Bolt
security
Environment Variables Exposed in Bolt Client Bundle
Your Bolt.new application is bundling sensitive environment variables into the client-side JavaScript code. Anyone who opens browser DevTools can see your API keys, database connection strings, Stripe secret keys, or other credentials that should never leave the server.
This happens because Bolt's AI may prefix environment variables with VITE_ or NEXT_PUBLIC_, which tells the bundler to include them in the frontend build. While this is correct for public configuration like your site URL, it exposes any secret placed behind those prefixes.
The exposure is often discovered when you receive a massive bill from a third-party API, notice unauthorized data in your database, or when a user reports finding credentials in your page source. By then, the damage may already be done.
Error Messages You Might See
Unauthorized: Invalid API key detected from client IP
403 Forbidden - API key restricted to server-side use only
Billing alert: Unusual API usage spike detected
Warning: Secret key should not be used in client-side code
Common Causes
- VITE_ prefix on secret keys — Bolt generated environment variables like VITE_STRIPE_SECRET_KEY or VITE_DATABASE_URL, causing Vite to bundle them into client JavaScript
- Hardcoded secrets in source files — API keys placed directly in .ts or .tsx files rather than using environment variables at all
- No backend proxy for API calls — The app calls third-party APIs (OpenAI, Stripe, Twilio) directly from the browser with embedded keys
- All env vars loaded client-side — A shared config file imports every environment variable and is used in both server and client code
- .env file committed to Git — The .env file containing all secrets was committed to the repository and is visible in the build output
How to Fix It
- Audit your bundle for secrets — Open browser DevTools, go to Sources, and search for 'key', 'secret', 'password', 'token', 'DATABASE' in your JavaScript bundles
- Remove VITE_ prefix from secrets — Rename VITE_STRIPE_SECRET_KEY to STRIPE_SECRET_KEY so it is only available server-side
- Create server-side API routes — Move all third-party API calls to backend routes or Supabase Edge Functions where secrets stay on the server
- Rotate all compromised credentials — If secrets were exposed in production, immediately generate new keys in each provider's dashboard and revoke the old ones
- Separate public and private config — Create two config files: one for public values (VITE_ prefixed) and one for server-only values (no prefix)
- Add .env to .gitignore — Ensure your .env file is listed in .gitignore and remove it from Git history with git filter-branch or BFG Repo Cleaner
Real developers can help you.
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.
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.
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
Luca Liberati
I work on monoliths and microservices, backends and frontends, manage K8s clusters and love to design apps architecture
Caio Rodrigues
I'm a full-stack developer focused on building practical and scalable web applications. My main experience is with **React, TypeScript, and modern frontend architectures**, where I prioritize clean code, component reusability, and maintainable project structures.
I have strong experience working with **dynamic forms, state management (Redux / React Hook Form), and complex data-driven interfaces**. I enjoy solving real-world problems by turning ideas into reliable software that companies can actually use in their daily operations.
Beyond coding, I care about **software quality and architecture**, following best practices for componentization, code organization, and performance optimization.
I'm also comfortable working across the stack when needed, integrating APIs, handling business logic, and helping transform prototypes into production-ready systems.
My goal is always to deliver solutions that are **simple, efficient, and genuinely useful for the people using them.**
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:
💡 Developing cross-platform apps using Flutter, Dart, and Jetpack Compose for Android, iOS, and Web.
🖋️ Sharing insights through technical writing, blogging, and open-source contributions.
🤝 Collaborating closely with designers, PMs, and developers to build seamless mobile experiences.
Notable Achievements:
🎯 Revamped the Vepaar app into Vepaar Store & CRM with a 2x performance boost and smoother UX.
🚀 Launched Compose101 — a Jetpack Compose starter kit to speed up Android development.
🌟 Open source contributions on Github & StackOverflow for Flutter & Dart
🎖️ 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.
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.
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
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.
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)
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
Which environment variables are safe to expose in the browser?
Only values that are truly public: your Supabase anon key (with proper RLS), site URL, Google Analytics ID, and public feature flags. Never expose database URLs, secret API keys, or payment processor secret keys.
How do I check if my keys have already been exploited?
Check the usage dashboard for each exposed service. Look for API calls you didn't make, unexpected charges, or unfamiliar data in your database. Also check if your .env file appears in any public Git commits.