Infinite Trading is a minimalistic mod which prevents villager trades from locking up, making them always available and allowing infinite trading. I'm not sure where they get the items from, but as long as emeralds are involved they'll find a way. The wandering trader is supported and enabled by default. This can be turned off in the config.
All available config options:
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wanderingTraderInfiniteTrades default true
When enabled, the trades of the wandering trader will never lock up.
villagerInfiniteTrades default true
When enabled, the trades of villagers will never lock up.
You can buy as many items as you want:

You may freely use this mod in any modpack, as long as the download remains hosted within the CurseForge or Modrinth ecosystem.
Serilum.com contains an overview and more information on all mods available.
For issues, ideas, suggestions or anything else there is the Github repo. Thanks!

