Json

JSON-shaped response. schemaJson is the JSON-Schema constraint (optional — null means "any valid JSON object"); schemaName and schemaDescription are passed verbatim to providers that expose named-schema modes (OpenAI structured outputs, Gemini's response_schema).

Idiomatic use via outputObj / outputArray: when a caller wants typed output, they construct an Output AND set responseFormat = ResponseFormat.Json(...) on the call params so the provider constrains decoding, then Output.decode parses the response text.