Got it! So you can make the entire HTTP endpoint a DBOS workflow that performs the synchronous work then launches a background task. Something like this:

    @app.get("/endpoint")
    @DBOS.workflow()
    def http_workflow():
        synchronous_task() # Run the synchronous task
        DBOS.start_workflow(background_task) # Start the background task asynchronously

This is atomic in the sense that if the synchronous task runs, the background task will always also run.