Requirements change, but API contracts are forever - I wish! A breaking change is something that is not backwards compatible. This means that a consumer of your API would not be able to use the new version without making a code change themselves. We avoid breaking changes if possible, but there are cases when they are inevitable. It could be something small: like making a mandatory field optional. Or it could be something big: like removing a query or a mutation. In this talk we'll review the types of breaking changes you may encounter and how to deal with them gracefully.
Handling Breaking Changes in GraphQL
From:

GraphQL Galaxy 2022