Jev × WebMCP
Turn WebMCP schemas and user wording into inspectable browser tool calls with typed Jev decisions.
What Jev decides
Which tool fits, which allowed value each typed parameter should take, and whether optional values were actually stated.
The Chrome side panel discovers tools exposed by the current page, converts their schemas into Jev questions, predicts a tool and arguments while the user types, and keeps consequential calls behind confirmation.
- Jev role
- Select one page-exposed WebMCP tool and populate only arguments that can be derived from its schema and the user input.
- Input
- The user request plus discovered tool names, descriptions, parameter schemas, enums, annotations, and values parsed from the request.
- Output
- Choice and Noul answers that form a schema-valid candidate tool call.
- Decision frequency
- Recomputed while the user types or manually selects a candidate tool.
- Fallback
- Leave unresolved fields blank, return no matching tool, require confirmation for writes, and never invent a free-text parameter outside user-provided spans.
How it works
Overview
Jev × WebMCP is a Chrome extension for pages that expose WebMCP tools. It converts the discovered tool list and parameter schemas into bounded questions: Choice for tools, enums, ranges and user-text spans; Noul for booleans and optional-field presence; and typed handling for arrays and stated numbers. Predictions, alternatives, confidence and latency remain visible in the side panel.
Read-only tools may run automatically when confidence is sufficient. State-changing tools require Enter, and consequential annotations such as checkout require a second confirmation regardless of confidence. Missing arguments remain blank for manual input, unmatched requests select no tool, and the extension grants host access one site at a time.
- Language
- JavaScript
- License
- Apache-2.0
- Author
- Sarah Drasner
Sources
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