Structured Output Prompting

Also known as: JSON mode, schema-constrained generation

Structured output prompting instructs a model to produce output conforming to a specific data schema — typically JSON — either through prompt instructions alone or through API-level schema enforcement that constrains the model's token sampling. Schema-constrained generation guarantees parseable output even when the model's instruction-following is imperfect, eliminating the need for fragile post-processing heuristics. It is essential in agentic pipelines where downstream code must reliably parse and act on model responses.