAnnotations(readOnlyHint=True))