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.
Bastien Labelle
Full stack dev w/ 20+ years of experience
ISHANTDEEP SINGH
Senior Software Engineer with 7+ years of experience in React, JavaScript, TypeScript, Next.js, and Node.js. I’ve also worked as a tech lead for startups, owning end-to-end technical execution including architecture, development, scaling, and delivery. I bring a strong mix of hands-on coding, product thinking, and technical leadership, and I’m comfortable building products from scratch as well as improving and scaling existing systems.
AUXLE
I am a Full Stack Developer experienced in building Websites, Web apps and Cross Platform Mobile Apps for Startups and Companies.
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.**
Mehdi Ben Haddou
- Founder of Chessigma (1M+ users) & many small projects
- ex Founding Engineer @Uplane (YC F25)
- ex Software Engineer @Amazon and @Booking.com
rayush33
JavaScript (React.js, React Native, Node.js) Developer with demonstrated industry experience of 4+ years, actively looking for opportunities to hone my skills as well as help small-scale business owners with solutions to technical problems
Pratik
SWE with 15+ years of experience building and maintaining web apps and extensive BE infrastructure
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.
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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.
Taufan
I’m a product-focused engineer and tech leader who builds scalable systems and turns ideas into production-ready platforms.
Over the past years, I’ve worked across startups and fast-moving teams, leading backend architecture, improving system reliability, and shipping products used by thousands of users. My strength is not just writing code — but connecting product vision, technical execution, and business impact.
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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.