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I'm trying to send out notifications when a flow fails by defining a callback setting the flow's `on_failure` to it. The callback has (according to the docs) the following signature
```def f(obj: Union[Task, Flow], state: State) -&gt; None:```
My quest is this: how to identify the failed task from the (Flow) obj.  I see I can iterate over the flows' tasks, I'm just not sure how to identify the task's state

and, as a follow-up question, is there a way to globally set the flow's on failure to that callback, or do I have to manually modify every flow?

Hey <@U02A2MYGML0>, the states are not kept in the state handler so you need to query the FlowRun with the GraphQL API. The <https://docs.prefect.io/api/latest/backend/flow_run.html#flowrunview|FlowRunView> might help with this

You’d need to make your own Flow Class that subclass our Flow class I think