xcompat/doc/stairs.md

you can use this via xcompat.stairs.register(nodename, def)

an example would be:

xcompat.stairs.register(
    "xcompat_stairs_test:fake_node",
    core.registered_nodes["xcompat_stairs_test:fake_node"]
)

if the game you are running on isnt supported (see readme), it falls back to using a polyfill. each backend adds aliases to the polyfill, mainly so that if we add a future backend that ran on polyfill, everything keeps working (yay)

at this time stairsplus/moreblocks compatibility/upgrading isnt supported, however should be added in the future. for now, in your mod code do something like the following:

if core.registered_modes("moreblocks") then
    --call stairs plus
else 
    xcompat.stairs.register(node, def)
end

that way in the future nothing will break when support is added and at your convince the first part of the if can be removed