✅ Modifying Orders and Positions (OrderModifyAsync)

Request: Modify SL/TP of an open position or modify parameters of a pending order on MT5.

API Information:

• SDK wrapper: MT5Account.OrderModifyAsync(...) (from NuGet package MetaRPC.MT5)
• gRPC service: mt5_term_api.TradingHelper
• Proto definition: OrderModify (defined in mt5-term-api-trading-helper.proto)

RPC

• Service: mt5_term_api.TradingHelper
• Method: OrderModify(OrderModifyRequest) → OrderModifyReply
• Low‑level client (generated): TradingHelper.TradingHelperClient.OrderModify(request, headers, deadline, cancellationToken)
• SDK wrapper (your class):

namespace mt5_term_api
{
    public class MT5Account
    {
        public async Task<OrderModifyData> OrderModifyAsync(
            OrderModifyRequest request,
            DateTime? deadline = null,
            CancellationToken cancellationToken = default);
    }
}

Request message:

OrderModifyRequest { ticket, stop_loss, take_profit, ... }

Reply message:

OrderModifyReply { data: OrderModifyData }

---

🔽 Input

Parameter	Type	Description
request	OrderModifyRequest	Protobuf request with modification parameters
deadline	DateTime?	Absolute per‑call UTC deadline → converted to timeout
cancellationToken	CancellationToken	Cooperative cancel for the call/retry loop

OrderModifyRequest

Field	Type	Description
Ticket	ulong	Position or pending order ticket REQUIRED
StopLoss	double	New Stop Loss level (for positions and pending orders)
TakeProfit	double	New Take Profit level (for positions and pending orders)
Price	double	New price (ONLY for pending orders)
ExpirationTimeType	TMT5_ENUM_ORDER_TYPE_TIME	Expiration type (ONLY for pending orders)
ExpirationTime	Timestamp	Expiration time (ONLY for pending orders)
StopLimit	double	New stop limit (ONLY for pending StopLimit orders)

---

⬆️ Output — OrderModifyData

Field	Type	Description
ReturnedCode	uint	Operation return code (10009 = success)
Deal	ulong	Deal ticket if executed
Order	ulong	Order ticket
Volume	double	Confirmed volume
Price	double	Confirmed price
Bid	double	Current Bid price
Ask	double	Current Ask price
Comment	string	Broker comment (error description)
RequestId	uint	Request ID from terminal
RetCodeExternal	int	External trading system return code
ReturnedStringCode	string	String representation of return code
ReturnedCodeDescription	string	Human-readable description

---

🧱 Related enums (from proto)

TMT5_ENUM_ORDER_TYPE_TIME

• Tmt5OrderTimeGtc — Good‑Till‑Cancelled
• Tmt5OrderTimeDay — Good till current trade day
• Tmt5OrderTimeSpecified — Good till expiration time
• Tmt5OrderTimeSpecifiedDay — Good till 23:59:59 of specified day

---

💬 Just the essentials

• What it is. Modifies SL/TP of open positions or changes parameters of pending orders (price, expiration, stop limit).
• Why you need it. Adjust risk levels, move to breakeven, update pending order prices.
• Sanity check. If ReturnedCode == 10009 → modification successful.

---

🎯 Purpose

Use it to update trade parameters:

• Modify SL/TP of open positions.
• Change pending order price/expiration.
• Move stops to breakeven.
• Adjust trailing stops manually.

---

🧩 Notes & Tips

• Return codes: 10009 = success. Other codes indicate errors (invalid stops, market closed, etc.).
• Position vs Pending: Use same Ticket for both positions and pending orders. Server determines type automatically.
• Stop levels: Broker enforces minimum distance from current price (SYMBOL_TRADE_STOPS_LEVEL). Check before modifying.
• Partial parameters: Set only fields you want to change. Leave others as 0 or null.
• Price field: Only for pending orders. Ignored for open positions.

---

🔗 Usage Examples

1) Modify SL/TP of open position

// acc — connected MT5Account
// positionTicket — ticket from OrderSendAsync or OpenedOrdersAsync

var result = await acc.OrderModifyAsync(new OrderModifyRequest
{
    Ticket = positionTicket,
    StopLoss = 1.1050,
    TakeProfit = 1.1150
});

if (result.ReturnedCode == 10009)
{
    Console.WriteLine($"✓ Position modified: SL={result.Price}");
}
else
{
    Console.WriteLine($"✗ Modification failed: {result.ReturnedCodeDescription}");
}

---

2) Move position to breakeven

// Get current position
var positions = await acc.OpenedOrdersAsync();
var position = positions.Positions.First();

// Get entry price from position
var entryPrice = position.PriceOpen;

var result = await acc.OrderModifyAsync(new OrderModifyRequest
{
    Ticket = (ulong)position.Ticket,
    StopLoss = entryPrice,  // Move SL to entry price
    TakeProfit = position.TakeProfit  // Keep existing TP
});

Console.WriteLine($"Moved to breakeven: {result.ReturnedCodeDescription}");

---

3) Remove SL/TP (set to zero)

var result = await acc.OrderModifyAsync(new OrderModifyRequest
{
    Ticket = positionTicket,
    StopLoss = 0,    // Remove SL
    TakeProfit = 0   // Remove TP
});

Console.WriteLine($"Removed SL/TP: {result.ReturnedCodeDescription}");

---

4) Modify pending order price

// pendingOrderTicket — ticket of pending Buy Limit order

var tick = await acc.SymbolInfoTickAsync("EURUSD");
var newPrice = tick.Bid - 0.0020; // 20 pips below current

var result = await acc.OrderModifyAsync(new OrderModifyRequest
{
    Ticket = pendingOrderTicket,
    Price = newPrice,
    StopLoss = newPrice - 0.0010,
    TakeProfit = newPrice + 0.0030
});

Console.WriteLine($"Pending order updated: {result.ReturnedCodeDescription}");

---

5) Change pending order expiration

var result = await acc.OrderModifyAsync(new OrderModifyRequest
{
    Ticket = pendingOrderTicket,
    ExpirationTimeType = TMT5_ENUM_ORDER_TYPE_TIME.Tmt5OrderTimeSpecified,
    ExpirationTime = Google.Protobuf.WellKnownTypes.Timestamp.FromDateTime(
        DateTime.UtcNow.AddDays(1))
});

Console.WriteLine($"Order expires in 1 day: {result.ReturnedCodeDescription}");

---

6) Trailing stop example (manual)

// Simple trailing stop: if position in profit >= 30 pips, move SL to +10 pips
var positions = await acc.OpenedOrdersAsync();
var position = positions.Positions.FirstOrDefault(p => p.Symbol == "EURUSD");

if (position != null)
{
    var currentProfit = position.Profit;
    var currentPrice = position.Type == 0 ? position.PriceCurrent : position.PriceCurrent; // Bid for Buy, Ask for Sell
    var entryPrice = position.PriceOpen;

    var profitPips = Math.Abs(currentPrice - entryPrice) * 10000;

    if (profitPips >= 30)
    {
        var newSL = position.Type == 0
            ? entryPrice + 0.0010  // Buy: SL 10 pips above entry
            : entryPrice - 0.0010; // Sell: SL 10 pips below entry

        var result = await acc.OrderModifyAsync(new OrderModifyRequest
        {
            Ticket = (ulong)position.Ticket,
            StopLoss = newSL,
            TakeProfit = position.TakeProfit
        });

        Console.WriteLine($"Trailing stop updated: {result.ReturnedCodeDescription}");
    }
}