Review unsupported schema keywords

Preserve the contract while choosing where unsupported behavior is enforced.

Match the finding

These titles and messages come from this local checker. They are not AWS service error quotes.

Schema readOnly is unsupported
Schema discriminator is unsupported
Schema default is unsupported
Schema exclusiveMinimum is unsupported

Cause and scope

The checker flags readOnly, discriminator, default, and exclusiveMinimum because API Gateway REST does not support these schema keywords. They remain unchanged in the source and repaired output.

What to do

Review each reported keyword in context. Test request/response visibility for readOnly, subtype selection for discriminator, application defaulting for default, and boundary values for exclusiveMinimum.

Find which requests, responses, or generated clients depend on the reported keyword.
Document and implement the intended behavior in an appropriate validation or application layer.
Test the affected cases after import before deciding whether any schema change is acceptable.

Schema fragment: boundary behavior needs a test

type: number
minimum: 0
exclusiveMinimum: true

The declared boundary excludes zero. Test zero and a positive value against the actual imported validation and backend behavior; removing exclusiveMinimum changes the declared constraint.

Avoid a misleading fix

Do not delete every unsupported keyword as a cleanup step. Do not assume an imported model, generated client, and backend interpret these fields identically.

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Related findings

Sources and scope

Scope: this local checker, API Gateway REST APIs, and OpenAPI 3.0. Guidance reviewed 4 October 2026. A passing check does not guarantee import or runtime behavior.