WebFetch UserAgent identifies as user, not as agent / bot

[pdehne-steidle]

Description

The WebFetch tool in OpenCode sends Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36 as its user agent.

I think this is wrong, in my view it impersonates as a human. Instead it should send an user agent that allows the request to be identified coming from OpenCode.

For example OpenAI sends Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko); compatible; ChatGPT-User/1.0; +[https://openai.com/bot"](https://openai.com/bot%22). This allows for websites to decide what to do with traffic from ai agents.

Plugins

No response

OpenCode version

1.2.9

Steps to reproduce

Fetch any url using the WebFetch tool and inspect the log files of the webserver.

Screenshot and/or share link

No response

Operating System

No response

Terminal

No response

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• [FEATURE]: Allow overriding WebFetch tool’s User-Agent header #9013: [FEATURE]: Allow overriding WebFetch tool's User-Agent header — this feature request covers the same component and concern (WebFetch sending a browser-like User-Agent). Your issue frames it as a bug (impersonation), while [FEATURE]: Allow overriding WebFetch tool’s User-Agent header #9013 is a feature request for overriding the header, but they address the same underlying problem.

If your issue is distinct (e.g., you specifically want the default changed rather than just an override option), please clarify the difference so maintainers can link or merge appropriately.

[pdehne-steidle]

Your issue frames it as a bug (impersonation), while [FEATURE]: Allow overriding WebFetch tool’s User-Agent header #9013 is a feature request for overriding the header, but they address the same underlying problem. If your issue is distinct (e.g., you specifically want the default changed rather than just an override option), please clarify the difference so maintainers can link or merge appropriately.

I indeed think this is a bug. OpenCode by default should send an user agent that allows for identifying requests as coming from OpenCode. Allowing users to overwrite the default is a separate issue in my opinion.

[github-actions]

To stay organized issues are automatically closed after 60 days of no activity. If the issue is still relevant please open a new one.