gistfile1.txt

{
  "openapi": "3.0.1",
  "info": {
    "title": "My API",
    "version": "v1"
  },
  "paths": {
    "/Test": {
      "get": {
        "tags": [
          "Test"
        ],
        "responses": {
          "200": {
            "description": "Success",
            "content": {
              "text/plain": {
                "schema": {
                  "$ref": "#/components/schemas/MyType"
                }
              },
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/MyType"
                }
              },
              "text/json": {
                "schema": {
                  "$ref": "#/components/schemas/MyType"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "MyEnum": {
        "enum": [
          "Value1",
          "Value2"
        ],
        "type": "string"
      },
      "MyType": {
        "required": [
          "stringy"
        ],
        "type": "object",
        "properties": {
          "stringy": {
            "type": "string"
          },
          "integer": {
            "type": "integer",
            "format": "int32"
          },
          "myEnumValue": {
            "$ref": "#/components/schemas/MyEnum"
          }
        },
        "nullable": true
      }
    }
  }
}