Bolt deployment

Environment Variables Not Loading - Undefined in Build

Environment variables are undefined in your deployed application even though they're set in the platform. API keys, database URLs, and other config values come back as undefined.

Variables work fine locally but disappear after deployment.

Error Messages You Might See

process.env.API_KEY is undefined Fetch failed - API_URL is null TypeError: Cannot read property 'split' of undefined
process.env.API_KEY is undefinedFetch failed - API_URL is nullTypeError: Cannot read property 'split' of undefined

Common Causes

  1. Using process.env.VAR instead of NEXT_PUBLIC_VAR for client-side access
  2. Environment variables set after build completes
  3. Wrong environment selected in deployment platform (staging vs production)
  4. Variable name mismatch between code and platform settings
  5. Quotes or special characters in env var value causing parsing issues

How to Fix It

For client-side vars: prefix with NEXT_PUBLIC_ (e.g., NEXT_PUBLIC_API_URL)

For server-side only: use plain process.env.PRIVATE_VAR (won't leak to browser)

Set env vars BEFORE triggering redeploy in your platform

Test locally: create .env.local with same vars and run npm run build

Real developers can help you.

Rudra Bhikadiya 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. Prakash Prajapati 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. Mehdi Ben Haddou Mehdi Ben Haddou - Founder of Chessigma (1M+ users) & many small projects - ex Founding Engineer @Uplane (YC F25) - ex Software Engineer @Amazon and @Booking.com Bastien Labelle Bastien Labelle Full stack dev w/ 20+ years of experience Victor Denisov Victor Denisov Developer Antriksh Narang Antriksh Narang 5 years+ Experienced Dev (Specially in Web Development), can help in python, javascript, react, next.js and full stack web dev technologies. Dor Yaloz Dor Yaloz SW engineer with 6+ years of experience, I worked with React/Node/Python did projects with React+Capacitor.js for ios Supabase expert Sage Fulcher 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) Omar Faruk 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 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.

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

Get Help

Frequently Asked Questions

What's the difference between .env and .env.local?

.env is version controlled, .env.local is git-ignored. Use .env.local for secrets locally

How do I set env vars in Vercel?

Settings > Environment Variables. Make sure you set them before deploying

Should secrets use NEXT_PUBLIC_?

NO! Use NEXT_PUBLIC_ only for public values. Secrets stay as plain process.env.VAR and are only available on server

Related Bolt Issues

Can't fix it yourself?
Real developers can help.

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

Get Help