site-sense

License: Apache-2.0

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

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

Load the extension in your browser:

Open edge://extensions (or chrome://extensions)
Enable Developer mode
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 — 11 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

site-sense

site-sense

Quick Start

How It Works

Permission Modes

Security

Architecture

Tech Stack

Troubleshooting

Docs

License

Resources

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