Open Source Revenue Leakage Detector for Marketplaces Built with n8n

Hey everyone 👋 Just finished building a revenue leakage detector for marketplaces using n8n + Supabase. The problem: Marketplaces lose 5-15% of revenue to missing commissions, wrong rates, and expired discount codes. Most don't even know it's happening. What I built: • 5 n8n workflows (transaction monitoring, validation, daily reports) • Python logic for commission calculations • Supabase for data storage • Real-time Slack alerts Test results: Found $18K-47K in leakage across 3 marketplace scenarios in 30 days. Made it fully open source: 📰Learn how it works: https://open.substack.com/pub/chukwuaugustus/p/i-built-a-system-that-saves-marketplaces?r=5ggncn&utm_medium=ios 📦 GitHub: https://github.com/Etherlabs-dev/marketplace-leak-detector 📝 Technical breakdown: https://dev.to/etherlabsdev/i-built-a-revenue-leakage-detector-that-saves-marketplaces-up-to-50kyear-open-source-4cgo Cost to run: ~$50/month Time to implement: 2-4 hours Happy to answer questions if anyone wants to implement it 🙌