Only what is in the Docs is really “official”, but @BarryCarlyon 's Examples on GitHub are generally really high-quality and I can vouch for them.
Generally, it may also be worth to note the existance of some API Endpoints that Mirror Information available via chat - like GET moderators - do note the requirement for a broadcaster/moderator token on the Endpoints, though. Also EventSub and its soon™ to be available WebSocket Transfer.
That said, chat is still a very good general source for most things - just be aware of the other potential sources in case this changes in the future.