How I Would Fix exposed API keys and missing auth in a Lovable plus Supabase AI-built SaaS app Using Launch Ready.

How I Would Fix exposed API keys and missing auth in a Lovable plus Supabase AI-built SaaS app Using Launch Ready

The symptom is usually obvious: someone finds your Supabase anon key, service role key, or a third-party API key in the frontend bundle, and users can hit protected data without logging in. In a Lovable-built SaaS app, the most likely root cause is that the prototype shipped with permissive rules, secrets were placed in client-side env vars, and auth checks were assumed instead of enforced.

The first thing I would inspect is the actual request path from browser to Supabase. I want to see which calls are public, which tables have Row Level Security disabled, and whether any sensitive logic is running in the client instead of an edge function or server route.

Triage in the First Hour

1. Check the live site source and browser network tab.

• Look for exposed keys in JS bundles, inline config, source maps, or network requests.
• Confirm whether any secret is visible in `window.__*`, public env vars, or fetched config.

2. Open Supabase dashboard and review project settings.

• Check Authentication status, providers, redirect URLs, JWT settings, and disabled features.
• Verify whether the service role key has ever been used outside trusted server code.

3. Inspect database security.

• Review every table that stores user data.
• Confirm Row Level Security is enabled on sensitive tables.
• Check policies for read, insert, update, and delete access.

4. Review logs and recent deploys.

• Look at Supabase logs, hosting logs, and Cloudflare logs if present.
• Identify when the exposure started and whether it matches a recent Lovable publish.

5. Audit frontend environment variables.

• Separate public variables from private ones.
• Find anything named like `API_KEY`, `SECRET`, `SERVICE_ROLE`, `PRIVATE_KEY`, or vendor tokens.

6. Check auth flow screens.

• Test signup, login, logout, password reset, onboarding redirects, and protected routes.
• Confirm unauthenticated users cannot reach app pages by direct URL.

7. Verify third-party integrations.

• Email providers, OpenAI-like APIs, analytics tools, payment gateways, and webhooks often leak secrets first.
• Confirm each integration is called from a safe backend boundary.

8. Freeze deploys until scope is clear.

• If the app is actively leaking secrets or data, stop new releases until keys are rotated and access rules are fixed.

A quick diagnosis command I would run locally:

grep -RInE "service_role|secret|api_key|anon|SUPABASE" .

This does not solve the issue by itself. It tells me where secrets may be hardcoded or referenced in places they should never live.

Root Causes

1. Secrets were put into client-side env vars.

• In Lovable-style builds this happens when a founder wants fast shipping and copies values into anything that works.
• I confirm it by checking build output, browser bundles, and hosting environment variable exposure.

2. Supabase RLS was left off on one or more tables.

• Without RLS, authenticated users may read or write rows they should never touch.
• I confirm it by inspecting table policies and testing access with an unprivileged account.

3. Auth exists in the UI but not at the data layer.

• A login screen can look correct while APIs still accept unauthenticated requests directly.
• I confirm it by calling endpoints without a session token and checking whether data still returns.

4. Service role key was used in frontend code or shared helpers.

• This is high risk because it bypasses all row-level controls if exposed publicly.
• I confirm it by searching for any use of privileged credentials outside server-only files.

5. Redirects or route guards are only cosmetic.

• Protected pages may hide content visually but still fetch sensitive records on mount.
• I confirm it by opening private routes in incognito mode and watching network requests fire anyway.

6. Webhooks or automation flows trust inbound requests too easily.

• If an automation endpoint accepts requests without signature verification or auth checks, attackers can trigger actions or read data indirectly.
• I confirm it by reviewing webhook handlers for secret validation and origin checks.

The Fix Plan

I would fix this in layers so we do not create a bigger mess while trying to clean up one leak.

1. Rotate every exposed secret immediately.

• Regenerate leaked API keys first: Supabase service role key, third-party API keys, email provider keys, payment secrets if exposed anywhere else.
• Assume anything visible in client code is compromised.

2. Remove private secrets from all frontend surfaces.

• Keep only truly public values in client env vars.
• Move privileged calls into server routes, edge functions, or backend-only jobs.

3. Turn on RLS for every sensitive table in Supabase.

• Start with user profiles, messages, documents, billing records, AI outputs tied to users, and audit logs containing personal data.
• Deny by default unless there is a specific policy allowing access.

4. Add explicit auth checks on every protected action.

• Reads that return private data must require an authenticated user session plus ownership checks where needed.
• Writes must verify identity before insert or update.

5. Refactor dangerous client-side logic into trusted server boundaries.

• Anything involving service role access, payment reconciliation, admin actions, email sending with private templates, or AI tool calls should move out of the browser.

6. Lock down CORS and redirect settings where relevant.

• Only allow known domains for auth callbacks and app origins.
• Remove wildcard origins unless there is a very specific reason not to.

7. Review storage buckets and file access rules if files exist.

• Private uploads should not be publicly readable by default.
• Use signed URLs where appropriate instead of open bucket access.

8. Add monitoring before redeploying again.

• Track failed logins, suspicious request spikes, permission errors as well as 401/403 rates that suddenly drop to zero because auth was bypassed entirely.

9. Rebuild deployment with clean env separation.

• Production secrets should live only in production runtime settings.
• Preview environments should use separate non-sensitive test credentials whenever possible.

10. Hand over a simple security checklist to the founder team after release. That reduces repeat mistakes when new features are added under pressure later.

My rule here is simple: if there is any doubt about whether a secret belongs in the browser, it does not belong there.

Regression Tests Before Redeploy

Before shipping again, I would run targeted tests that prove both secrecy and access control are working.

• Unauthenticated visitor test
• Open protected routes in incognito mode.
• Expected result: redirect to login or show a blocked state with no private data loaded.

• Direct API test
• Call protected endpoints without a session token from Postman or curl against staging only.
• Expected result: 401 or 403 response with no data leakage.

• Cross-user access test
• Log in as User A and try to fetch User B's record IDs where applicable on staging data only.
• Expected result: denied unless explicitly shared access exists.

• RLS coverage check
• Every sensitive table should have RLS enabled before launch approval.
• Acceptance criterion: no customer-owned table remains open by accident.

• Secret scan check
• Search source code and build artifacts for service role keys or vendor secrets before deploy.
• Acceptance criterion: zero private keys present in client bundles or public repos.

• Auth flow test

Test signup, login, logout, reset password, session refresh, expired session behavior, protected route redirect, onboarding completion redirect, mobile login flow, error states for invalid credentials, rate limit behavior after repeated failures

• Business acceptance criteria

| Area | Pass standard | | --- | --- | | Data access | No unauthenticated read/write to private records | | Secrets | No private key exposed in browser code | | Recovery | Rotated keys confirmed active | | UX | Login failure shows clear next step | | Stability | No new errors above baseline after deploy |

I would also keep an eye on support load after launch. If customers start reporting login loops or missing records within the first hour post-release, something still has broken at the boundary between auth and data access.

Prevention

If this happened once during an AI-built launch sprint, it can happen again unless you add guardrails now.

• Security review before every publish
• I would check auth flows, RLS policies, secret handling,

third-party integrations, and file storage rules before any production release.

• Least privilege by default
• Use anon/public keys only where absolutely required।
• Keep admin operations server-side with tightly scoped credentials.

• Monitoring that catches mistakes fast
• Alert on unusual anonymous traffic,

multiple failed logins, sudden spikes in database reads, and unexpected changes to RLS-enabled tables.

• Code review focused on behavior
• Reviewers should ask:

Can this be called without auth? Is any secret leaving the server? What happens if this endpoint gets spammed?

• UX guardrails
• Make authentication states obvious।
• Show loading,

expired session, and permission denied states clearly so users do not keep retrying broken flows.

• Performance guardrails
• Cache only public assets।
• Do not cache personalized responses unless you have strict user-specific cache keys.

For AI-built apps specifically:

• Treat prompt inputs as untrusted text if you use AI features anywhere near customer data。
• Block prompt injection from triggering admin actions or exfiltrating hidden context。
• Keep tool permissions narrow so one bad prompt cannot reach your whole database。

When to Use Launch Ready

Launch Ready fits when the product works but is not safe enough to ship publicly yet.

Use it when:

• You have a Lovable plus Supabase app that functions but leaks risk through weak deployment hygiene。
• You need production DNS、SSL、email authentication、and monitoring fixed quickly。
• You want one clean pass before ads、sales outreach、or investor demos start driving traffic。

What I need from you before kickoff:

• Domain registrar access۔
• Cloudflare access if already connected۔
• Hosting/deployment access۔
• Supabase project owner access۔
• Email provider access if sending transactional mail۔
• A list of all third-party services currently connected۔
• Any known bugs around login、signup、or protected pages۔

If your app already exposed keys or allowed unauthorized access，I would not wait for "later." That delay turns into support tickets，data cleanup work，and lost trust fast。

Delivery Map

References

• https://roadmap.sh/cyber-security
• https://roadmap.sh/api-security-best-practices
• https://roadmap.sh/code-review-best-practices
• https://supabase.com/docs/guides/database/postgres/row-level-security
• https://supabase.com/docs/guides/auth

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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.*