Skip to main content
Code: response_format_too_large HTTP status: 400 Type: invalid_request

​
When it fires

The JSON schema you passed in response_format.json_schema exceeds the platform’s payload-size cap for structured-output schemas. Surfaced as a distinct code (vs invalid_format) so client tooling can branch on the right fix — you need to trim the schema, not the prompt.

​
How to recover

Reduce the size of the schema: drop unused properties, shorten description strings, factor repeated subschemas into $defs references. If the schema is intrinsically large, consider breaking the workload into multiple smaller calls or using a function-call (tool) shape instead.