Skip to main content
Use this page when you need exact structured-output terminology and types rather than the task-first usage guide.

​
Core types

​
Request-side controls

Provider adapters compile the normalized schema before extraction. Strictness is a provider-lowering request; local JSON Schema validation still runs before Meerkat accepts the result.

​
Result-side fields

Provider schema compilation happens before the main output is saved into the result. A compilation failure can therefore return the typed extraction failure with an empty RunResult.text; output retention applies to failures after schema compilation succeeds.

​
Event ordering

After provider schema compilation succeeds, a schema-bearing run has two terminal observability stages:
  1. The normal agentic turn completes and emits run_completed with extraction_required: true. result is the main assistant output.
  2. Extraction emits exactly one follow-up terminal event: extraction_succeeded with structured_output and optional schema_warnings, or extraction_failed with last_output, attempts, and reason.
Extraction does not emit ordinary text or turn_completed events. Extraction failure does not emit run_failed; the main run already completed, and the returned RunResult carries extraction_error. Provider schema compilation happens before these success-shaped boundaries. A compile failure emits extraction_failed directly and emits neither turn_completed nor run_completed first.

​
Validation note

Schema validation depends on the jsonschema feature. A build without that feature fails closed with typed InvalidOutputSchema when an output schema is configured. Meerkat never marks merely parsed, unvalidated JSON as structured output. Each extraction attempt runs with no tools and temperature 0.0. Markdown code fences are stripped before parsing. A provider may wrap a named root object in the schema name; Meerkat unwraps that envelope only when the inner object is a clearly better match and the wrapper key is not itself declared by the schema.

​
See also