Jev Browser

Let Jev drive your browser. You name a site and a goal; Jev, TypeSafe's single-forward-pass decision model, clicks, types and selects its way there in a real Chrome window while you watch. A few hundred milliseconds per decision.

Source code: github.com/zurfyx/jev-browser-skill
Step through a real run (interactive explainer): jev-browser.vercel.app

What it does

• Searches websites: enters your search terms and opens the result that matches your goal.
• Fills forms: types the values you provide, picks dropdown options, ticks checkboxes and submits.
• Logs in safely: a --secret is typed only into password fields and is never sent to Jev or printed.
• Shows its work: every step prints the operation, the target, Jev's probability and its latency, then a JSON summary with the final URL, title and visible page text.
• Uses your browser or its own: drives your Chrome (tabs and logins included) when remote debugging is allowed, otherwise a reusable Jev window whose logins persist between runs.

How it works

1. Observe. A snapshot runs inside the page and returns a numbered table of the visible controls. Jev never sees the DOM.
2. Ask. One request asks Jev for the next operation (CLICK, TYPE, SELECT, ENTER, DONE, BLOCKED) and a target for every operation at once, so two dependent decisions cost one round trip.
3. Validate. The code reads only the target matching the chosen operation. Any answer outside the offered set throws before anything runs. Model output never becomes a selector or code.
4. Execute with real mouse and keyboard events, then observe again until Jev answers DONE or BLOCKED.

Measured speed

A step is 3 to 6k input tokens and output is free, so the whole Hacker News run costs less than a tenth of a cent.

Built to be read

A reference implementation: three short files, six operations, no dependencies (no npm install, no Playwright, no browser download). scripts/core.mjs holds the whole decision logic in about 250 lines, and the explainer site replays recorded traces step by step, or runs the loop live with your key. Full docs are in the GitHub README.

Requirements

• Node 22+
• Chrome, Edge, Brave, Arc or Chromium
• A TypeSafe API key in TYPESAFE_API_KEY (environment or a .env file in the skill folder)

Known limitations

• Jev chooses, it never generates: every string to type must be supplied up front.
• At most 250 controls per page are offered (Jev takes up to 255 choices per question). For dense pages, start from a URL closer to the target.

MIT licensed. The action-space design follows browser-use/jev-ultrafast.