DEMO / RECORDING
Overview & result
Sarah Drasner shared a Chrome extension whose side panel discovers a page’s WebMCP tools. As the user types, Jev predicts a relevant tool, fills supported arguments and shows confidence and latency. The repository includes a grocery-shopping demo and describes confirmation for state-changing actions.
From the original post
🎇 I made a small Chrome extension: a side panel that drives any site's WebMCP tools with Jev!
When you type, on every keystroke it picks the relevant page's tool, fills in the arguments, and tells you how sure it is.
Here it is grocery shopping:
How Jev fits in the loop
- Discover the active page’s WebMCP tool schemas.
- Convert tool and argument choices into Jev typed questions.
- Show the predicted call and confidence in the side panel; require user confirmation for consequential actions.
How to reproduce
- Use Chrome 149 or newer with WebMCP available.
- Load https://github.com/sdras/jev-webmcp-extension as an unpacked extension; the README says there is no build step.
- Add a TypeSafe API key in the extension settings and enable access for a WebMCP-enabled site.
Why this build matters
The demo shows Jev selecting page-provided tools while the user types, with confidence and arguments visible before execution.
Limitations
- Requires Chrome 149 or newer and a page exposing WebMCP tools.
- The extension requests site access individually and confirms state-changing calls.