Basic dotnet web api following the specs from https://github.com/lnproxy/spec and the OG implementation at https://github.com/lnproxy/lnproxy-relay .
From a development perspective I wanted learn more about Hodl Invoices. I saw a demo on the use of ln proxy relays for privacy by OpenNoms while I was at the Adopting Bitcoin conference in El Salvador 2022. The idea of a proxy relay was intriguing and took led me to want create an implementation of my own.
No Dockerfile yet, but if you have an install of dotnet 7 run dotnet build and dotnet run. This will bring up the app with swagger UI at https://localhost:7290/swagger/index.html, or you could do some curl using the following example.
curl --header "Content-Type: application/json" \
--request POST \
--data '{"invoice":"<bolt11 invoice>"}' \
https://localhost:7290
I have not yet run this in a production environment, so exposing over tor or production is completely up to you if you run it in that situation. I'll flesh out details in the future if I take this project in that direction.
I think something like this would benefit from more infrastructure for monitoring invoice state and recovering after startup/failures. Basically I think there might be an off chance for loss of funds in the event that the invoice that's been wrapped was paid, but the hodl invoice has not yet settled. A small SQL Lite DB might be appropriate and could do a lot for recovery. Just some thoughts at this point.