Ying-Kai-Liao/jev-browser

jev-browser

Browser automation where an LLM plans and Jev decides.

Unofficial project, not affiliated with TypeSafe. It calls the TypeSafe System One API with your own API key.

The calling LLM (Claude, via MCP) says what outcome it wants, one step at a time, and hands over any text to type. For each round of a step, code describes the page. Then one ~300 ms Typesafe System One request asks Jev several questions at once: which element, which action, which value, and is the step done / blocked / showing an error / about to do something irreversible. Playwright performs the action. The LLM never reads page snapshots unless it chooses to take over.

Claude ── browser_do("Log in", {email, password}) ──▶ jev-browser
                                                       │  loop until done / stuck / needs confirmation
                                                       │   1. settle   (network + DOM quiet)
                                                       │   2. describe (elements, labels, state, visible text, diff, counts)
                                                       │   3. Jev      (done? error? irreversible? tool? target? value?)
                                                       │   4. act      (Playwright)
Claude ◀── { status: "done", url, actions[], done_score } ─┘

https://github.com/user-attachments/assets/2e688df9-4985-4854-8ebe-ba97c9d13d68

With WebMCP, a page offers its own tools. Jev chooses between those and the page's buttons, and fills each argument by picking one of the caller's values (text: values.g1 → "milk"), never by writing text:

https://github.com/user-attachments/assets/fe309fb8-aada-4187-a91e-f18493a39526

Jev only answers with probability distributions: yes/no (noul), pick one option (choice) or a rating (score). It never writes text. So everything free-form comes from the caller as candidates, and code turns disagreemen