This mod basically allows you to use CraftTweaker or config to set anvil repairing of any item with any material. Each material unit will repair 25% of durability, like in vanilla.
If you define a repair recipe for item which already has one, both will be valid (original and added one).
Example
import mods.vanillaanvilrepair.addRepairEntry;
var ingots = <minecraft:gold_ingot> | <minecraft:iron_ingot>;
//addRepairEntry(IIngredient repairedItems, IIngredient materials)
addRepairEntry(<minecraft:bow>, ingots);
This ZenScript code will allow minecraft bow to be repaired by either iron or gold ingot.
Config
# List of repairs, in format
# repaireditem1,repaireditem2[...];material1,material2[...]
# (you can use ore:item for OreDictionary entry (only for materials))
S:repairList <
>
# If true, repairs added by this mod increase further work level cost (same as vanilla)
B:repairsIncreaseCost = false