For idempotency keys: I want to use the Prefect templating, in conjunction with a runtime variable. Will

create_flow_run(..., idempotency_key="{date}-"+MY_VAR)

function as expected? It's hard to tell, because I don't know yet how Prefect compiles the string templating as part of tasks. Would I need to generate this string as a task result, and then pass the result to the kwarg?

Yes this needs to be a task result. Otherwise it will be evaluated during Flow build time

Thanks