Lovable
security
CORS Misconfiguration in Lovable App
Your Lovable app either blocks legitimate requests with CORS errors or is configured with overly permissive CORS settings (Access-Control-Allow-Origin: *) that allow any website to make requests to your API.
CORS errors appear as failed API calls in the browser console, preventing your app from communicating with its backend or third-party services. On the other hand, wildcard CORS settings mean any malicious website could make requests to your API on behalf of your users.
This commonly happens when your frontend and backend are on different domains, or when Lovable generates API routes without proper CORS configuration.
Error Messages You Might See
Access to fetch at 'https://api...' has been blocked by CORS policy
No 'Access-Control-Allow-Origin' header is present on the requested resource
CORS policy: Response to preflight request doesn't pass access control check
The value of the 'Access-Control-Allow-Origin' header must not be the wildcard '*' when the request's credentials mode is 'include'
Common Causes
- Wildcard origin allowed — The API is configured with Access-Control-Allow-Origin: * which is insecure for authenticated endpoints
- Missing CORS headers — The backend doesn't include the necessary CORS headers, blocking frontend requests
- Credentials with wildcard — Trying to send cookies/auth headers with a wildcard CORS policy, which browsers block
- Preflight request failing — OPTIONS requests are not handled, causing complex requests (POST with JSON) to fail
- Different domains in production — Frontend and API are on different domains but CORS is only configured for localhost
How to Fix It
- Set specific allowed origins — Replace wildcard (*) with your actual frontend domain(s)
- Handle OPTIONS preflight — Make sure your server responds to OPTIONS requests with proper CORS headers
- Allow credentials properly — If using cookies/auth, set Access-Control-Allow-Credentials: true with a specific origin (not wildcard)
- Configure allowed methods and headers — Explicitly list the HTTP methods and headers your frontend needs
- Test with browser DevTools — Check the Network tab for failed preflight requests and missing headers
Real developers can help you.
hanson1014
Full-stack developer experienced in fixing and deploying AI-generated apps from Lovable, Bolt.new, Cursor, and Replit. I specialize in debugging Supabase integration issues (auth flows, RLS policies, database connections), fixing broken deployments, resolving routing/blank screen problems, and cleaning up messy React/Vite codebases. I also build production apps with the Claude API and have shipped a Mac desktop dev tool (Nexterm from scratch. Based in Hong Kong, fast turnaround.
Tejas Chokhawala
Full-stack engineer with 5 years experience building production web apps using React, Next.js and TypeScript.
Focused on performance, clean architecture and shipping fast.
Experienced with Supabase/Postgres backends, Stripe billing, and building AI-assisted developer tools.
Omar Faruk
As a Product Engineer at Klasio, I contributed to end-to-end product development, focusing on scalability, performance, and user experience.
My work spanned building and refining core features, developing dynamic website templates, integrating secure and reliable payment gateways, and optimizing the overall system architecture.
I played a key role in creating a scalable and maintainable platform to support educators and learners globally.
I'm enthusiastic about embracing new challenges and making meaningful contributions.
Antriksh Narang
5 years+ Experienced Dev (Specially in Web Development), can help in python, javascript, react, next.js and full stack web dev technologies.
Jared Hasson
Full time lead founding dev at a cyber security saas startup, with 10 yoe and a bachelor's in CS. Building & debugging software products is what I've spent my time on for forever
ISHANTDEEP SINGH
Senior Software Engineer with 7+ years of experience in React, JavaScript, TypeScript, Next.js, and Node.js. I’ve also worked as a tech lead for startups, owning end-to-end technical execution including architecture, development, scaling, and delivery. I bring a strong mix of hands-on coding, product thinking, and technical leadership, and I’m comfortable building products from scratch as well as improving and scaling existing systems.
Bastien Labelle
Full stack dev w/ 20+ years of experience
Matthew Jordan
I've been working at a large software company named Kainos for 2 years, and mainly specialise in Platform Engineering. I regularly enjoy working on software products outside of work, and I'm a huge fan of game development using Unity. I personally enjoy Python & C# in my spare time, but I also specialise in multiple different platform-related technologies from my day job.
Vlad Temian
15+ years shipping production infrastructure for startups. Former CTO at qed.builders (acquired by The Sandbox).
Cursor ambassador and agentic tooling builder.
I've scaled systems, automated deployments, and built observability tools for AI coding workflows. I specialize in taking vibe-coded apps from broken prototype to production-ready: fixing Supabase auth/RLS, Stripe integrations, deployment pipelines, and cleaning up AI-generated spaghetti.
I build tools in this space (agentprobe, claudebin, micode) and understand both sides: how AI generates code and why it breaks.
https://blog.vtemian.com/
Anthony Akpan
Developer with 8 years of experience building softwares fro startups
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
What is CORS and why does it exist?
CORS (Cross-Origin Resource Sharing) is a browser security feature that prevents websites from making requests to a different domain than the one that served the page. It protects users from malicious sites making unauthorized API calls.
Is it safe to use Access-Control-Allow-Origin: * ?
Only for public APIs that don't use authentication. For any API that handles user data or requires login, you must specify exact allowed origins.