TradingView Pine Script Strategy Alerts Guide: Fire Webhooks to MT5

Getting a Pine Script strategy to actually place trades on MT5 comes down to one thing: firing the right alert with the right message at the right moment. This guide breaks down the two alert mechanisms in Pine — alert() and strategy alert_message — and shows the exact setup that reliably executes through a webhook copier.

alert() vs Strategy alert_message

Pine Script gives you two ways to fire an alert from a strategy. Choosing the right one is the difference between trades that copy cleanly and alerts that silently never fire.

Method 1 — alert_message on Strategy Orders

Attach a JSON payload to every order. When the order executes, TradingView posts that exact message to your webhook. The format follows our TradingView alert JSON guide.

//@version=5
strategy("Breakout Strategy", overlay=true, calc_on_every_tick=false)

longCond  = ta.crossover(close, ta.highest(high, 20)[1])
exitCond  = ta.crossunder(close, ta.lowest(low, 10)[1])

if longCond
    strategy.entry("Long", strategy.long,
         alert_message='{"action":"buy","symbol":"EURUSD","lot":0.10,"sl":50,"tp":100}')

if exitCond
    strategy.close("Long",
         alert_message='{"action":"close","symbol":"EURUSD"}')

Then in TradingView: open Create Alert, set Condition → your strategy, choose "Order fills only", tick Webhook URL, and paste your copier's URL. Leave the message box as the default {{strategy.order.alert_message}} so TradingView substitutes the JSON you defined.

Method 2 — Manual alert() Calls

When you need full control — for example to scale out with partial closes at custom levels — call alert() directly:

//@version=5
strategy("Custom Exits", overlay=true)

if longCond
    strategy.entry("Long", strategy.long)
    alert('{"action":"buy","symbol":"XAUUSD","lot":0.05,"sl":300,"tp":900}',
         alert.freq_once_per_bar_close)

if high >= strategy.position_avg_price * 1.01 and strategy.position_size > 0
    alert('{"action":"close","symbol":"XAUUSD","percent":50}',
         alert.freq_once_per_bar_close)

For alert() calls, create the TradingView alert with the "alert() function calls only" condition. The message box is ignored — Pine supplies the text.

Using Placeholders for Dynamic Values

Hard-coding the symbol and lot works, but you can make a strategy reusable with placeholders that TradingView fills in at fire time:

Wrap every placeholder in double quotes so the JSON stays valid:

{
  "action": "{{strategy.order.action}}",
  "symbol": "{{ticker}}",
  "lot": {{strategy.order.contracts}}
}

Avoiding Repaint and Duplicate Fires

1. Use bar-close evaluation — set the alert to Once Per Bar Close and use alert.freq_once_per_bar_close so signals don't repaint intrabar.
2. Avoid calc_on_every_tick=true unless you specifically want intrabar entries — it can fire and reverse within a bar.
3. Reference confirmed data — use [1] on series in conditions (e.g. ta.highest(high, 20)[1]) so you act on closed bars.
4. One alert per strategy — a single "Order fills only" alert covers every entry and exit; don't stack multiple alerts on the same strategy.

Why Strategy Alerts Don't Fire (Checklist)

• Alert created with the wrong condition (use "Order fills only" for alert_message, "alert() function calls only" for alert()).
• alert_message contains invalid JSON — validate it before going live.
• Alert timeframe differs from the chart the strategy runs on.
• Webhook URL box not ticked, or the copier's URL is wrong.
• Free TradingView plan — webhooks require a paid plan. See our note on which TradingView plans support webhooks.

Still stuck after these? Walk through the full webhook troubleshooting guide.

Frequently Asked Questions

What is the difference between alert() and strategy alerts in Pine Script?

alert() is a function you call manually inside your code at any condition, giving you full control over the message and when it fires. Strategy alerts use the alert_message argument on strategy.entry/strategy.exit/strategy.close calls and fire automatically whenever the order executes. For trade copying to MT5, alert_message on strategy orders is the most reliable because the alert is tied directly to the order event.

How do I send a Pine Script strategy alert to MT5?

Add an alert_message to each strategy order (entry, exit, close) containing the JSON your copier expects. Then create one alert in TradingView using the condition 'Order fills only' or 'alert() function calls only', tick 'Webhook URL', and paste your copier's webhook URL. When the strategy fires an order, TradingView posts the alert_message to MT5.

Why is my Pine Script strategy alert not firing?

The most common causes are: the alert was created with the wrong condition (use 'Order fills only' for strategy orders), the chart timeframe differs from the alert, the strategy uses calc_on_every_tick incorrectly, or the alert_message contains invalid JSON. Also confirm the alert is set to 'Once Per Bar Close' to avoid repainting and duplicate fires.