Structured Outputs
also: JSON mode · constrained decoding
Forcing model output to match a schema — the difference between text you parse and data you trust.
Structured outputs make the model emit valid JSON matching a supplied schema, either by constrained decoding (masking tokens that would break the grammar) or by strict validation and retry. This is the backbone of reliable pipelines: tool calls, extraction, classification, anything a program consumes downstream. If code parses model output with regexes, you wanted structured outputs.