Good point. SENDING would be much safer and easier to implement. I want to study CoinOs' implementation first. I just checked the CoinOs web interface, and I don't yet see a way to send a keysend using that... so maybe it is NWC only? In that case.. can you recommend which applications that users would typically be using to send these keysend payments (presumably they have NWC support?)
NWC seems to be the way to go. It's been working great for me using albyhub as a proxy to my node.
If you can ever get the receiving part of keysend that would be great also. Alby has code for it in it's repo (somewhere)
Basically you use a customKey and customValue
The payments go to one node. The customKey and customValue tell you the node runner which "account" the payment belongs to.
I haven't tried it yet but I believe this is also how lnbits does it.
Receiving is a harder problem, so getting sending to work first makes the most sense.
Again, Thank You For Your Courage! 🙂