Expression Builder is an advanced Automate node for conditions that depend on calculations, relationships between values, or data from one or more sources. Its data and calculations are evaluated again whenever its parent condition checks.

Use it when the condition must remain live rather than capture one fixed value.

When should I use Expression Builder?

Use Expression Builder when your strategy needs to:

• Recalculate a value whenever the condition is checked.
• Combine values from multiple data sources.
• Perform arithmetic before making a comparison.
• Calculate an average, highest value, lowest value, total, or count.
• Rank a series and retrieve another value from the corresponding row.
• Monitor a value that changes during the workflow.

Examples include:

• Recalculate the average of the previous 20 candles every five minutes.
• Continuously calculate the combined CE and PE premium.
• Find whichever option currently has the highest OI.
• Compare current P&L with a threshold.
• Compare live LTP with another calculated value.

When is a normal Automate node enough?

Use a normal node when it directly supports the exact condition you want.

For example:

“Alert when RELIANCE LTP is above ₹3,000.”

A normal price check can handle this fixed threshold. Expression Builder is not required.

Use Expression Builder when the condition itself requires a calculation or relationship that a standard node does not directly represent.

How does Expression Builder evaluate data?

Expression Builder keeps its data source values, selections, and calculations live.

For example, if you use the previous 20 candles, that window can move as new completed candles become available and the condition is checked again.

Example: Rolling volume condition

“Every five minutes, check whether the current volume is more than twice the average of the previous 20 candles.”

Because both the candle window and current volume need to remain current, Expression Builder is the appropriate choice.

What If?