BWAV - Bulk WhatsApp Number Checker with MCP

Lightweight, privacy-first Chrome extension to validate single and bulk WhatsApp numbers, with an optional MCP bridge for AI agents.

BWAV checks whether phone numbers are registered on WhatsApp, one at a time or in bulk. It opens your own WhatsApp Web tab and reads the screen, the same way you would by hand. No third-party APIs, no servers, no accounts. Why use it - Single and bulk checks. Paste one number or a thousand. - Real results. It drives a real WhatsApp Web session, so results match what you would see yourself. - Privacy-first. Everything runs in your browser. Numbers only ever go to WhatsApp Web inside your own logged-in session. - Zero dependencies. Pure vanilla JavaScript. No build step, no bloat. - Smart import. Paste from Excel or CSV, messy or clean. Country codes are normalized for you. - Export. HTML or CSV reports of who is registered and who is not. - Dark mode. Light, dark, or system. AI agents welcome BWAV ships a built-in MCP bridge (localhost only, off by default). Enable it in Settings, copy the generated config into your AI agent (Claude, opencode, Cursor), and the agent can check numbers through your real WhatsApp Web session. The extension and the bridge share a single lock, so checks never overlap. How it works 1. You give it a number or a list. 2. It opens or reuses a WhatsApp Web tab and navigates to the number's chat URL. 3. A content script inspects the page: chat input means REGISTERED, invalid-number dialog means NOT_REGISTERED, QR/login screen means NOT_LOGGED_IN, timeout means UNKNOWN. 4. Results land in the popup, ready to export. Privacy No accounts. No analytics. No tracking. No servers. Numbers you check are stored locally in chrome.storage.local and sent only to WhatsApp Web in your own session. The MCP bridge listens on 127.0.0.1 only, guarded by a token you generate. Full policy: https://duckb1t.github.io/bulk-whatsapp-number-checker/privacy.html Requirements - You must be logged into WhatsApp Web in a Chrome tab for checks to work. - Not affiliated with WhatsApp or Meta.