openapi: 3.1.1
info:
  title: OpenAPI 3.1.1 headers example
  version: 1
paths:
  /foo:
    get:
      parameters:
        - in: header
          name: Content-Type
          required: true
          schema:
            type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: string
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: string
    patch:
      parameters:
        - in: header
          name: Content-Type
          required: false
          schema:
            type: string
      requestBody:
        required: false
        content:
          application/json:
            schema:
              type: string
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: string
    post:
      parameters:
        - in: header
          name: content-type
          required: false
          schema:
            type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: string
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: string
    put:
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: string
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: string