Or go around asking did you send me some monero ? Hehe 🙃

my project is split in half at the moment. The old system with working monero payments relies on people trusting me with primary address and view-key and that data is stored in a database bound to the persons npub until they update or delete it. When someone tips the profile they're basically drafting a secret event post to the receiver. You can include whatever you want in that secret p2p event. When you tip the profile you can include a message, if you tip a post it includes it as a quote and attached is the amount and who sent it, payment must be detected in for the secret p2p event to actually be sent to the receiver.

The newer system which isn't working because i'm learning how to make it work gets rid of the backend server database and has everything work with a bot. When you save your view only wallet data instead of being put in a central server it giftwraps the event like a contract between the bot and user, no one else can see it and theres no central server, its being transmitted over nostr in giftwrapping. Then basically the same process as the first.

In both cases I have the view-keys and can technically see all incoming transactions to the wallets and know whose receiving wallet is which npub but who sent it? no idea, did they leave a message? no idea, did they tip a specific post? no idea.

yes today the only way to know is using subaddresses or integrated addresses, but the client will only know about the payment if they have your viewkey, a-lá xmrchat.com

another way would be the sender publishing a zap type of note with the txid and the secret tx key which proves a payment for everyone on nostr to see, but that requires implementing a wallet in the client and sending only through that nostr app's wallet

with fcmp around the corner it will be possible to use outgoing view keys for nostr instead (timestamped explainer: https://youtu.be/prNvJWILkoI?t=957 ), or use the new CARROT addresses with a payment-validator-only viewkey tier instead of (docs: https://github.com/jeffro256/carrot/blob/a17bd68a842cca984c9e40b4bf9ea3b17176116c/carrot.md#223-payment-validator-tier )

personally for now I will focus only on tips (people can just send monero around addresses, nothing published on nostr and no viewkey or wallet integration) until the FCMP upgrade, which then will enable way more exploration

Correct. The QR method for nosmero that was implemented preserves the inherent privacy by not running a backend database or requiring users to share anything that is either potentially identifying or requires server-side protection. Only the recipient knows what note was zapped and the amount. It would be great to see stats given the social aspect of nostr but, hey, it's monero, stuff is hidden away