Sentinel Network

A multi-tenant blockchain monitoring system for DAOs to track on-chain activity securely and in isolation.

What It Does

Sentinel Network monitors Ethereum blockchain addresses and streams events to multiple tenants, each seeing only their own data. Built for Web3 infrastructure with cost-efficiency in mind.

Components

• Watcher Service: Polls Ethereum via Alchemy, detects transactions, stores events in SQLite
• Aggregator API: FastAPI service with tenant authentication - each tenant queries only their data
• Blockchain Proxy: RPC request caching layer (memory/Redis backends)
• IPFS Integration: Archives significant events to distributed storage

What's Implemented

✅ Core Architecture

• Tenant isolation via API keys (X-Tenant-Key header)
• SQLite database with per-tenant tables
• Alchemy RPC integration (Sepolia testnet)
• Blockchain polling with catch-up logic

✅ API Features

• /health - Service health check
• /api/v1/events - Get tenant events with pagination
• /api/v1/events/{tx_hash} - Event details
• /api/v1/addresses - Add addresses to watch
• Comprehensive error handling & logging

✅ Infrastructure

• In-memory caching (5min TTL) - Redis ready for prod
• Multi-tenant request logging
• Configuration via YAML + environment variables
• Systemd-ready services

Quick Start

# Install dependencies
pip install -r watcher-service/requirements.txt
pip install -r aggregator/requirements.txt

# Set up environment
cp aggregator/.env.example aggregator/.env
cp watcher-service/.env.example watcher-service/.env

# Start services
python3 watcher-service/watcher.py &
uvicorn aggregator.main:app --port 8006

# Test API
curl -H "X-Tenant-Key: alpha-secret-key-123" http://localhost:8006/api/v1/events

Configuration

Tenants (watcher-service/config/tenants.yaml)

tenants:
  dao-alpha:
    api_key: alpha-secret-key-123
    watch_addresses: [0x...]
    alert_threshold_eth: 10.0

Environment Variables

• ALCHEMY_API_KEY - RPC endpoint key
• IPFS_API_URL - IPFS node endpoint
• SENTINEL_DB_PATH - Database location
• LOG_LEVEL - Logging verbosity

Testing

# Health check (no auth required)
curl http://localhost:8006/health

# Query with tenant key
curl -H "X-Tenant-Key: alpha-secret-key-123" \
  http://localhost:8006/api/v1/events

# Test auth failure
curl -H "X-Tenant-Key: invalid" \
  http://localhost:8006/api/v1/events  # Returns 401

Architecture

Ethereum → Alchemy RPC → Watcher → SQLite DB → Aggregator API → Tenant
                           ↓
                         IPFS (significant events)

Git Workflow

• main - Protected branch (production ready)
• Feature branches: feature/watcher-ipfs-integration
• Conventional commits: feat:, fix:, docs:

Next Steps

• Deploy to AWS (VPC, EC2, RDS)
• Redis for production caching
• NGINX gateway with subdomain routing
• CloudWatch monitoring & alarms
• Multi-chain support