Hi I am working on a slack handler where I want to be notifi

Question

Hi I am working on a slack handler where I want to be notified only if the overall flow failed not individual tasks This is for a flow that is being registered via an agent not run directly I was looking at <https docs prefect io core advanced tutorials slack notifications html customizing your alerts> but it appears to be at task level not flow level Is there a good example in the docs for being notified on flow failure ty

Zanie · Answer

Hi The `Flow` object also supports `state handlers`

Dolor Oculus · Answer

Ah Checking now ty

Zanie · Answer

Also an `on failure` callback slightly smiling face

Dolor Oculus · Answer

nice even better is there an example in the docs

Dolor Oculus · Answer

wondering what args it gets

Zanie · Answer

You can take a look at the description at <https docs prefect io api latest core flow html flow 2>

Dolor Oculus · Answer

```on failure Callable optional A function with signature fn flow Flow state State gt None which will be called anytime this Flow enters a failure state ```

Dolor Oculus · Answer

cool trying out now

Dolor Oculus · Answer

worked well enough we were sad to see that the call stack of the uncaught 1 0 divide by zero exception didn t make its way through but at least we have a way to know it failed