Canonical schema
One fixed set of field names and types that every source is mapped onto.
What it means
Every platform describes the same idea differently: a follower count may be followers, followers_count or nested three levels deep. A canonical schema picks one name and one type per idea and translates each source to it, so code written for one source works on the next.
How Onekey handles it
Onekey maps every endpoint onto typed groups such as author, content, engagement, media and entity. A follower count is always author.followers, a number. Types are enforced by the mapper, not trusted from the source. Anything with no shared meaning goes in ext. Each endpoint page lists exactly which fields it emits.