openapi-changes MWE

spec_new.json

{
  "openapi": "3.1.0",
  "info": {
    "title": "API Reference",
    "version": "1.0",
    "description": "foo bar"
  },
  "servers": [
    {
      "url": "https://api.example.com",
      "description": "Production API"
    }
  ],
  "paths": {
    "/items/{item_id}": {
      "get": {
        "summary": "Fetch item",
        "description": "This endpoint returns an item identified by its item_id.",
        "operationId": "fetch-item",
        "parameters": [
          {
            "required": true,
            "style": "simple",
            "schema": {
              "type": "string"
            },
            "name": "item_id",
            "in": "path"
          }
        ],
        "responses": {
          "200": {
            "description": "OK",
            "headers": {},
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Item"
                }
              }
            }
          },
          "404": {
            "description": "Not Found",
            "headers": {},
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/404Error"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "Item": {
        "properties": {
          "id": {
            "type": "string",
            "title": "Id"
          }
        },
        "type": "object",
        "required": [
          "id"
        ],
        "title": "Item"
      },
      "404Error": {
        "oneOf": [
          {
            "$ref": "#/components/schemas/ResourceNotFoundError"
          },
          {
            "$ref": "#/components/schemas/FeatureNotAvailableError"
          }
        ],
        "title": "404Error"
      },
      "ResourceNotFoundError": {
        "properties": {
          "type": {
            "type": "string",
            "const": "https://docs2.example.com/reference/error-responses#404-resource-not-found",
            "title": "Type"
          },
          "status": {
            "type": "integer",
            "const": 404,
            "title": "Status"
          },
          "detail": {
            "oneOf": [
              {
                "type": "string"
              },
              {
                "type": "null"
              }
            ],
            "title": "Detail"
          },
          "title": {
            "type": "string",
            "title": "Title"
          }
        },
        "type": "object",
        "required": [
          "type",
          "status",
          "title"
        ],
        "title": "ResourceNotFoundError"
      },
      "FeatureNotAvailableError": {
        "properties": {
          "type": {
            "type": "string",
            "const": "https://docs2.example.com/reference/error-responses#404-feature-not-available",
            "title": "Type"
          },
          "status": {
            "type": "integer",
            "const": 400,
            "title": "Status"
          },
          "detail": {
            "oneOf": [
              {
                "type": "string"
              },
              {
                "type": "null"
              }
            ],
            "title": "Detail"
          },
          "title": {
            "oneOf": [
              {
                "type": "string"
              },
              {
                "type": "null"
              }
            ],
            "title": "Title"
          }
        },
        "type": "object",
        "required": [
          "type",
          "status"
        ],
        "title": "FeatureNotAvailableError"
      }
    }
  }
}

spec_prod.json

{
  "openapi": "3.1.0",
  "info": {
    "title": "API Reference",
    "version": "1.0",
    "description": "foo bar"
  },
  "servers": [
    {
      "url": "https://api.example.com",
      "description": "Production API"
    }
  ],
  "paths": {
    "/items/{item_id}": {
      "get": {
        "summary": "Fetch item",
        "description": "This endpoint returns an item identified by its item_id.",
        "operationId": "fetch-item",
        "parameters": [
          {
            "required": true,
            "style": "simple",
            "schema": {
              "type": "string"
            },
            "name": "item_id",
            "in": "path"
          }
        ],
        "responses": {
          "200": {
            "description": "OK",
            "headers": {},
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Item"
                }
              }
            }
          },
          "404": {
            "description": "Not Found",
            "headers": {},
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/404Error"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "Item": {
        "properties": {
          "id": {
            "type": "string",
            "title": "Id"
          }
        },
        "type": "object",
        "required": [
          "id"
        ],
        "title": "Item"
      },
      "404Error": {
        "oneOf": [
          {
            "$ref": "#/components/schemas/ResourceNotFoundError"
          },
          {
            "$ref": "#/components/schemas/FeatureNotAvailableError"
          }
        ],
        "title": "404Error"
      },
      "ResourceNotFoundError": {
        "properties": {
          "type": {
            "type": "string",
            "const": "https://docs.example.com/reference/error-responses#404-resource-not-found",
            "title": "Type"
          },
          "status": {
            "type": "integer",
            "const": 404,
            "title": "Status"
          },
          "detail": {
            "oneOf": [
              {
                "type": "string"
              },
              {
                "type": "null"
              }
            ],
            "title": "Detail"
          },
          "title": {
            "type": "string",
            "title": "Title"
          }
        },
        "type": "object",
        "required": [
          "type",
          "status",
          "title"
        ],
        "title": "ResourceNotFoundError"
      },
      "FeatureNotAvailableError": {
        "properties": {
          "type": {
            "type": "string",
            "const": "https://docs.example.com/reference/error-responses#404-feature-not-available",
            "title": "Type"
          },
          "status": {
            "type": "integer",
            "const": 400,
            "title": "Status"
          },
          "detail": {
            "oneOf": [
              {
                "type": "string"
              },
              {
                "type": "null"
              }
            ],
            "title": "Detail"
          },
          "title": {
            "oneOf": [
              {
                "type": "string"
              },
              {
                "type": "null"
              }
            ],
            "title": "Title"
          }
        },
        "type": "object",
        "required": [
          "type",
          "status"
        ],
        "title": "FeatureNotAvailableError"
      }
    }
  }
}