Structured output

Model output constrained or requested to follow a machine-readable schema with defined fields, types, and allowed values.

Provider-enforced schema modes can guarantee some syntactic properties, while prompt-only formatting offers weaker control. A valid object can still contain wrong entities, unsupported values, or semantically inconsistent fields. Tables and lists are visually structured but are not necessarily stable machine contracts.

Builder example

When one step's output feeds another step automatically, free-form prose breaks the chain because the next step cannot reliably find the piece it needs. If your agent extracts an order and the reply says "the customer wants two of item 5512 shipped Friday," downstream code has to guess where the quantity ends and the date begins. Tell the model to return labeled fields for quantity, item, and ship date, give it one filled-in example, and the next step reads each value by name instead of parsing a sentence.

Common confusion: Asking for a format in plain words helps, but it does not guarantee the model returns valid, parseable data every time. What makes output dependable is constraining the response to a declared schema and validating it, so a stray sentence or a missing field is caught before the next step runs on bad input.