OpenAPI readonly/writeonly validation not working

[marimelon]

Using the same schema for request and response with writeOnly + required fields causes validation failures.

openapi

openapi: 3.0.3
info:
  title: Readonly writeonly test
  version: 1.0.0
paths:
  /users:
    post:
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/User'
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/User'

components:
  schemas:
    User:
      type: object
      properties:
        id:
          type: string
          readOnly: true
        name:
          type: string
          writeOnly: true
      required: [name]

scenario

desc: OpenAPI readonly writeonly validation issue
runners:
  api:
    endpoint: http://localhost:8081
    openapi3: openapi3.yml
    
steps:
  - api:
      /users:
        post:
          body:
            application/json:
              name: userName
    test: current.res.status == 200

error

Failure/Error: http request failed on "OpenAPI readonly writeonly validation issue".steps[0]: openapi3 validation error: Error: 200 response body for '/users' failed to validate schema, Reason: The response body for status code '200' is defined as an object. However, it does not meet the schema requirements of the specification, Validation Errors: [Reason: missing property 'name', Location: /required], Line: 24, Column: 7

Log

❯ runn run --scopes read:parent openapi_readonly_writeonly_issue.yml --debug
Run "api" on "OpenAPI readonly writeonly validation issue".steps[0]
-----START HTTP REQUEST-----
POST /users HTTP/1.1
Host: localhost:8081
Content-Type: application/json

{"name":"userName"}
-----END HTTP REQUEST-----
-----START HTTP RESPONSE-----
HTTP/1.1 200 OK
Content-Length: 13
Content-Type: application/json
Date: Sat, 06 Sep 2025 08:00:11 GMT

{"id":"123"}

-----END HTTP RESPONSE-----
F

1) openapi_readonly_writeonly_issue.yml 3396445fadda9df9f5e32746a5ddd9d81bc9ee10
  Failure/Error: http request failed on "OpenAPI readonly writeonly validation issue".steps[0]: openapi3 validation error: Error: 200 response body for '/users' failed to validate schema, Reason: The response body for status code '200' is defined as an object. However, it does not meet the schema requirements of the specification, Validation Errors: [Reason: missing property 'name', Location: /required], Line: 24, Column: 7
  -----START HTTP REQUEST-----
  POST /users HTTP/1.1
  Host: localhost:8081
  Content-Type: application/json
  
  
  -----END HTTP REQUEST-----
  -----START HTTP RESPONSE-----
  HTTP/1.1 200 OK
  Content-Length: 13
  Content-Type: application/json
  Date: Sat, 06 Sep 2025 08:00:11 GMT
  
  {"id":"123"}
  
  -----END HTTP RESPONSE-----
  Failure step (openapi_readonly_writeonly_issue.yml):
   8   - api:
   9       /users:
  10         post:
  11           body:
  12             application/json:
  13               name: userName
  14     test: current.res.status == 200


1 scenario, 0 skipped, 1 failure

[k1LoW]

@marimelon Thank you for your report!

There is an open issue in the validator package that runn is using.

ref: pb33f/libopenapi-validator#90