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Hi, am struggling to find a standard way to handle flow state changes in Prefect 2. the state handler approach in v1 is deprecated. I need to define a decorator I assume which applies the flow and then applies some kind of state handler on top of that. Does anyone have some code samples on how to do that please?

Hi Dan,

I think notifications are what you are looking for?
<https://docs.prefect.io/ui/notifications/>

This might be something you are looking for: <https://khuyentran1401.github.io/prefect-alert/>

Right now this collection only supports alerting on failure, but we plan to support handling any states in the future

Thanks. I tried prefect-alert and it works fine when running as per the example directly from a script. However when I deploy then run with an agent the decorator is not triggered.

Also SlackWebhook uses the old incoming webhook alerts. We use messages posted via an app using the slack client so was wondering it a notification type will be created for firing messages to Slack that way

Also, in the alert_on_failure decorator, you define the block_type to be an object instance of a AppriseNotificationBlock but I believe you are expecting a class instance

And thanks <@U03FKQX1TH9> I have seen Notifications. But I was looking for a decorator much like <@U03GUVCV8DS> was referring to.

&gt; When I deploy then run with an agent the decorator is not triggered
Which version of prefect-alert are you in?

&gt; We use messages posted via an app using the slack client so was wondering it a notification type will be created for firing messages to Slack that way
You mean creating notification using something that is not a notification block?

&gt; In the alert_on_failure decorator, you define the block_type to be an object instance of a AppriseNotificationBlock but I believe you are expecting a class instance
Could you be more specific about that you mean by object instance and class instance?

```def alert_on_failure(block_type: AppriseNotificationBlock, block_name: str):```


This indicates block_type should be e.g. an instance of a SlackWebhook or similar derived class

However it actually want you to pass a class instance so SlackWebhook not SlackWebhook("my-hook-name")

So the type hint is telling you one thing but the actuality is you want a different type passed to the hint

This is highlighted nicely in PyCharm for instance

Of course doesn't stop the code from working

To fix the type hint, use:def alert_on_failure(block_type:Type[AppriseNotificationBlock], block_name: str):

Thanks for the feedback. I’ll make some changes to prefect-alert and keep you updated