✅ Get Symbol Double Property

Request: get numeric (double) property of trading symbol, such as BID, ASK, POINT, volumes, spreads and other trading parameters.

API Information:

• Low-level API: MT5Account.SymbolInfoDouble(...) (from Go package github.com/MetaRPC/GoMT5/package/Helpers)
• gRPC service: mt5_term_api.MarketInfo
• Proto definition: SymbolInfoDouble (defined in mt5-term-api-market-info.proto)

RPC

• Service: mt5_term_api.MarketInfo
• Method: SymbolInfoDouble(SymbolInfoDoubleRequest) → SymbolInfoDoubleReply
• Low‑level client (generated): MarketInfoClient.SymbolInfoDouble(ctx, request, opts...)

💬 Just the essentials

• What it is. Retrieves numeric (double) properties of a trading symbol.
• Why you need it. Get current prices, point size, volume limits, and other trading parameters.
• Property ID required. Must specify which property to retrieve using PropertyId enum.

---

🎯 Purpose

Use it to:

• Get current Bid/Ask prices
• Retrieve point size for price calculations
• Check minimum/maximum trading volumes
• Obtain tick size and value for order placement
• Calculate trading parameters

---

📚 Tutorial

For a detailed line-by-line explanation with examples, see: → SymbolInfoDouble - How it works

---

package mt5

type MT5Account struct {
    // ...
}

// SymbolInfoDouble retrieves a double-type symbol property.
// Use PropertyId to specify which property (BID, ASK, POINT, VOLUME_MIN, etc).
func (a *MT5Account) SymbolInfoDouble(
    ctx context.Context,
    req *pb.SymbolInfoDoubleRequest,
) (*pb.SymbolInfoDoubleData, error)

Request message:

SymbolInfoDoubleRequest {
  string Symbol = 1;       // Symbol name
  int32 PropertyId = 2;    // Property identifier (BID, ASK, POINT, etc)
}

Reply message:

SymbolInfoDoubleReply {
  oneof response {
    SymbolInfoDoubleData data = 1;
    Error error = 2;
  }
}

---

🔽 Input

Parameter	Type	Description
ctx	context.Context	Context for deadline/timeout and cancellation
req	*pb.SymbolInfoDoubleRequest	Request with Symbol and PropertyId

Request fields:

Field	Type	Description
Symbol	string	Symbol name (e.g., "EURUSD")
PropertyId	int32	Property identifier from SymbolInfoDoubleProperty enum

PropertyId enum values (SymbolInfoDoubleProperty):

Constant	Value	Description
SYMBOL_BID	0	Current Bid price
SYMBOL_BIDHIGH	1	Highest Bid of the day
SYMBOL_BIDLOW	2	Lowest Bid of the day
SYMBOL_ASK	3	Current Ask price
SYMBOL_ASKHIGH	4	Highest Ask of the day
SYMBOL_ASKLOW	5	Lowest Ask of the day
SYMBOL_LAST	6	Last deal price
SYMBOL_LASTHIGH	7	Highest Last price of the day
SYMBOL_LASTLOW	8	Lowest Last price of the day
SYMBOL_VOLUME_REAL	9	Last deal volume
SYMBOL_VOLUMEHIGH_REAL	10	Maximum volume of the day
SYMBOL_VOLUMELOW_REAL	11	Minimum volume of the day
SYMBOL_OPTION_STRIKE	12	Option strike price
SYMBOL_POINT	13	Point size (smallest price change)
SYMBOL_TRADE_TICK_VALUE	14	Tick value in account currency
SYMBOL_TRADE_TICK_VALUE_PROFIT	15	Tick value for profit position
SYMBOL_TRADE_TICK_VALUE_LOSS	16	Tick value for loss position
SYMBOL_TRADE_TICK_SIZE	17	Minimum price change
SYMBOL_TRADE_CONTRACT_SIZE	18	Contract size (lot size in base currency)
SYMBOL_TRADE_ACCRUED_INTEREST	19	Accrued interest
SYMBOL_TRADE_FACE_VALUE	20	Face value (for bonds)
SYMBOL_TRADE_LIQUIDITY_RATE	21	Liquidity rate
SYMBOL_VOLUME_MIN	22	Minimum volume for trading
SYMBOL_VOLUME_MAX	23	Maximum volume for trading
SYMBOL_VOLUME_STEP	24	Volume step (lot size increment)
SYMBOL_VOLUME_LIMIT	25	Maximum total volume of open positions
SYMBOL_SWAP_LONG	26	Swap for long positions
SYMBOL_SWAP_SHORT	27	Swap for short positions
SYMBOL_SWAP_SUNDAY	28	Triple swap day - Sunday
SYMBOL_SWAP_MONDAY	29	Triple swap day - Monday
SYMBOL_SWAP_TUESDAY	30	Triple swap day - Tuesday
SYMBOL_SWAP_WEDNESDAY	31	Triple swap day - Wednesday
SYMBOL_SWAP_THURSDAY	32	Triple swap day - Thursday
SYMBOL_SWAP_FRIDAY	33	Triple swap day - Friday
SYMBOL_SWAP_SATURDAY	34	Triple swap day - Saturday
SYMBOL_MARGIN_INITIAL	35	Initial margin
SYMBOL_MARGIN_MAINTENANCE	36	Maintenance margin
SYMBOL_SESSION_VOLUME	37	Summary volume of the current session
SYMBOL_SESSION_TURNOVER	38	Summary turnover of the current session
SYMBOL_SESSION_INTEREST	39	Summary open interest
SYMBOL_SESSION_BUY_ORDERS_VOLUME	40	Current volume of Buy orders
SYMBOL_SESSION_SELL_ORDERS_VOLUME	41	Current volume of Sell orders
SYMBOL_SESSION_OPEN	42	Open price of the current session
SYMBOL_SESSION_CLOSE	43	Close price of the current session
SYMBOL_SESSION_AW	44	Average weighted price of the current session
SYMBOL_SESSION_PRICE_SETTLEMENT	45	Settlement price of the current session
SYMBOL_SESSION_PRICE_LIMIT_MIN	46	Minimum price of the current session
SYMBOL_SESSION_PRICE_LIMIT_MAX	47	Maximum price of the current session
SYMBOL_MARGIN_HEDGED	48	Hedged margin
SYMBOL_PRICE_CHANGE	49	Change of price in %
SYMBOL_PRICE_VOLATILITY	50	Price volatility in %
SYMBOL_PRICE_THEORETICAL	51	Theoretical option price
SYMBOL_PRICE_DELTA	52	Option/warrant delta
SYMBOL_PRICE_THETA	53	Option/warrant theta
SYMBOL_PRICE_GAMMA	54	Option/warrant gamma
SYMBOL_PRICE_VEGA	55	Option/warrant vega
SYMBOL_PRICE_RHO	56	Option/warrant rho
SYMBOL_PRICE_OMEGA	57	Option/warrant omega
SYMBOL_PRICE_SENSITIVITY	58	Option/warrant sensitivity
SYMBOL_COUNT	59	Total number of properties (not used)

---

⬆️ Output — SymbolInfoDoubleData

Field	Type	Go Type	Description
Value	double	float64	The requested double property value

---

🧩 Notes & Tips

• Automatic reconnection: All MT5Account methods have built-in protection against transient gRPC errors with automatic reconnection via ExecuteWithReconnect.
• Default timeout: If context has no deadline, a default 3s timeout is applied automatically.
• Nil context: If you pass nil context, context.Background() is used automatically.
• Synchronization: Symbol should be synchronized for accurate real-time prices.
• Performance: For multiple properties, consider using SymbolParamsMany instead.

---

🔗 Usage Examples

1) Get current Bid price

package main

import (
    "context"
    "fmt"
    "time"

    pb "github.com/MetaRPC/GoMT5/package"
    "github.com/MetaRPC/GoMT5/package/Helpers"
)

func main() {
    account, _ := mt5.NewMT5Account(12345, "password", "mt5.mrpc.pro:443", uuid.New())
    defer account.Close()

    ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
    defer cancel()

    data, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     "EURUSD",
        PropertyId: 0, // SYMBOL_BID
    })
    if err != nil {
        panic(err)
    }

    fmt.Printf("EURUSD Bid: %.5f\n", data.Value)
}

2) Get Bid and Ask spread

func GetSpread(account *mt5.MT5Account, symbol string) (float64, error) {
    ctx := context.Background()

    // Get Bid
    bidData, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     symbol,
        PropertyId: 0, // SYMBOL_BID
    })
    if err != nil {
        return 0, err
    }

    // Get Ask
    askData, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     symbol,
        PropertyId: 3, // SYMBOL_ASK
    })
    if err != nil {
        return 0, err
    }

    spread := askData.Value - bidData.Value
    return spread, nil
}

3) Get point size for calculations

func GetPointSize(account *mt5.MT5Account, symbol string) (float64, error) {
    ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
    defer cancel()

    data, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     symbol,
        PropertyId: 13, // SYMBOL_POINT
    })
    if err != nil {
        return 0, fmt.Errorf("failed to get point: %w", err)
    }

    return data.Value, nil
}

// Usage for stop-loss calculation:
// point, _ := GetPointSize(account, "EURUSD")
// slDistance := 50 * point  // 50 pips

4) Check minimum trading volume

func GetVolumeConstraints(account *mt5.MT5Account, symbol string) (min, max, step float64, err error) {
    ctx := context.Background()

    // Get minimum volume
    minData, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     symbol,
        PropertyId: 22, // SYMBOL_VOLUME_MIN
    })
    if err != nil {
        return 0, 0, 0, err
    }

    // Get maximum volume
    maxData, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     symbol,
        PropertyId: 23, // SYMBOL_VOLUME_MAX
    })
    if err != nil {
        return 0, 0, 0, err
    }

    // Get volume step
    stepData, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     symbol,
        PropertyId: 24, // SYMBOL_VOLUME_STEP
    })
    if err != nil {
        return 0, 0, 0, err
    }

    return minData.Value, maxData.Value, stepData.Value, nil
}

5) Calculate pip value

func CalculatePipValue(account *mt5.MT5Account, symbol string) (float64, error) {
    ctx := context.Background()

    // Get tick size
    tickSizeData, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     symbol,
        PropertyId: 17, // SYMBOL_TRADE_TICK_SIZE
    })
    if err != nil {
        return 0, err
    }

    // Get tick value
    tickValueData, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     symbol,
        PropertyId: 14, // SYMBOL_TRADE_TICK_VALUE
    })
    if err != nil {
        return 0, err
    }

    // Get point
    pointData, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     symbol,
        PropertyId: 13, // SYMBOL_POINT
    })
    if err != nil {
        return 0, err
    }

    // Pip value = (tick value / tick size) * point
    pipValue := (tickValueData.Value / tickSizeData.Value) * pointData.Value
    return pipValue, nil
}

6) Monitor price changes

func MonitorPrice(account *mt5.MT5Account, symbol string, interval time.Duration) {
    ctx := context.Background()
    ticker := time.NewTicker(interval)
    defer ticker.Stop()

    var lastBid float64

    for range ticker.C {
        data, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
            Symbol:     symbol,
            PropertyId: 0, // SYMBOL_BID
        })

        if err != nil {
            fmt.Printf("Error: %v\n", err)
            continue
        }

        if lastBid != 0 {
            change := data.Value - lastBid
            fmt.Printf("[%s] %s: %.5f (change: %+.5f)\n",
                time.Now().Format("15:04:05"),
                symbol,
                data.Value,
                change,
            )
        }

        lastBid = data.Value
    }
}

---

🔧 Common Patterns

Get current price with validation

func GetCurrentPrice(account *mt5.MT5Account, symbol string, isBid bool) (float64, error) {
    ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
    defer cancel()

    propertyId := int32(1) // BID
    if !isBid {
        propertyId = 2 // ASK
    }

    data, err := account.SymbolInfoDouble(ctx, &pb.SymbolInfoDoubleRequest{
        Symbol:     symbol,
        PropertyId: propertyId,
    })

    if err != nil {
        return 0, fmt.Errorf("failed to get price: %w", err)
    }

    if data.Value <= 0 {
        return 0, fmt.Errorf("invalid price: %.5f", data.Value)
    }

    return data.Value, nil
}

Validate lot size

func ValidateLotSize(account *mt5.MT5Account, symbol string, volume float64) (float64, error) {
    ctx := context.Background()

    min, max, step, err := GetVolumeConstraints(account, symbol)
    if err != nil {
        return 0, err
    }

    if volume < min {
        return min, nil
    }
    if volume > max {
        return max, nil
    }

    // Round to step
    adjusted := math.Round(volume/step) * step
    return adjusted, nil
}

---

📚 See Also

• SymbolInfoInteger - Get integer symbol properties
• SymbolInfoString - Get string symbol properties
• SymbolParamsMany - Get all symbol parameters at once
• SymbolInfoTick - Get tick data with prices