Adding Alerts & Push Notifications

Why Alerts Matter

An indicator that requires you to watch the chart constantly defeats its purpose. Alerts let your indicator notify you when conditions are met — so you can step away from the screen and still catch every signal.

MQL5 provides four alert delivery methods, from simple on-screen pop-ups to mobile push notifications.

Alert Types in MQL5

1. Pop-up Alert — A dialog box with a sound. The simplest and most common.

Alert("EURUSD: RSI crossed above 70 - Overbought!");

You can pass multiple arguments and they will be concatenated:

Alert(_Symbol, " | ", EnumToString(_Period), " | RSI: ",
      DoubleToString(rsiValue, 1), " - OVERBOUGHT");

2. Sound Alert — Play a .wav file without a dialog box. Less intrusive.

PlaySound("alert.wav");  // plays from MQL5/Sounds/ folder

3. Push Notification — Sends to your phone via the MetaTrader mobile app. You must configure your MetaQuotes ID in MT5 (Tools > Options > Notifications).

SendNotification("EURUSD Buy Signal - RSI: " + DoubleToString(rsiValue, 1));

4. Email Alert — Sends an email. Requires SMTP configuration in MT5 (Tools > Options > Email).

SendMail("Trading Alert: EURUSD",
         "Buy signal detected.
RSI: " + DoubleToString(rsiValue, 1) +
         "
Time: " + TimeToString(TimeCurrent()));

Preventing Duplicate Alerts

The biggest mistake in alert coding: firing the same alert hundreds of times because the condition remains true across multiple ticks. You must ensure each alert fires once per signal.

// Method 1: Track the last alert bar
datetime lastAlertBar = 0;

void CheckAlert(double rsiValue, datetime barTime)
{
    if(barTime == lastAlertBar) return;  // already alerted this bar

    if(rsiValue > 70)
    {
        Alert(_Symbol, " RSI Overbought: ", DoubleToString(rsiValue, 1));
        lastAlertBar = barTime;
    }
    else if(rsiValue < 30)
    {
        Alert(_Symbol, " RSI Oversold: ", DoubleToString(rsiValue, 1));
        lastAlertBar = barTime;
    }
}

// Method 2: Track the signal state (better for crossover signals)
bool wasAbove70 = false;

void CheckCrossAlert(double rsiValue)
{
    bool isAbove70 = (rsiValue > 70);

    // Alert only on the TRANSITION from below to above
    if(isAbove70 && !wasAbove70)
    {
        Alert(_Symbol, " RSI crossed above 70");
    }
    // Alert on transition from above to below
    if(!isAbove70 && wasAbove70)
    {
        Alert(_Symbol, " RSI crossed below 70");
    }

    wasAbove70 = isAbove70;
}

Making Alerts Configurable

Professional indicators let users choose which alert types they want:

input bool EnablePopupAlert = true;   // Show Pop-up Alerts
input bool EnableSoundAlert = true;   // Play Sound
input bool EnablePushAlert  = false;  // Send Push Notification
input bool EnableEmailAlert = false;  // Send Email
input string AlertSound = "alert.wav"; // Alert Sound File

void FireAlert(string message)
{
    if(EnablePopupAlert)
        Alert(message);
    if(EnableSoundAlert)
        PlaySound(AlertSound);
    if(EnablePushAlert)
        SendNotification(message);
    if(EnableEmailAlert)
        SendMail("MT5 Alert: " + _Symbol, message);
}

Alert with Price Level

A practical pattern — alert when price crosses a moving average:

input bool AlertOnCross = true;  // Alert on MA Cross

datetime lastCrossAlert = 0;
bool wasPriceAboveMA = false;

void CheckMACrossAlert(double price, double maValue, datetime barTime)
{
    if(!AlertOnCross) return;
    if(barTime == lastCrossAlert) return;

    bool isPriceAboveMA = (price > maValue);

    if(isPriceAboveMA && !wasPriceAboveMA)
    {
        FireAlert(_Symbol + " Price crossed ABOVE MA " +
                  DoubleToString(maValue, _Digits));
        lastCrossAlert = barTime;
    }
    else if(!isPriceAboveMA && wasPriceAboveMA)
    {
        FireAlert(_Symbol + " Price crossed BELOW MA " +
                  DoubleToString(maValue, _Digits));
        lastCrossAlert = barTime;
    }

    wasPriceAboveMA = isPriceAboveMA;
}

Best Practices

• Always prevent duplicates — One alert per signal, not per tick
• Include context — Symbol, timeframe, indicator value, and timestamp in every alert message
• Make alerts optional — Use input parameters so users can enable/disable each alert type
• Use meaningful sounds — Different sounds for buy vs sell signals help when you are away from the screen
• Test on live charts — Alert behavior can differ between backtesting and live trading