Alpaca Trading MCP Server

Instructions

Implementation Reference

• src/server.py:270-313 (handler)

  Core handler for the 'place_market_order' tool. Validates input parameters, constructs an AlpacaOrderRequest for a MARKET order, submits it using the helper function calls.place_order, and formats the response with order details.
  @mcp.tool() def place_market_order(symbol: str, quantity: float, side: str) -> str: """ Place a market order to buy or sell a stock. Args: symbol: Stock symbol (e.g., 'AAPL') quantity: Number of shares to buy or sell (can be fractional) side: Either 'buy' or 'sell' Returns: Order confirmation details """ # Validate side try: order_side = AlpacaOrderSide(side.lower()) except ValueError: return f"Invalid side: {side}. Must be 'buy' or 'sell'." # Create order request order_request = AlpacaOrderRequest( symbol=symbol, qty=float(quantity), side=order_side, type=AlpacaOrderType.MARKET, time_in_force=AlpacaTimeInForce.DAY ) try: order = calls.place_order(trading_client, order_request) return ( f"Market order placed successfully!\n\n" f"Order ID: {order.id}\n" f"Symbol: {order.symbol}\n" f"Side: {order.side.value}\n" f"Type: {order.type.value}\n" f"Quantity: {order.qty}\n" f"Status: {order.status.value}\n" f"Created At: {order.created_at}\n" ) except Exception as e: return f"Error placing market order: {str(e)}"
• src/calls.py:44-97 (helper)

  Helper function that handles order submission to Alpaca API. Converts custom AlpacaOrderRequest model to Alpaca-native request objects based on order type and submits the order.
  def place_order(client: TradingClient, order_details: AlpacaOrderRequest): """ Place an order with flexible order types :param client: Alpaca trading client :param order_details: Order request details :return: Placed AlpacaOrder """ # Map Pydantic model to Alpaca order request based on order type if order_details.type == AlpacaOrderType.MARKET: order_request = MarketOrderRequest( symbol=order_details.symbol, qty=order_details.qty, side=order_details.side, time_in_force=order_details.time_in_force ) elif order_details.type == AlpacaOrderType.LIMIT: if not order_details.limit_price: raise ValueError("Limit price is required for limit orders") order_request = LimitOrderRequest( symbol=order_details.symbol, qty=order_details.qty, side=order_details.side, time_in_force=order_details.time_in_force, limit_price=order_details.limit_price ) elif order_details.type == AlpacaOrderType.STOP: if not order_details.stop_price: raise ValueError("Stop price is required for stop orders") order_request = StopOrderRequest( symbol=order_details.symbol, qty=order_details.qty, side=order_details.side, time_in_force=order_details.time_in_force, stop_price=order_details.stop_price ) elif order_details.type == AlpacaOrderType.STOP_LIMIT: if not (order_details.stop_price and order_details.limit_price): raise ValueError("Both stop and limit prices are required for stop-limit orders") order_request = StopLimitOrderRequest( symbol=order_details.symbol, qty=order_details.qty, side=order_details.side, time_in_force=order_details.time_in_force, stop_price=order_details.stop_price, limit_price=order_details.limit_price ) else: raise ValueError(f"Unsupported order type: {order_details.type}") # Submit order order = client.submit_order(order_request) return AlpacaOrder(**order.__dict__)
• src/models.py:87-97 (schema)

  Pydantic model defining the structure for order requests, used internally by the tool handler to create market orders. Includes type definitions for side, type, etc.
  class AlpacaOrderRequest(BaseModel): symbol: str qty: Union[int, float] side: AlpacaOrderSide type: AlpacaOrderType time_in_force: AlpacaTimeInForce limit_price: Optional[float] = None stop_price: Optional[float] = None client_order_id: Optional[str] = None extended_hours: Optional[bool] = False
• src/models.py:21-24 (schema)

  Enum defining valid order sides ('buy', 'sell'), used for input validation in the tool.
  class AlpacaOrderSide(str, Enum): BUY = 'buy' SELL = 'sell'