TL;DR
Bolt.new can build functional apps quickly, but the generated code often lacks production-ready security. Common issues include missing authentication, exposed API keys in frontend code, and absent input validation. The platform itself is safe, but you should never ship a Bolt app to production without a security review. Export your code and fix security issues before going live.
What is Bolt.new?
Bolt.new is an AI-powered app builder that generates full-stack applications from natural language prompts. You describe what you want, and Bolt creates a working app with frontend, backend, and database components.
Bolt is built by StackBlitz and runs entirely in your browser using WebContainers technology. The apps it creates can be deployed to various platforms or exported for further development.
Our Verdict
What's Good
- Browser-based, nothing installed
- Modern frameworks (React, Next.js)
- Integrates with Supabase
- Code is exportable
- Great for prototypes
What to Watch
- Auth often missing or incomplete
- API keys can leak to frontend
- No input validation by default
- Database rules need setup
- Not production-ready as-is
Security Issues We Commonly Find
1. Missing or Broken Authentication
Bolt often creates apps without proper authentication, or with auth that only works on the frontend. This means:
- API endpoints can be called by anyone
- User data isn't properly protected
- Admin features may be accessible without login
Real example: We scanned a Bolt-generated SaaS app where the "delete user" API endpoint had no authentication. Anyone with the URL could delete any user account.
2. Exposed API Keys
Bolt sometimes puts API keys directly in frontend code, which means anyone can see them by viewing the page source. This is especially problematic for:
- OpenAI API keys (can result in huge bills)
- Stripe secret keys (payment fraud risk)
- Database credentials (full data access)
3. Missing Database Security
When Bolt connects to Supabase or Firebase, it often doesn't set up Row Level Security (RLS) or security rules. This means:
- Anyone with the database URL can read all data
- Users can access other users' data
- Data can be modified or deleted by anyone
4. No Input Validation
Bolt-generated forms typically don't validate or sanitize user input, creating risks for:
- SQL injection attacks
- Cross-site scripting (XSS)
- Data corruption from malformed input
Security Comparison
| Security Feature | Bolt Default | Production Ready |
|---|---|---|
| Authentication | Often missing | Required for user data |
| API key handling | May be in frontend | Environment variables only |
| Database security | RLS not configured | RLS policies required |
| Input validation | Usually missing | Server-side validation |
| HTTPS | Yes (on deploy) | Yes |
| Rate limiting | Not included | Required for APIs |
How to Ship Bolt Apps Safely
1. Export and Review the Code
Don't deploy directly from Bolt. Export your code and review it for security issues before going to production.
2. Add Proper Authentication
Implement server-side authentication on all protected endpoints. Consider using Clerk, Auth0, or Supabase Auth with proper configuration.
3. Move Secrets to Environment Variables
Search your code for any API keys or credentials. Move them to server-side environment variables and access them only from backend code.
4. Configure Database Security
If using Supabase, enable Row Level Security on all tables and write appropriate policies. If using Firebase, set up security rules.
5. Add Input Validation
Implement server-side validation for all user input using libraries like Zod or Yup. Never trust client-side validation alone.
Tip: Use the prompt "Review this code for security vulnerabilities" to ask Bolt to identify potential issues. It won't catch everything, but it helps.
Is Bolt Safe for Prototypes?
Yes, Bolt is excellent for prototypes and demos where security isn't critical. Use it for:
- MVP testing with fake data
- Proof of concept demos
- Internal tools (if your network is secure)
- Learning and experimentation
Important: Even for prototypes, avoid using real API keys or connecting to production databases. Create separate test accounts and databases.
Bolt vs Similar Platforms
| Feature | Bolt.new | Lovable | v0 |
|---|---|---|---|
| Full-stack apps | Yes | Yes | Frontend only |
| Auth built-in | Partial | Partial | No |
| Database integration | Supabase | Supabase | No |
| Security defaults | Minimal | Minimal | N/A (UI only) |
| Code exportable | Yes | Yes | Yes |
Can I use Bolt.new for a production app?
You can, but you shouldn't deploy Bolt-generated code directly to production without a thorough security review. Export the code, fix security issues (especially authentication and API key handling), and then deploy. The code quality is a good starting point but needs hardening.
Is my code private in Bolt.new?
Projects in Bolt are private to your account. However, the AI processes your code to generate responses. Review StackBlitz's privacy policy for details on data handling. For highly sensitive projects, consider exporting and working locally.
Why does Bolt create insecure code?
Bolt optimizes for getting apps working quickly, not for security. AI models are trained on code that often lacks security best practices. The tool assumes you'll add security measures before production deployment.
How do I add authentication to a Bolt app?
Export your code and integrate an authentication provider like Clerk, Auth0, or Supabase Auth. Make sure to add authentication checks to both your frontend routes and backend API endpoints. Frontend-only auth is not sufficient.
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