How I Would Fix exposed API keys and missing auth in a React Native and Expo founder landing page Using Launch Ready.

How I Would Fix exposed API keys and missing auth in a React Native and Expo founder landing page Using Launch Ready

The symptom is usually simple to spot: the app works, but sensitive API keys are sitting in the client bundle, the landing page or mobile flow has no real auth gate, and anyone who opens DevTools or inspects network traffic can see more than they should. In practice, that means leaked third-party credentials, broken trust, possible billing abuse, and a support mess before you even launch.

The most likely root cause is that the founder used Expo and React Native to move fast, then pushed secrets into the frontend because it was the quickest path to "working." The first thing I would inspect is the production build output and environment handling: what is bundled into the app, what is fetched from secure backend endpoints, and whether any route or screen assumes a user is authenticated when it should not.

Triage in the First Hour

1. Check the live app bundle for hardcoded keys.

• Search for `sk_`, `pk_`, `apiKey`, `secret`, `token`, and vendor names in source and built artifacts.
• Inspect JS bundles from Expo web or OTA updates if they are public.

2. Review deployment logs and release history.

• Confirm when secrets were introduced.
• Identify whether a recent build or config change exposed them.

3. Audit all connected accounts.

• Cloud provider, email provider, analytics, payment processor, database, CRM, and any AI API account.
• Rotate anything that was exposed publicly.

4. Inspect auth flow screens.

• Verify whether anonymous users can reach internal pages, admin actions, or protected APIs.
• Check if "login" is only visual and not enforced server-side.

5. Review environment variable usage.

• Separate build-time variables from runtime secrets.
• Confirm nothing sensitive is stored in `app.config.js`, `.env`, or public config objects.

6. Check API gateway, backend logs, and rate limits.

• Look for unusual request volume or repeated calls from unknown IPs.
• Confirm rate limiting exists on public endpoints.

7. Verify domain and hosting controls.

• Check DNS records, Cloudflare settings, SSL status, redirects, and subdomains.
• Make sure production traffic cannot bypass protection layers.

8. Capture current state before changing anything.

• Save screenshots of auth screens.
• Export current config values safely.
• Record active versions so rollback is possible.

A quick diagnostic command I would run early:

grep -RInE "sk_|pk_|apiKey|secret|token|Bearer|Authorization" .

This does not fix anything by itself. It tells me where the risk lives so I can remove it without breaking the product.

Root Causes

1. Secrets were placed in client-side code.

• Common in Expo because everything feels like "app code."
• Confirm by checking built JS bundles and config files for live credentials.

2. The app uses public keys where private keys were required.

• Some vendors provide publishable keys for frontend use and secret keys for server use.
• Confirm by comparing each key against vendor docs and its intended permission scope.

3. Auth exists only in UI state.

• The screen hides content after a button tap, but APIs do not enforce access control.
• Confirm by calling protected endpoints directly with no session or invalid session.

4. Environment variables are misclassified.

• A variable may be prefixed or injected into Expo in a way that makes it public at build time.
• Confirm by checking `app.config.js`, EAS config, CI variables, and any `EXPO_PUBLIC_` usage.

5. Third-party scripts or SDKs are initialized too early.

• Analytics, chat widgets, payment SDKs, or AI tools may run before auth checks complete.
• Confirm by reviewing network calls on first load with a fresh browser profile.

6. No backend boundary exists yet.

• The founder tried to build a landing page that also acts like an app without adding a server layer for secret handling and authorization checks.
• Confirm by looking for direct client-to-vendor calls that should be proxied through a backend function.

The Fix Plan

My approach is to stop exposure first, then rebuild the boundary between public UI and private operations. I would not keep patching around leaked secrets while leaving the same architecture in place.

1. Rotate every exposed secret immediately.

• Revoke old keys before shipping code changes if exposure is confirmed.
• This includes API providers, email services, analytics admin tokens, database credentials, webhook secrets, and any service account keys.

2. Remove all private secrets from the client app.

• Keep only truly public identifiers in Expo if the vendor allows it.
• Move secret-dependent operations behind serverless functions or a small backend API.

3. Add real authorization checks on every protected action.

• Do not trust hidden screens or disabled buttons as security controls.
• Enforce access control on the server side using session validation or signed tokens.

4. Split public landing content from authenticated product logic.

• The marketing page should remain public and fast to load.
• Any lead capture enrichment, billing action, user data access, or admin workflow should require authenticated backend access.

5. Use secure runtime storage for tokens on device only when needed.

• Store short-lived session tokens securely with platform-safe storage options.
• Never store long-lived secrets in local storage or plain text config files.

6. Lock down CORS, origin rules, and rate limits on APIs.

• Allow only expected origins during production rollout.
• Rate-limit signup forms, passwordless login endpoints, contact forms with automation hooks, and any endpoint that can be abused for spam or billing fraud.

7. Harden deployment configuration through Launch Ready standards.

• Set up DNS correctly with Cloudflare proxying where appropriate.
• Enable SSL everywhere, redirect HTTP to HTTPS, enforce canonical domains/subdomains,

configure SPF/DKIM/DMARC for outbound email, add caching rules where safe, enable DDoS protection, set environment variables correctly, verify uptime monitoring, and document rollback steps before handover.

8. Add server-side logging without leaking secrets into logs.

• Log auth failures as events without printing tokens or headers verbatim.
• Track request IDs so you can trace issues without exposing customer data.

9. Ship one safe fix at a time with rollback ready.

• First remove exposure and rotate credentials.

Then add auth enforcement. Then validate redirects and monitoring after deployment.

A simple decision path I would follow:

Regression Tests Before Redeploy

I would not redeploy until these checks pass in staging with production-like settings.

• Secrets scan passes
• No private key patterns appear in source control or built artifacts
• No secret values exist in client-accessible config

• Auth enforcement passes

- Unauthenticated users cannot reach protected screens - Protected API routes return 401 or 403 when expected

• Session behavior passes

- Valid sessions survive refresh within policy - Expired sessions force re-authentication cleanly

• Public page behavior passes

- Landing page still loads without login - Lead capture forms still submit successfully

• Security headers and transport pass

- HTTPS enforced - No mixed content - CORS allows only approved origins

• Abuse checks pass

- Rate limits trigger on repeated failed requests - Webhook endpoints reject unsigned payloads

• Mobile UX checks pass

- Loading states appear while auth resolves - Error states explain what failed without exposing internals

Acceptance criteria I would use:

• Zero exposed private keys in repo history going forward from this sprint branch。
• All protected endpoints reject anonymous requests。
• Production deploy completes with no critical console errors。
• Uptime monitoring alerts within 5 minutes of endpoint failure。
• Support tickets related to login confusion drop below 2 per week after release。

Prevention

The best prevention is boring process that catches leaks before customers do. I would put guardrails at code review, CI/CD, deployment configuration, and product design level so this does not become a recurring fire drill.

• Code review guardrails

- Reject any PR that adds secret values to client code。 - Require reviewers to check auth boundaries before merge。

• CI security checks

- Run secret scanning on every push。 - Fail builds when sensitive patterns are detected。 - Add dependency audits for packages with known security issues。

• Deployment guardrails

- Keep production env vars out of source control。 - Use separate dev/staging/prod accounts。 - Rotate credentials on a schedule。

• UX guardrails

- Make protected areas visually distinct from public marketing pages。 - Show clear sign-in states instead of silent failures。 - Avoid fake "locked" buttons that imply security but do nothing。

• Performance guardrails

- Keep landing page scripts minimal so security checks do not slow first paint。 - Watch LCP under about 2.5 seconds on mobile。 - Keep CLS near zero by reserving layout space for auth banners and modals。

• Monitoring guardrails

- Alert on spikes in failed auth requests। - Track unexpected geographic traffic। - Monitor vendor API usage so leaked keys cannot silently burn budget।

If I were auditing this stack regularly, I would also test prompt injection paths if any AI features exist later, because founders often add chat helpers after launch without rechecking data boundaries or tool permissions.

When to Use Launch Ready

Launch Ready fits when the product works enough to show users but is not safe enough to ship publicly yet. If your React Native + Expo founder landing page has exposed API keys, missing auth, broken redirects, uncertain DNS/SSL setup, or no monitoring, I can turn that into a controlled launch sprint instead of a guessing game.

I would handle:

• DNS setup and cleanup
• Redirects and canonical domains
• Subdomains for app/admin/api separation
• Cloudflare proxying and DDoS protection
• SSL verification
• Caching rules where appropriate
• SPF/DKIM/DMARC email setup
• Production deployment fixes
• Environment variables and secret handling cleanup
• Uptime monitoring setup
• Handover checklist with next steps

What you should prepare before booking:

• Repo access plus deployment access
• Domain registrar access
• Cloudflare access if already connected
• List of vendors using API keys
• Current staging/prod URLs
• Any existing auth provider details
• A short note on which screens must stay public versus private

If you want me to move fast, send me the repo plus access list first so I can audit exposure before touching layout polish or new features. That order matters because fixing UI while secrets are still exposed just delays the real problem.

References

1. roadmap.sh cyber security best practices: https://roadmap.sh/cyber-security 2. roadmap.sh API security best practices: https://roadmap.sh/api-security-best-practices 3. roadmap.sh code review best practices: https://roadmap.sh/code-review-best-practices 4. Expo environment variables: https://docs.expo.dev/guides/environment-variables/ 5. OWASP Authentication Cheat Sheet: https://cheatsheetseries.owasp.org/cheatsheets/Authentication_Cheat_Sheet.html

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Take the next step

If this is a problem in your product right now, here is what to do next:

• [Use the free Cyprian tools](/tools) - estimate cost, score app risk, check launch readiness, or pick the right service sprint.

• [Book a discovery call](/contact) - I will tell you honestly whether you need a sprint or if you can DIY the next step.

*Written by Cyprian Tinashe Aarons - senior full-stack and AI engineer helping founders rescue, launch, automate, and scale AI-built products.*