/summon villager ~ ~2 ~ {VillagerData:{profession:librarian,level:5,type:plains},Offers:{Recipes:[
{buy:{id:wheat,Count:12},buyB:{id:wheat_seeds,Count:12},sell:{id:wheat_seeds,Count:1,tag:
{display:{Name:"{\"text\":\"Seed Upgrade\",\"color\":\"green\"}"}},maxUses:128}}]}}