Generating missing vector tiles on the fly

I cant find any examples or interface in the tile servers I have looked at to generate tiles when missing.

This seems like an obvious approach. I can easily hack one of several nice tile servers on npm to do this, but I am surprised there isnt an interface anywhere for what to do if the tile is missing, with the option to bake it on the spot.
I will of course endeavour to have the tiles ready and waiting, my generation is intended to be fast enough to use on demand. Getting the server to trigger generation would give me a handy interface to request them to be built, and of course mean I can browse the data immediately even if I’ve triggered hours worth of prints and reprints.

Is anyone aware of a server where you can plug in a method to bake the tiles if they are missing or under other conditions, so I guess we need an examine and a generate call back,

ok, i am reading all about tilelive.
i need the mbtiles plugin I thnk