Structured Outputs

Benched.ai Editorial Team

Structured outputs are model responses formatted as JSON, XML, or other machine-parseable schemas instead of free-form text.

Schema Design Elements

Element	Purpose	Example
Type name	Identify structure	`ProductReview`
Required fields	Ensure completeness	`title`, `rating`
Enum constraints	Limit values	`rating` ∈ 1-5
Nested objects	Capture hierarchy	`author.name`

Benefits

Deterministic parsing for downstream services.
Reduced prompt-parsing errors.
Easier validation and analytics.

Challenges

Generates longer token sequences due to braces and quotes.
Risk of format violations (missing comma) if prompt not specific.
Strict schemas can limit creative phrasing.

Current Trends (2025)

OpenAI function-calling enforces JSON via tool spec.
JSON-Schema validation in SDKs rejects invalid completions before returning¹.

Implementation Tips

Wrap schema description in triple backticks within prompt.
Ask model to repeat schema in the output header for self-check.
Use streaming parsers to validate partial JSON as it arrives.

JSON Schema Draft 2025-01. ↩