Camunda Spring Boot Rest API - Propagate Detailed Informations about Exception

We are using following Setup:


  1. Angular app which communicates with Quarkus Microservice
  2. Quarkus - Microservices, gets a call which tries to complete a usertask via Camunda Rest API.
  3. Java Delegates (Camunda, Spring Boot) are executed (no saving points/ no async before - so everything in one transaction) which triggers an external System for validating data.

User sees, specific validaiton message which was given by the external system. As a result the information from the external system should be propagated to the quarkus microservice, which should propagate the infos to Angular.

Angular triggers the Quarkus Rest client. The microservices tries to complete the user task. As a result the service task/ java delegate is executed. The call in the Java Delegate returns a HTTP Status 400 with specific Information. But the Camunda (Spring Boot) Instance returns a 500 to the Quarkus microservice.

We tried to implement a ResponseEntityExceptionHandler but the code wasn’t executed. Furthermore we couldn’t find any informations in the documentation about how to throw custom exceptions/custom responses within the Camunda Api. Does anyone have an Idea whats the best approach to deliver more informations to the executer?

Thanks in advance