Common Issues
general
API Calls Failing With Errors in My AI App
Your app makes calls to an API (its own backend, Supabase, or a third-party service) and those calls fail. You see errors in the console like 500, 403, 404, or CORS errors.
Error Messages You Might See
CORS policy: No 'Access-Control-Allow-Origin' header
500 Internal Server Error
403 Forbidden
401 Unauthorized
net::ERR_CONNECTION_REFUSED
Timeout: request took too long
Common Causes
- CORS not configured — browser blocks requests from your domain to the API
- API key or auth token expired, missing, or wrong
- API endpoint URL is wrong (still pointing to localhost or old URL)
- Rate limiting — too many requests in a short time
- Backend server error (500) due to unhandled exceptions
How to Fix It
- Open browser Network tab (F12 > Network) and find the failing request — check the status code and response body
- For CORS errors: configure your API server to allow requests from your frontend domain
- For 401/403: check that your API key or auth token is being sent correctly in the request headers
- For 500: check server logs for the actual error — the frontend error won't have details
- For timeouts: check if the API endpoint is accessible from your deployment environment
Real developers can help you.
David Olverson
Solo dev shipping production apps with AI-assisted development. I specialize in rescuing broken Lovable/Bolt/Cursor builds and taking them to production. 10+ apps shipped including SaaS CRMs, gaming platforms, real estate tools, and Discord bots. Stack: Next.js 16, TypeScript, Tailwind CSS, FastAPI, PostgreSQL, Prisma. I use Claude Code with 50+ custom skills for rapid delivery. Average turnaround: 2-4 weeks from broken prototype to production.
Nam Tran
10 years as fullstack developer
Bastien Labelle
Full stack dev w/ 20+ years of experience
Prakash Prajapati
I’m a Senior Python Developer specializing in building secure, scalable, and highly available systems. I work primarily with Python, Django, FastAPI, Docker, PostgreSQL, and modern AI tooling such as PydanticAI, focusing on clean architecture, strong design principles, and reliable DevOps practices. I enjoy solving complex engineering problems and designing systems that are maintainable, resilient, and built to scale.
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.
Jaime Orts-Caroff
I'm a Senior Android developer, open to work in various fields
Luca Liberati
I work on monoliths and microservices, backends and frontends, manage K8s clusters and love to design apps architecture
Rudra Bhikadiya
I build and fix web apps across Next.js, Node.js, and DBs.
Comfortable jumping into messy code, broken APIs, and mysterious bugs.
If your project works in theory but not in reality, I help close that gap.
Basel Issmail
’m a Senior Full-Stack Developer and Tech Lead with experience designing and building scalable web platforms. I work across the full development lifecycle, from translating business requirements into technical architecture to delivering reliable production systems.
My work focuses on modern web technologies, including TypeScript, Angular, Node.js, and cloud-based architectures. I enjoy solving complex technical problems and helping teams turn product ideas and prototypes into working platforms that can grow and scale.
In addition to development, I often collaborate closely with product managers, business analysts, designers, and QA teams to ensure that solutions align with both technical and business goals.
I enjoy working with startups and product teams where I can contribute both as a hands-on engineer and as a technical partner in designing and delivering impactful software.
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
Describe what's wrong in plain English. No technical knowledge needed.
Get HelpFrequently Asked Questions
What does a CORS error mean?
CORS (Cross-Origin Resource Sharing) is a browser security feature. It means your frontend (e.g., on Vercel) is trying to call an API on a different domain, and that API hasn't been configured to allow it.
I get a 500 error but don't know what's wrong. How do I find out?
A 500 error means the server crashed. The actual error is in the server logs, not in the browser. Check your hosting platform's logs.