Building Secure Forms: Supabase RLS + Cloudflare Turnstile Guide
Anonymous forms (like "Contact Us" or "Get a Quote") are essential for gathering leads, but they open your database up to spam bots and malicious attacks if not properly secured.
In this video, I show you exactly how a simple form can be exploited using browser developer tools to flood a database—and then I show you how to lock it down completely. We’ll be using Bolt.new, Supabase, and Cloudflare Turnstile to create a secure, bot-proof submission flow.
I decided to keep the real-time debugging and struggles in this edit. You’ll see me run into issues with secrets and configuration, and watch how we troubleshoot them live.
In this video, we cover:
⚠️ The Risks: Why anonymous forms are vulnerable to DB flooding and deletion.
🕵️ The Hack: How to use Browser Dev Tools (F12) to bypass frontend validation and spam a database.
🔒 Row Level Security (RLS): How to use Supabase RLS to stop unauthorized writes.
🤖 Cloudflare Turnstile: Implementing a free, invisible CAPTCHA to verify human users.
☁️ Edge Functions: Moving form logic from the frontend to a secure backend function.
🛠️ Real-time Debugging: Troubleshooting API keys and secrets in Bolt.
Tools used:
Bolt.new (AI Web Builder)
Supabase (Backend & Database)
Cloudflare Turnstile (Bot Protection)
If you are a "vibe coder" building apps with AI, understanding how data flows from your frontend to your backend is a critical skill to keep your apps safe.
Slides:
https://docs.google.com/presentation/...
Prompts:
"Enable Row Level Security on the form table in the database so that anonymous users cannot read, write, or delete any data."
"Add a Cloudflare Turnstile widget to the form, ensuring the submit button is disabled until verified. Then, create a Supabase Edge Function that validates the token and inserts the form data into the database."
Connect with me: Twitter/X: @tristanbob
#Supabase #Cloudflare #WebSecurity #BoltNew #VibeCoding #WebDev #Tutorial