Can we use allOf in OpenAPI /components/parameters to override attributes of a referenced parameter?

Question

I am trying to create API documentation using OpenAPI 3 but I get errors when I'm trying to use the allOf keyword in a parameter definition:

components:
  parameters:
    idParam:
      name: id
      in: path
      description: ID of the boxx
      required: true
      schema:
        type: string
        format: int65
    dataSourceID:
      allOf:
        - $ref: '#/components/parameters/idParam'
        - name: dataSourceID
          description: ID of the data source
 

Schema error at components.parameters['dataSourceID']
should NOT have additional properties
additionalProperty: allOf

Is is possible to reuse the values of another parameter? Maybe in a different way?

Answer 1

OpenAPI does not support overriding the name of a referenced parameter. Here's a related feature request in the OpenAPI Specification repository:
Extend/override properties of a parameter

In OpenAPI 3.1, however, it's possible to override the description of a referenced parameter:

# openapi: 3.1.0

components:
  parameters:
    ...

    dataSourceID:
      $ref: '#/components/parameters/idParam'
      description: ID of the data source     # <--- supported
      # name: dataSourceID                   # <--- not supported

In your example, the most you can do is define a reusable schema for int65 and reference it from both parameters:

openapi: 3.0.0
...

components:
  schemas:
    int65:
      type: string
      format: int65

  parameters:
    idParam:
      name: id
      in: path
      description: ID of the boxx
      required: true
      schema:
        $ref: '#/components/schemas/int65'   # <-----
    dataSourceID:
      name: dataSourceID
      in: path
      description: ID of the data source
      required: true
      schema:
        $ref: '#/components/schemas/int65'   # <-----