NewJev WebMCP Extension
A Chrome side panel that maps a user request to page-provided WebMCP tools and their typed arguments using Jev.
Added to Jevfast
NewHow it uses Jev
The extension converts discovered tool schemas and the current utterance into typed routing and parameter questions. Jev returns choices and Noul answers; local decoding constructs a proposed tool call for display or execution under confirmation rules.
What Jev decides
Basketful search example from the pinned tool fixtureExample answers · not a recorded Jev response · Source ↗
Question 1 · tool
YOUR APP
INSTRUCTION
Which action does the user request call for?
STATE
Representative pinned Basketful tool-schema fixture for the utterance “got anything gluten free in the bakery aisle?”. Shared state contains the user request and optional page site/title. Tool schemas generate the routing and parameter questions; other pages can offer different tools and values.
JEV · CHOICE
- choose_store
- search_products
- add_to_cart
- update_cart_item
- get_cart
- get_staples
- update_staples
- add_staples_to_cart
- add_recipe_to_cart
- start_checkout
- get_order_status
- set_delivery_options
- place_order
- __none__
Question 2 · search products::department
YOUR APP
INSTRUCTION
For the search_products action, which department does the request indicate?
STATE
Representative pinned Basketful tool-schema fixture for the utterance “got anything gluten free in the bakery aisle?”. Shared state contains the user request and optional page site/title. Tool schemas generate the routing and parameter questions; other pages can offer different tools and values.
JEV · CHOICE
- Produce
- Dairy & Eggs
- Bakery
- Meat & Seafood
- Pantry
- Frozen
- Beverages
- Snacks
- Household
Question 3 · search products::dietary::gluten-free
YOUR APP
INSTRUCTION
For search_products, does the request ask for the gluten-free dietary option?
STATE
Representative pinned Basketful tool-schema fixture for the utterance “got anything gluten free in the bakery aisle?”. Shared state contains the user request and optional page site/title. Tool schemas generate the routing and parameter questions; other pages can offer different tools and values.
JEV · NOUL
YesNo
App workflow
- Discover tools
The extension reads WebMCP tool definitions from the enabled page.
- Build request
It derives routing and parameter questions from tool schemas and the typed user request.
- Decode proposal
Local code combines Jev answers into a selected tool and arguments.
- Confirm and execute
The panel applies read-only and consequential-action confirmation rules before calling the page tool.
Why it is interesting
It compiles arbitrary page tool schemas into a consistent decision interface, including explicit handling for absent optional values and no matching tool.