After building a fitness tracker as a side project, I realized the backend plumbing (auth, cloud sync, AI proxy with quota, RLS) was ~4 weeks of work that most React Native templates skip entirely. So I rebranded mine as Reptron and shipped it as a template. Live: https://8628671192007.gumroad.com/l/mbmmh The architecture mermaid flowchart LR App[📱 React Native App] -->|JWT| Worker[⚡ Cloudflare Worker<br/>auth + quota] App -->|JWT| Supabase[☁️ Supabase<br/>Postgres + RLS] Worker -->|server secret| Groq[🤖 Groq Llama 3.1] \`\`\` (The Groq API key never ships in the app bundle — it lives as a Cloudflare secret on the Worker.) ## What's actually in it ### Production backend (the actual value) - **Cloudflare Worker proxy** that hides the Groq API key — verifies Supabase JWT via cached JWKS (1h TTL), enforces 50 req/user/day quota in KV (26h TTL covers the UTC day boundary) - **Supabase Postgres with RLS** — users only see their own data, verified at the database level - **Idempotent cloud…