BrainPlus

Your AI-powered knowledge assistant - A privacy-first browser extension that captures and organizes your browsing history using ML embeddings for semantic search, local RAG, and Ask Me Anything capabilities.

🔐 Your data never leaves your device. All browsing history, page content, and ML embeddings stay 100% local in your browser.

🎬 Demo

🏗️ Architecture

This is a monorepo containing:

• /extension: Chromium MV3 extension (Vite + React + TypeScript)
• /backend: FastAPI backend (Python + PostgreSQL + ClickHouse)

🎯 Key Features

• 🔒 100% Local & Private: Your data never leaves your device - all processing happens in your browser
• 🤖 Ask Me Anything (AMA): Query your browsing history with natural language
• 🧠 Local RAG: Retrieval-Augmented Generation with passage-level semantic search
• 🔍 Semantic Search: Find pages by meaning, not just keywords
• 📱 Cross-Device Sync: Sync history between mobile and desktop with end-to-end encryption
• 💾 Local-First Storage: All browsing history stays on your device in IndexedDB
• 🎯 ML-Powered Embeddings: 512-dimensional vectors using Universal Sentence Encoder (runs locally)
• 🛡️ Privacy-First: Denylist protection for 75+ sensitive domains (banking, healthcare, email)
• 📝 Smart Chunking: Sentence-aware passage generation for long documents
• 🗑️ Quality Eviction: Intelligent storage management based on recency, intent, and access patterns

🚀 Quick Start

Extension Development

cd extension
npm install
npm run dev        # Development with hot reload
npm run build      # Production build

Cross-Device Sync (Optional)

1. Start Signaling Server:

cd signaling-server
npm install
npm start          # WebSocket server on ws://localhost:8080

2. Install Native Messaging Host (Desktop only):

cd native-host
npm install
node install-manifest.js YOUR_EXTENSION_ID
# Restart Chrome after installation

3. Usage:

• Desktop: Click extension → Sync → Generate QR Code
• Mobile: Click extension → Sync → Scan QR Code → Camera opens
• Both devices sync automatically with E2E encryption

Backend Development (Optional)

cd backend
docker-compose up -d  # Start PostgreSQL, ClickHouse, Redis
pip install -r requirements.txt
uvicorn app.main:app --reload

📚 Documentation

• DESIGN_DOC.md: Complete technical design and onboarding document
  • System architecture and component details
  • Feature implementations (Search, Task Continuation, Cross-Device Sync)
  • Testing strategies and troubleshooting guides
  • API specifications and privacy architecture

🔒 Privacy & Security

Your Data Never Leaves Your Device:

• ✅ 100% Local Storage: All browsing history, page content, and ML embeddings stay on your device in IndexedDB
• ✅ Zero Data Collection: We never see, store, or have access to your browsing data
• ✅ No Cloud Sync: Your personal knowledge base is yours alone
• ✅ Offline-First: Full functionality without internet connection (except optional deals feature)

Additional Privacy Protections:

• 🛡️ Smart Denylist: Automatically blocks scraping of 75+ sensitive domains (banking, healthcare, email, government)
• 🔐 Encrypted Storage: AES-GCM encryption for sensitive data
• 🎭 Differential Privacy: Optional aggregated signals (for deals) use Laplace noise and k-anonymity
• 🚫 No PII: Only anonymous IDs if you choose to use the optional deals feature

📦 Tech Stack

Extension

• Framework: React 18 + TypeScript
• Build: Vite 5 with MV3 plugin
• ML: TensorFlow.js + Universal Sentence Encoder
• Storage: IndexedDB (local page digests) + chrome.storage.local (preferences)
• Privacy: All data stored locally, differential privacy for signals

Backend (Optional)

• API: FastAPI with async/await
• Database: PostgreSQL (deals catalog, points, signals)
• Deals: Server-side attribution for affiliate tracking
• Points: Reward system for user engagement

🧪 Testing

Extension

cd extension
npm test           # Unit tests
npm run test:e2e   # Brave compatibility tests

Backend

cd backend
pytest             # Unit + integration tests
pytest --brave     # Brave-specific test suite

📋 Development Phases

• ✅ Phase 0: Dead Code Elimination & Foundation
• ✅ Phase 1: IndexedDB & ML Infrastructure
• ✅ Phase 2: On-Device Inference (TensorFlow.js + USE)
• ✅ Phase 3: Semantic Search Feature
• ✅ Phase 4: Task Continuation Feature
• ✅ Phase 5: Cross-Device Sync (QR pairing, E2E encryption)
• 🚧 Phase 6: Testing & QA
• ⏳ Phase 7: LLM Integration (WebLLM, Streaming)
• ⏳ Phase 8: Chrome Web Store Deployment

🎯 Critical Success Factors

• Local-first architecture (IndexedDB)
• Privacy-first denylist (75+ sensitive domains)
• Semantic search with hybrid ranking
• Passage-level chunking and retrieval
• AMA with extractive answers and citations
• Quality-aware storage eviction
• Cross-device sync with E2E encryption
• QR code pairing (< 30 seconds)
• Smart merge conflict resolution
• Vector compatibility validation
• WebLLM integration (Phase 7)
• Streaming token generation (Phase 7)

📄 License

GNU Affero General Public License v3.0 (AGPL-3.0)

This project is licensed under the AGPL-3.0 License - see the LICENSE file for details.

Key Points:

• ✅ Free to use, modify, and distribute
• ✅ Must disclose source code of modifications
• ✅ Network use is considered distribution (SaaS clause)
• ✅ Derivatives must also use AGPL-3.0
• ✅ Protects user freedom and privacy

🤝 Contributing

Contributions welcome! This is an open-source project focused on privacy-first knowledge management.