Process Variables Change Observer/Listener

Hey Camunda Ninjas,

it would be super awesome if there would be a way to get a callback (e.g. external service task) on variable value change.

As an example.
I have variable ‘activeUser’ and would like to trigger some action if that variable changes. The change will happen using Camunda process variable change REST api.

Such request to change variable value might happen in any step of the flow. Change of the value has impact on future step but also might have on being executed now.

If I change flow to add check against variable change (with gateway) that would pollute it quite a bit and won’t have impact on currently executed step.

If there would be support for adding some kind of observers I would be able to use Camunda process variable as my storage and trigger custom action if these change. I use mostly external service tasks.

Otherwise I would need to implement custom endpoint to modify that would support it.

I don’t see anything like that is supported. How would you do it today?


Hi @camunda_sailor,

maybe you can use a conditional catch event. If the variable activeUser is updated then the conditional event is triggered.

Best regards,