Response headers are not visible on swagger UI

[SuhaniArora]

Q&A (please complete the following information)

• OS: Windows 11
• Browser: chrome
• Version: 134.0.6998.89
• Method of installation: https://editor.swagger.io/
• Swagger-UI version: N/A
• Swagger/OpenAPI version: OpenAPI 3.0.1

Content & configuration

I have defined a header in the response section in the following way:

responses:
      "202":
          description: Accepted
          headers:
            x-resource-id:
              description: Job objects status Id
              schema:
                type: string
          content:
            application/json:
              schema:
                type: object

If I open the network tab, I can see the below response headers:

HTTP/1.1 202 Accepted
Server: awselb/2.0
Date: Wed, 19 Mar 2025 14:06:43 GMT
Content-Type: application/json
Content-Length: 0
Connection: keep-alive
Access-Control-Max-Age: 86400
Access-Control-Allow-Methods: OPTIONS, POST, GET, PUT, DELETE
Access-Control-Allow-Headers: *
Access-Control-Allow-Credentials: true
Access-Control-Allow-Origin: *
x-resource-id: 1165

But on the swagger UI I can only see the below headers:

Describe the bug you're encountering

Described above

Expected behavior

The headers should be shown in response section

[Mircea-Exswap]

You are experiencing a CORS problem.
In CORS, there's a difference between:

• Allowed headers: What the browser can send in the request.
• Exposed headers: What the browser can read from the response in JavaScript.

For exposing all response headers (so JavaScript like Swagger UI can read them), you cannot use "*" — browsers do not support Access-Control-Expose-Headers: *.
You need something like this to be configured on your response:
Access-Control-Expose-Headers: Content-Disposition, Content-Description, Content-Length, Content-Type