Should we add hooks?

[andreivladbrg]

A useful feature for lockup streams is the hooks.

In the context of open-ended, I personally believe they wouldn't be that helpful since:

• the product is oriented towards the sender
• we don't have NFTs

I am opening this discussion to see if you have other opinions.

@sablier-labs/solidity

[PaulRBerg]

I disagree. I think that hooks would be helpful.

• A recipient may want to be notified when a sender tops up their negative balance stream
• A sender may want to know when a recipient claims their token, e.g. for market sentiment analysis purposes

P.S. why don't we have NFTs?

[razgraf]

I've opened #34 for the NFT question.

[PaulRBerg]

cheers

[andreivladbrg]

Hmm, let's brainstorm more about the possibilities before we make a final decision.

What are the functions you have in mind for adding the hooks, and for whom? (e.g. in the deposit function run only the recipient hook)

[PaulRBerg]

Could you take a stab at designing a spec yourself?

[smol-ninja]

A recipient may want to be notified when a sender tops up their negative balance stream
A sender may want to know when a recipient claims their token, e.g. for market sentiment analysis purposes

Ain't these two "events" based notifications? I don't understand how hooks are exactly useful here.

However, I think hooks can have other use cases such as cross-contract actions. For examples,

• Some sort of reward calculation when a recipient withdraws from the stream.
• The sender implements a hook to top up the stream by checking the amount every time a recipient withdraws.

There could be many more that I can't anticipate right now but hooks are powerful features.

As for the design:

• onStreamWithdrawn on both Sender and Recipient
• onStreamCancel on Recipient
• onStreamRefund on Recipient
• onAdjustRarePerSecond on Recipient

Any thoughts on above hook endpoints? If we agree, I will create issues.

[PaulRBerg]

The point is to get notified on-chain, e.g., have a Safe multisig immediately respond to an action performed in a stream. I agree that the demand for this should be relatively little, though.

other use cases such as cross-contract action
...
hooks are powerful features.

Indeed!

Any thoughts on above hook endpoints?

I am not familiar with the API (yet), but the list sounds goods to me.

[smol-ninja]

Cool. I will create the issue for now. We can always change it later before the first release.

[smol-ninja]

Issue:

• Add Sender and Recipient hooks #45

[andreivladbrg]

I changed my mind, we should have hooks.

[PaulRBerg]

my favorite words

[andreivladbrg]

haha 😅