Why Structured Output

Natural-language LLM output is ambiguous to parse. A model may answer The price is $42 one time and It costs forty-two dollars the next. Downstream code that expects a number breaks.

Structured output means constraining the model to emit data in a machine-readable shape (JSON, typed objects) so that parsing is deterministic, not heuristic.

Teams often spend more engineering effort on post-processing brittle text than on prompting. Regex extraction, fuzzy string matching, and retry-on-parse-fail loops are symptoms of unstructured output.

• Regex breaks when phrasing shifts.
• Fuzzy matching introduces silent errors.
• Each new field multiplies parsing surface area.

Structured generation moves this contract upstream into the request.