How to make a field in a definition required for some operations and not others

Question

I\'m writing my swagger definition in yaml. Say I have a definition that looks something like this.

paths:
  /payloads:
    post:
      summary: create a pay         


        

Answer 1

My way to go about this is to define an 'abstract' model which contains all the parameters. Then for each usecase, I will define a model that references the first one and indicates exactly what are the required fields.

paths:
  /payloads:
    post:
      summary: create a payload
      ...
      parameters:
      - in: body
        name: payload
        description: New payload
        required: true
        schema:
          $ref: "#/definitions/NewPayload"
    put:
      summary: update a payload
      ...
      parameters:
      - in: body
        name: payload
        description: Updated existing payload
        required: true
        schema:
          $ref: "#/definitions/UpdatePayload"
...
definitions:
  # This payload would be used with update requests and has no required params.
  NewPayload:
     allOf:
       - { $ref: '#definitions/PayloadProperties }
       - type: object

  # This payload would be used with update requests and require an id param.
  UpdatePayload:
     allOf:
       - { $ref: '#definitions/PayloadProperties }
       - type: object
         required: [id]

  PayloadProperties:
    properties:
      id:
        type: string
      someProperty:
        type: string
      ...

I find this method rather clean as it doesn't require duplication, provides seperation of concerns and granularity.