Site Sense

site-sense

Give your AI coding CLI eyes into web portals. No cloud. No storage. Read-only.

You're in a conversation with your AI assistant. It says "go to the Azure Portal and check the NSG rules." You alt-tab, navigate, screenshot, describe what you see, paste it back. You are the human middleware.

site-sense eliminates this. The AI calls an MCP tool → your browser extension captures the active tab → the AI sees what you see.

Quick Start

Option A: Install from Chrome Web Store (recommended)

1. Install site-sense from the Chrome Web Store
2. Clone the repo and run setup:

git clone https://github.com/NordmanLive/site-sense.git
cd site-sense
npm install && npm run build
npm run setup -- --browser chrome    # or edge

Option B: Load unpacked (development)

git clone https://github.com/NordmanLive/site-sense.git
cd site-sense
npm install && npm run build
npm run setup -- --browser chrome    # or edge

Then load the extension manually:

1. Open edge://extensions (or chrome://extensions)
2. Enable Developer mode
3. Click Load unpacked → select dist/extension/

Add to your CLI's MCP config:

{
  "mcpServers": {
    "site-sense": {
      "command": "node",
      "args": ["/path/to/site-sense/dist/bridge/src/index.js"]
    }
  }
}

Then ask your AI: "What's on my browser tab?"

First time → popup appears → click Allow → done. All subsequent captures are automatic until you close the terminal.

How It Works

CLI (Claude Code / Copilot CLI)
    ↕ stdin/stdout (MCP protocol)
MCP Server (TypeScript)
    ↕ Unix domain socket (no network)
Native Host (thin relay)
    ↕ Chrome native messaging (stdio)
Extension (TypeScript, Manifest V3)
    ↕ inject → content → background
Browser Tab → accessibility tree + screenshot

Two MCP tools:

Tool	What it does
site_sense_capture	Accessibility tree + screenshot of active tab
site_sense_status	Check connection and session approval

Permission Modes

Mode	What happens	Install warning
Default	Click extension icon per page to grant access	None
All-sites	Toggle in popup → captures work on any page	One-time prompt

All-sites permission is revoked when the CLI session ends.

Security

Principle	How
No network	Native messaging (stdio) — invisible to DLP
No storage	Memory only — gone when CLI disconnects
No write ops	Never clicks, types, or modifies pages
No broad perms	activeTab + scripting + nativeMessaging
No secrets captured	Skips form values, strips URL tokens
Session-scoped	Permission resets every CLI session

See SECURITY.md for threat model and DLP compliance.

Architecture

Three-layer extension pipeline:

Layer	Context	Role
Inject	Page (world: MAIN)	Walks DOM, builds compact accessibility tree
Content	Isolated	Relays capture via postMessage (origin-validated)
Background	Service worker	Native messaging, session state, screenshot

Tech Stack

Component	Technology
Extension	TypeScript + Vite
MCP Server	TypeScript + @modelcontextprotocol/sdk + zod
Tests	vitest — 10 tests, <1s
Bundle	9KB extension, 7 total deps

Troubleshooting

Symptom	Fix
connected: false	Extension not loaded, or ID mismatch. Check edge://extensions.
Cannot capture	Navigate to an http:// or https:// page.
Content script not responding	Click the extension icon on the page, or enable all-sites mode.
Extension icon grayed out	Reload the extension at edge://extensions.

Docs

Doc	Purpose
SECURITY.md	Threat model, DLP compliance

License

Apache-2.0