Give your agent a four-step workflow: timezone → browser language → WebRTC / proxy → DNS. Record the baseline, change one setting at a time, then verify and keep a recovery path.
For macOS, Chromium browsers and Mihomo / Clash Verge Rev. Other clients need their own configuration syntax. The skill instructions are in Chinese; the agent can explain results in your preferred language.
The archive contains claude-environment-check/SKILL.md, with no automatic installer. Read the full instructions first ↗
What the four steps cover
- Timezone: compare OS and browser values, record the original settings and verify any change by reading them back.
- Language: inspect the actual preference list and locale; adjust them only to match your needs.
- WebRTC and proxies: distinguish system proxies, app settings and TUN routing; compare ICE candidates and exits, and check real-time communication.
- DNS: inspect OS, client and browser resolver paths. Includes a Mihomo merge example that must be adapted to your existing proxy group, with backup, verification and rollback.
Use the skill
- Download and extract the ZIP to obtain the
claude-environment-checkfolder. - Codex: place the file at
~/.agents/skills/claude-environment-check/SKILL.md. Select the skill or mention$claude-environment-check. - Claude Code: place it at
~/.claude/skills/claude-environment-check/SKILL.md, then enter/claude-environment-check. - Start with the request below and decide on changes after reviewing the findings. If downloads are unavailable in your current browser, open this page in your system browser.
Use claude-environment-check to inspect my timezone, browser language, WebRTC, proxy and DNS settings. Report evidence, recommendations and rollback steps. Inspect only for now; do not modify system settings.
The standalone SKILL.md also works when placed in a folder with the same skill name. Check your tool's current instructions: Codex documentation · Claude Code documentation.
What the score does not prove
No guaranteed score of 28, and no guarantee against account restrictions. This site's score is a reference metric, not a service provider's actual decision. Judge the measured settings and network results.
- A Fake-IP response alone does not prove there are no DNS leaks.
- TUN does not make a proxy undetectable. Resolver routing, bootstrap queries, IPv6 and exclusions still need verification.
- Inspect the source of managed Chrome policies; writing an ordinary preference does not prove a policy took effect.
Configuration references: Mihomo TUN · Mihomo DNS · Chrome privacy API. The skill lists the full sources. Checked: 2026-10-15.