Zap support

[callebtc]

This PR adds zap support to the LNURLp extension. It requires the nostrclient (link) extension to be installed in order to send zap receipts to nostr. Many relays should be added to nostrclient so enough people see the zaps (the zap receipts are not yet sent to the relays in the zap note, see todo).

Todo:

• [x] Admin settings: set nostr private key for zap server
• [x] Send zap_receipts to relays attached to zap
• [x] Setting to turn off zaps for a specific address
• [x] local ws vs wss (I need wss because I run uvicorn with https)

[prusnak]

Is it okay to generate a new zap pubkey every time LNbits is restarted?

I'm not saying it isn't, what I am saying is that I don't really understand why zaps are required to be signed by arbitrary key at all, if this is possible.

[callebtc]

Is it okay to generate a new zap pubkey every time LNbits is restarted?

I'm not saying it isn't, what I am saying is that I don't really understand why zaps are required to be signed by arbitrary key at all, if this is possible.

Yeah I think it's ok, nobody is checking anything anyways (there would have to be a list of certified zap servers otherwise). I've hardcoded it before and I'm planning to add some sort of setting where you can add the pk as an admin user maybe.

Have you tried the PR?

[Bashy]

What would be the downside of a user defined privkey for the zapper?

It'd allow to whitelist the zapper pubkey on some private or write restricted relays.

[callebtc]

What would be the downside of a user defined privkey for the zapper?

Nothing in particular, it would just be a setting in the interface.

It'd allow to whitelist the zapper pubkey on some private or write restricted relays.

That's a good point!

[prusnak]

I've hardcoded it before and I'm planning to add some sort of setting where you can add the pk as an admin user maybe.

Yeah, it makes sense to have the similar setting to CASHU_PRIVATE_KEY in the cashu extension to set the Zap private key.

[talvasconcelos]

Possible fix #9 ?