Power Automate (WDL) function
addProperty — Power Automate (WDL) function reference
Add a field to an object.
Syntax
wdl
addProperty(object, property, value)
Examples
wdl
addProperty(item(), 'Processed', true)
→ New object
wdl
addProperty(triggerBody(), 'ProcessedAt', utcNow())
→ The trigger body with a new ProcessedAt field
wdl
addProperty(item(), 'RowNumber', variables('counter'))→ The loop item with a new RowNumber field
Common mistakes & gotchas
- Throws if the property already exists on the object — addProperty() is strictly for adding a new key; use setProperty() when the key might already be present.
- Returns a new object rather than mutating the input, so capture the output (e.g. in a Compose action) to use the enriched object downstream.
Related Workflow Definition Language functions
From Objects & JSON