[Windows] Website preview selects loopback proxy URL from inline code over explicit Markdown link

What version of the Codex App are you using?

26.915.3509.0

What subscription do you have?

ChatGPT Pro (planType: prolite)

What platform is your computer?

Microsoft Windows 11 x64, version 10.0.26200, build 26200

Model

GPT-5 family in Codex Desktop. The exact backend model slug was not exposed in the conversation UI, so I am not guessing a more specific identifier.

What issue are you seeing?

Codex Desktop automatically appends a generic Website Preview card to an assistant response when the response contains a loopback proxy endpoint formatted as inline code.

The same response also contained an explicit Markdown link to public OpenAI documentation. However, clicking the generated preview card opened the loopback proxy endpoint instead of the explicit public documentation link.

The loopback endpoint was an HTTP proxy entry point used by software on a remote SSH host. It was not a website and was never intended to be opened in a browser. On the Windows computer, that loopback address refers to the local computer, where no web server was listening.

The behavior repeated when a later assistant response quoted the loopback endpoint again while explaining the problem: another misleading Website Preview card was generated.

What steps can reproduce the bug?

1. Use Codex Desktop on Windows.

2. Ask Codex to help configure a proxy for a remote development host.

3. Have an assistant response contain a loopback proxy URL in inline code, for example:

   http://127.0.0.1:<PORT>/
   

4. In the same response, include an explicit Markdown link to a public documentation page.

5. Observe that Codex Desktop appends a generic Website Preview card.

6. Click the preview card.

7. The card opens the loopback proxy URL rather than the explicit public Markdown link.

8. Send another response that quotes the loopback URL in inline code; the misleading card can be generated again.

No account identifiers, remote hostnames, real ports, credentials, tokens, or local user paths are required to reproduce this.

What is the expected behavior?

• Do not create Website Preview cards for URLs inside inline-code spans or fenced code blocks.
• Do not treat loopback, localhost, private-network, or proxy endpoint URLs as normal website-preview candidates.
• If a response contains an explicit Markdown link to a public site, prefer that explicit link over URL-like text found elsewhere in the message.
• Display the actual target hostname on any generated preview card so the destination is not ambiguous.
• If there is no safe public preview candidate, do not append a Website Preview card.

Additional information

Root-cause hypothesis based on the repeatable UI behavior: the preview candidate extractor scans URL-like strings from rendered or raw assistant message content without excluding inline code or loopback targets, and its candidate ordering can take precedence over an explicit Markdown link.

The remote proxy configuration itself did not modify the Codex Desktop app's proxy settings. It was configured only in a remote VS Code Machine setting. Its relevance is that it caused a loopback proxy URL to appear in the assistant response. This makes the issue look proxy-triggered, but the likely fault is message URL extraction and preview selection rather than network routing.

There is also a safety/usability concern: the generated card encourages users to open a local service or proxy endpoint as though it were a normal website. It is unknown whether the app attempts metadata fetching for the loopback target; this report only confirms the visible card and click destination.

A screenshot exists but is omitted from the public report to avoid accidental PII. A redacted screenshot can be supplied if maintainers request it.

No implementation file or test is named. Start by reproducing the Windows Codex Desktop response with a loopback URL in inline code and an explicit public Markdown link, then locate the Website Preview candidate extraction and selection entry points. Done means code-formatted and private or loopback URLs are excluded, explicit public links are preferred, and unsafe candidates produce no preview card.