Chrome DevTools getting in your way? Try Harness-FE

English translation in progress.

The full essay is available in Simplified Chinese:

→ Chrome DevTools 不好用?不妨试试 Harness-FE

Until the English version lands, here's the 30-second pitch:

QA pings you: "this button doesn't work." You try it yourself — works fine. By the time you ask for details, the first scene is gone. Multi-account testing across Chrome profiles? Mobile debugging? Same problem — there's no stable, structured record of what just happened that the agent can pick up.

Chrome DevTools MCP exists but only sees the tab in front of you. The tabs that matter — QA's tab, the mobile tab, the past tab — are invisible to it.

Harness-FE installs a runtime in every browser the dev cluster touches and keeps a structured session timeline in a local daemon. Every storage write, every fetch, every navigation carries the JS stack that issued it. The agent reads the timeline, jumps to the source line via the JSX data-morphix-loc tag, proposes a fix, then drives the browser back to verify.

The full Chinese version walks through a real "user keeps getting logged out" debug session resolved in 90 seconds, plus the architecture, four more case studies, why I built this, and what's next.

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Try it

npx @harness-fe/skill install

Then ask your agent: "Set up Harness-FE in this project."

• Docs (EN + 简体中文)
• GitHub (MIT)
• MCP tools reference