Concepts
Concepts
The mental models you need to read SDK code without surprises. One page per non-obvious thing.
If the Quickstart gets you running, this section gets you fluent. Each page is short and answers one question:
The bridge
What `MiniAppClient` actually wraps, and why your code never touches it directly.
Calling your backend
The `callApi()` mental model. Why it isn't `fetch()`. How the host's allow-list works.
Error model
Seven errors. Two failure shapes. One decision flow.
These pages don't replace the reference — they're the prose your IDE's hover tooltips can't show.