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.
Bastien Labelle
Full stack dev w/ 20+ years of experience
zipking
I am a technologist and product builder dedicated to creating high-impact solutions at the intersection of AI and specialized markets. Currently, I am focused on PropScan (EstateGuard), an AI-driven SaaS platform tailored for the Japanese real estate industry, and exploring the potential of Archify.
As an INFJ-T, I approach development with a "systems-thinking" mindset—balancing technical precision with a deep understanding of user needs. I particularly enjoy the challenge of architecting Vertical AI SaaS and optimizing Small Language Models (SLMs) to solve specific, real-world business problems. Whether I'm in a CTO-level leadership role or hands-on with the code, I thrive on building tools that turn complex data into actionable value.
prajwalfullstack
Hi Im a full stack developer, a vibe coded MVP to Market ready product, I'm here to help
Simon A.
I'm a backend developer building APIs, emulators, and interactive game systems. Professionally, I've developed Java/Spring reporting solutions, managed relational and NoSQL databases, and implemented CI/CD workflows.
Anthony Akpan
Developer with 8 years of experience building softwares fro startups
Meïr Ankri
Full-stack developer specializing in React / Next.js / Node.js with 6+ years of experience. I've worked across various sectors including automotive (Reezocar/Société Générale), healthcare (Medical Link SaaS), and e-commerce (Glasman). I build web apps end-to-end, from architecture to production, with a focus on scalability, performance, and code quality. I also mentor junior developers and contribute to technical decisions and code reviews.
Sage Fulcher
Hey I'm Sage! Im a Boston area software engineer who grew up in South Florida. Ive worked at a ton of cool places like a telehealth kidney care startup that took part in a billion dollar merger (Cricket health/Interwell health), a boutique design agency where I got to work on a ton of exciting startups including a photography education app, a collegiate Esports league and more (Philosophie), a data analytics as a service startup in Cambridge (MA) as well as at Phillips and MIT Lincoln Lab where I designed and developed novel network security visualizations and analytics. I've been writing code and furiously devoted to using computers to make people’s lives easier for about 17 years. My degree is in making computers make pretty lights and sounds. Outside of work I love hip hop, the Celtics, professional wrestling, magic the gathering, photography, drumming, and guitars (both making and playing them)
Alvin Voo
I’ve watched the tech landscape evolve over the last decade—from the structured days of Java Server Pages to the current "wild west" of Agentic-driven development. While AI can "vibe" a frontend into existence, I specialize in the architecture that keeps it from collapsing.
My expertise lies in the critical backend infrastructure: the parts that must be fast, secure, and scalable. I thrive on high-pressure environments, such as when I had only three weeks to architect and launch an Ethereum redemption system with minimal prior crypto knowledge, turning it into a major revenue stream.
What I bring to your project:
Forensic Debugging: I don't just "patch" bugs; I use tools like Datadog and Explain Analyzers to map out bottlenecks and resolve root causes—like significantly reducing memory usage by optimizing complex DB joins.
Full-Stack Context: Deep experience in Node.js and React, ensuring backends play perfectly with mobile and web teams.
Sanity in the Age of AI: I bridge the gap between "best practices" and modern speed, ensuring your project isn't just built fast, but built to last.
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.
Jen Jacobsen
I’m a Full-Stack Developer with over 10 years of experience building modern web and mobile applications. I enjoy working across the full product lifecycle — turning ideas into real, well-built products that are intuitive for users and scalable for businesses.
I particularly enjoy building mobile apps, modern web platforms, and solving complex technical problems in a way that keeps systems clean, reliable, and easy to maintain.
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.