I want to update tickets using a trigger or automation. The ticket attributes I want to update are not accessible using business rules. I can make the update successfully using the Support API. Can I have the trigger or automation notify a target that updates the ticket through the API?
No, this workflow is not recommended or supported. When a ticket is updated by business rules and the API simultaneously, errors are likely to occur. When this happens, it is called a race condition.
Every time a ticket is created or updated, all your business rules run in a cycle against that ticket. For instance, triggers fire and update the ticket if their conditions are met during the cycle. A cycle is the entire process of a ticket being checked against all your triggers. For more information, see the article: How do triggers run according to their position on the trigger page?
When a trigger updates a ticket using the API, the update occurs at some indeterminate point in the cycle. Results can vary based on when the ticket update occurs in the cycle. The ticket update can affect whether other business rules fire.