Live demo · Jev × WebMCP

Jev picks the right tool, and gates the risky one

This page registers 13 real WebMCP tools (the browser standard where a site declares what an agent can do). Say what you want in plain words, and the same request goes to Jev and a normal LLM at once. Both pick a tool. Jev does it faster and hands back a calibrated confidence, so the one tool that acts in your name stops for approval on an honest number. The LLM gives a number too, but it isn't calibrated, so you can't safely gate on it.

Ask in plain words

The same request goes to Jev and a normal LLM at once. Both pick a tool; only one gives a gate you can trust. Try the last sample to see it.

What do you want to do?

Jev decision model

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confidence–

LLM gpt

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confidence–

Declared tools checking…

Registered on this page via document.modelContext. One is consequential.

Companion demo to the maze race and the writeup Jev: A Decision, Not a Paragraph. Tools are real WebMCP registrations; Jev runs live server-side. Enable chrome://flags/#enable-webmcp-testing to see them in DevTools.