Description
components.headers stores reusable header definitions. Defining a header there does not add it to a response; reference it where it is needed.
Potential impact
Readers may expect a header that the response does not contain, while maintainers keep unnecessary definitions.
Remediation
Use $ref at the actual location, such as a response’s headers, and match the name and schema to the real header. Check external use before removing unnecessary definitions.
Examples
These examples connect X-Pages in the response’s headers to the shared xPages definition.
Before
json
{
"openapi": "3.0.0",
"info": {
"title": "Simple API Overview",
"version": "1.0.0"
},
"paths": {
"/": {
"get": {
"operationId": "listVersionsv2",
"summary": "List API versions",
"responses": {
"200": {
"description": "success",
"content": {
"application/json": {
"schema": {
"type": "array",
"items": {
"$ref": "#/components/schemas/MyObject"
}
}
}
}
}
}
}
}
},
"components": {
"schemas": {
"MyObject": {
"type": "object",
"properties": {
"id": {
"type": "string"
},
"name": {
"type": "string"
}
}
}
},
"headers": {
"xPages": {
"schema": {
"type": "integer",
"description": "number of pages"
}
}
}
}
}
After
json
{
"openapi": "3.0.0",
"info": {
"title": "Simple API Overview",
"version": "1.0.0"
},
"paths": {
"/": {
"get": {
"operationId": "listVersionsv2",
"summary": "List API versions",
"responses": {
"200": {
"description": "success",
"content": {
"application/json": {
"schema": {
"type": "array",
"items": {
"$ref": "#/components/schemas/MyObject"
}
}
}
},
"headers": {
"X-Pages": {
"$ref": "#/components/headers/xPages"
}
}
}
}
}
}
},
"components": {
"schemas": {
"MyObject": {
"type": "object",
"properties": {
"id": {
"type": "string"
},
"name": {
"type": "string"
}
}
}
},
"headers": {
"xPages": {
"schema": {
"type": "integer",
"description": "number of pages"
}
}
}
}
}