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.

Anthony Akpan Anthony Akpan Developer with 8 years of experience building softwares fro startups AUXLE AUXLE I am a Full Stack Developer experienced in building Websites, Web apps and Cross Platform Mobile Apps for Startups and Companies. Jaime Orts-Caroff Jaime Orts-Caroff I'm a Senior Android developer, open to work in various fields 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. BurnHavoc BurnHavoc Been around fixing other peoples code for 20 years. Richard McSorley Richard McSorley Full-Stack Software Engineer with 8+ years building high-performance applications for enterprise clients. Shipped production systems at Walmart (4,000+ stores), Cigna (20M+ users), and Arkansas Blue Cross. 5 patents in retail/supply chain tech. Currently focused on AI integrations, automation tools, and TypeScript-first architectures. Krishna Sai Kuncha Krishna Sai Kuncha Experienced Professional Full stack Developer with 8+ years of experience across react, python, js, ts, golang and react-native. Developed inhouse websearch tooling for AI before websearch was solved : ) Milan Surelia Milan Surelia Milan Surelia is a Mobile App Developer with 5+ years of experience crafting scalable, cross-platform apps at 7Span and Meticha. At 7Span, he engineers feature-rich Flutter apps with smooth performance and modern UI. As the Co-Founder of Meticha, he builds open-source tools and developer-focused products that solve real-world problems. Expertise: šŸ’” Developing cross-platform apps using Flutter, Dart, and Jetpack Compose for Android, iOS, and Web. šŸ–‹ļø Sharing insights through technical writing, blogging, and open-source contributions. šŸ¤ Collaborating closely with designers, PMs, and developers to build seamless mobile experiences. Notable Achievements: šŸŽÆ Revamped the Vepaar app into Vepaar Store & CRM with a 2x performance boost and smoother UX. šŸš€ Launched Compose101 — a Jetpack Compose starter kit to speed up Android development. 🌟 Open source contributions on Github & StackOverflow for Flutter & Dart šŸŽ–ļø Worked on improving app performance and user experience with smart solutions. Milan is always happy to connect, work on new ideas, and explore the latest in technology. Yovel Cohen Yovel Cohen I got a lot of experience in building Long-horizon AI Agents in production, Backend apps that scale to millions of users and frontend knowledge as well. 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

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