Nice, Tengo is an interesting choice.
Jingle, the wonderful dynamically customizeable relay, is back for revenge: simpler, faster, prettier, and this time with no undebuggable C library bugs, only all the other types of bugs.
Again I am looking for beta-testers: https://github.com/fiatjaf/jingle/releases/tag/v0.1.0
Discussion
Have you used it before? I couldn't find anything better.