Glossary
Structured Output
When an LLM is constrained to produce output in a strict format like JSON.
Definition
Structured output is the ability to constrain an LLM's response to a specified schema — typically JSON, but also XML, YAML, or a custom format. Modern models support this natively, using techniques like constrained decoding or fine-tuning to guarantee schema adherence.
Context
Structured output is essential for integrating LLMs into deterministic software systems. When an agent needs to call a tool, populate a database, or pass data downstream, structured output turns free-form generation into reliable machine-readable data. Modern models achieve near-100% schema conformance on well-defined schemas.