WebMCP DevTools icon

WebMCP DevTools

by theone · Developer Tools
Manifest V3 Free
View in Chrome Web Store Data as of 15 Oct 2026

Inspect, test, and monitor WebMCP tools via document.modelContext (legacy navigator.modelContext supported).

Users
293
+60 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
1
0 in 30 days
Store rank
#54K
#46K among extensions
Version
2.2.0
updated 9 Sep 2026

Users

monthly, 6 months
0146293Apr 2026Aug 2026Oct 2026
Latest, 15 Oct 2026: 293 usersMove the mouse over the chart for any month

Ratings count

monthly, 6 months
001Apr 2026Aug 2026Oct 2026
Latest, 15 Oct 2026: 1 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About WebMCP DevTools

WebMCP DevTools — A developer tool for inspecting, testing, and monitoring WebMCP tools. WebMCP (Web Model Context Protocol) is a browser-native API that allows web pages to register tools for AI models via navigator.modelContext. WebMCP DevTools gives you a powerful side panel to work with these tools in real-time. FEATURES • Tool Detection — Automatically detects all WebMCP tools registered on the current page • Declarative WebMCP — Auto-detects declarative tool definitions • Cross-Tab Aggregation — Unified view of tools from all open tabs • Schema Visualization — View input schemas as collapsible tree structures with advanced schema support • Interactive Form Generation — Auto-generates forms from JSON Schema for easy tool execution • Tool Execution — Execute tools directly from the side panel with instant results • AI Assistant — Built-in chat panel with streaming output, Markdown rendering, and code highlighting • Performance Statistics — Track success rate, average/min/max execution duration • Execution History — Review recent executions with full input/output details • Event Timeline — Track tool registration and change events in real-time • Snapshots & Diff — Save tool definition snapshots and compare changes • Export — Export as JSON, Markdown, Postman Collection, or TypeScript code • i18n — English and Chinese with one-click toggle • Themes — System-aware dark/light theme with manual override GETTING STARTED Enable the WebMCP flag: chrome://flags/#enable-webmcp-testing Click the extension icon to open the side panel Navigate to a page with WebMCP tools Inspect, execute, and monitor tools from the panel v2.1.0 — Tool Generator, Page Content Reading & Site Profiles New features: - Tool Generator: scan pages to discover forms, buttons and links, then auto-generate and inject WebMCP tool definitions - Page Content: read page metadata, text, tables, forms, and links for AI context - Contextual Prompts: page-level prompt templates for smarter AI interaction - Site Profiles: save tool definitions per domain and auto-inject on page load - UI redesign: tab bar with icons and overflow dropdown for better usability

Growth

WindowUsersChangeRatingsRating
7 days+28+10.6%00.00
30 days+60+25.8%00.00
6 months+289+7225.0%+1+5.00

Version history

4 versions recorded
2.2.09 Sep 2026
2.1.028 Apr 2026
2.0.023 Apr 2026
1.0.07 Apr 2026

Details

Category
Developer Tools
First seen
7 Apr 2026
Size
54 KB
Languages
en-US
Pricing
Free
Privacy policy
github.com
Extension ID
cgfogfkcfjdgpekdndcihajfjkaekjcl

Permissions and risk

Moderate riskimpact 2, likelihood 2
Permissions
sidePanelactiveTabscriptingstoragealarms
Site access
<all_urls>
Can read and change data on every website you visit.

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