GLOSSARY
Structured Output
Making a model return valid JSON that matches your schema — the difference between a demo and software you can put in production.
Free-form text is easy to read and hard to program against. Structured output modes (JSON mode, function schemas, grammar-constrained decoding) force the model's choices at every token so the result parses — fields land where your schema says, enums stay in range, no trailing commentary. This turns LLMs into extractors and routers that other code can consume reliably.
Reliability is now high but not magical: constrained decoding guarantees valid JSON, not true JSON. A field can be validly formatted and confidently wrong, so schema design (required fields, enums, descriptions) and spot-check evaluation remain part of the job.