ApiGateway OpenApi 3.0.1 nullable properties

Question

This is my input body request

```
{
    "storeIntegrationName": "DEV STORE",
    "storeCreationDate": "2023-12-20T05:36:56-05:00",
    "storeUpdateDate": "2023-12-20T05:37:05-05:00",
    "storeReference": "8065509753074",
    "name": "The Collection Snowboard: Oxygen",
    "bodyHtml": null
}
```

i have set property nullable: true for param bodyHtml in the object body of a cloudformation Resource Type: AWS::ApiGateway::RestApi

```
        components:
          schemas:
            Article:
              type: object
              required:
              - storeIntegrationName
              - storeCreationDate
              - storeUpdateDate
              - storeReference
              - name
              properties:
                storeIntegrationName:
                  type: string
                bodyHtml:
                  type: string
                  nullable: true
                storeCreationDate:
                  type: string
                  format: date-time
                storeUpdateDate:
                  type: string
                  format: date-time
                storeReference:
                  type: string
                  nullable: true
                type:
                  type: string
                  nullable: true
                name:
                  type: string

```

ApiGateay validator response is

```
{
    "message": "Invalid request body",
    "responseType": "BAD_REQUEST_BODY",
    "validationErrorString": "[instance type (null) does not match any allowed primitive type (allowed: [\"string\"])]"
}
```

Romeo Corgiolu · Accepted Answer

Resolved using this syntax

```
bodyHtml:
  oneOf:
    - type: string
    - type: 'null'
```

Giovanni Lauria · Answer

That is a support issue....
API Gateway validator does not fully support the nullable attribute of the OpenAPI specification. While nullable: true is valid in OpenAPI, API Gateway might not interpret it correctly, causing it to expect a string value instead of allowing null.

As a workaround, you could consider changing the type of bodyHtml to an array that can contain either a string or null, like so:

```
bodyHtml:
  type: array
  items:
    type: string
  minItems: 0
  maxItems: 1
```

ApiGateway OpenApi 3.0.1 nullable properties

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