Skip to main content



This rule belongs to the openapi-v3-standards-validation ruleset and states that:

The prefixItems property in a Schema Object helps validate each data instance against a subschema based on its position in the list. Therefore, if declared, it must contain at least one subschema in its list i.e. the prefixItems array must not be empty.

Maximum SeverityError
MessageSchema Object prefixItems list is empty.
Rule SystemSemantic
Broad CategorySchemas
Products ImpactedAPI Transformer, Code Generation, Developer Experience Portal
Tagsopenapi3 openapi standards semantic validation prefix items items json schema schema

Suggested Fixes

  • Ensure that the prefixItems list contains at least one subschema.
  • If the prefixItems list in the Schema Object is not expected to contain any subschemas, remove its declaration from the Schema Object.

For More Information