A2uiFormatException

Thrown when a payload is well-formed JSON but does not describe a valid A2UI structure.

This is a SerializationException, so a caller that already catches serialization failures catches these too.

Note that catching SerializationException is not sufficient on its own for untrusted input: neither this library nor kotlinx.serialization bounds nesting depth, so a deeply nested payload fails with a StackOverflowError — an Error, not an exception. Bound the size and nesting of a payload at the transport before handing it to A2uiJson.