The FME Server API supports publishing notifications to FME Server. Notification messages consist of a topic and a body.
Topics define how the publisher and subscriber should communicate. At a high level, it is an agreement between the publisher and subscriber. Subscribers can be configured in specific ways to perform specific operations for specific topics. Publishers can publish notification messages with specific content for specific topics. It’s important to have Subscribers and Publishers configured appropriately so they both communicate each other in the expected way for a given topic.
For example, the handling of success and failure topics via the Email Subscriber could be different. For success, this might mean the original requester is sent an email that their transformation was successful. For failure, it might mean the original requester is sent an email that their transformation failed and in addition send an FME Server administrator an email with error information for troubleshooting.