How I Would Fix exposed API keys and missing auth in a Supabase and Edge Functions mobile app Using Launch Ready.

How I Would Fix exposed API keys and missing auth in a Supabase and Edge Functions mobile app Using Launch Ready

The symptom is usually obvious: the app works, but sensitive calls are happening without real user checks, and a key is sitting in the client bundle, logs, or a public repo. In business terms, that means anyone can replay requests, scrape data, burn your quota, or trigger actions your users never approved.

The most likely root cause is a prototype that grew into production without a security pass. The first thing I would inspect is the mobile build output and the Supabase project settings side by side: where the key lives, whether RLS is actually on for every table, and whether the Edge Functions are trusting caller input instead of verifying identity.

Triage in the First Hour

1. Check the mobile app source for hardcoded secrets.

• Search for `service_role`, `anon`, API keys, webhook secrets, and `.env` usage.
• Confirm whether any secret was committed to Git history or shipped in the bundle.

2. Inspect Supabase Auth settings.

• Verify sign-in methods, JWT expiry, redirect URLs, and MFA if enabled.
• Check whether user sessions are being created correctly on device.

3. Review every table policy in Supabase.

• Confirm Row Level Security is enabled on all user-facing tables.
• Look for tables with no policies or overly broad policies like `using (true)`.

4. Audit Edge Functions entry points.

• Identify which functions accept unauthenticated requests.
• Check whether they validate JWTs before reading or writing data.

5. Review logs and function invocations.

• Look for spikes in request volume, repeated failures, or calls from unknown origins.
• Check p95 latency and error rate to see whether bad retries are compounding the issue.

6. Inspect build and deployment artifacts.

• Review the latest mobile release, CI logs, and environment variable injection.
• Confirm secrets are not included in debug builds or source maps.

7. Rotate anything exposed before you do anything else.

• Treat leaked keys as compromised.
• Revoke old credentials, issue new ones, and invalidate sessions if needed.

A quick check I often run during triage looks like this:

grep -RniE "service_role|anon|apikey|secret|supabase" .
supabase db diff
supabase functions logs

Root Causes

| Likely cause | What it looks like | How I confirm it | |---|---|---| | Secret stored in the mobile app | Key appears in JS bundle, env file, or repo history | Search source, built artifacts, and Git history | | RLS disabled or incomplete | Users can read or write records they do not own | Inspect each table policy in Supabase | | Edge Function trusts caller input | Function accepts `user_id` from request body without checking JWT | Review function code and auth headers | | Service role key used on client | App can bypass normal access controls | Search for privileged keys outside server-only code | | Missing auth middleware | Public endpoints perform sensitive actions with no session check | Test endpoints with no token or an invalid token | | Weak deployment hygiene | Old builds still point to old secrets or public configs | Compare staging vs production env vars and release notes |

The biggest mistake here is assuming one fix will solve everything. If a leaked key exists and auth is missing, you have two separate problems: credential exposure and authorization failure. I would treat both as production incidents.

The Fix Plan

1. Rotate exposed credentials immediately.

• Replace any leaked Supabase keys, third-party API keys, email provider keys, webhook secrets, and signing secrets.
• If the service supports it, revoke old tokens instead of just creating new ones.

2. Move privileged logic out of the client.

• The mobile app should only use the public Supabase anon key plus authenticated user sessions.
• Any admin-level action should live behind Edge Functions with server-side validation.

3. Enforce authentication at every sensitive Edge Function.

• Require a valid JWT on entry.
• Derive identity from the verified token, not from request body fields like `user_id` or `role`.

4. Turn on RLS everywhere it matters.

• Every table that stores user data should require row ownership or explicit scoped access.
• Start with deny-by-default policies and add exceptions only where needed.

5. Narrow each policy to one business rule.

• For example: users can read their own profile row only.
• Avoid broad policies that accidentally expose other tenants' data.

6. Replace direct writes with safe server-side flows where needed.

• If an action has business impact such as billing updates, notifications, credits, or status changes, route it through an authenticated function that validates input carefully.

7. Add input validation at the edge boundary.

• Validate type, length, format, enum values, and expected ranges before any database call.
• Reject unexpected fields rather than ignoring them silently.

8. Clean up environment handling across environments.

• Separate dev, staging, and production secrets.
• Make sure production builds only receive production-safe variables.

9. Add rate limiting and abuse controls where possible.

• Protect public endpoints from brute force retries and spam traffic.
• This matters because exposed endpoints often get hammered once they are discovered.

10. Verify logging does not leak sensitive data.

• Remove tokens, full payloads, passwords, OTPs, and payment details from logs.
• Keep enough context to debug without exposing customer data.

My recommendation is to fix this in one controlled sprint rather than patching piecemeal over several days. Piecemeal changes usually create broken onboarding flows, duplicate records, support tickets from locked-out users, and a second round of emergency edits.

Regression Tests Before Redeploy

I would not ship until these checks pass:

• Authentication tests
• Unauthenticated requests to protected functions return 401 or 403.
• Valid signed-in users can only access their own records.

• Authorization tests
• A user cannot read another user's row by changing IDs in the request payload.
• Admin-only operations fail for normal users.

• RLS tests
• Every relevant table has RLS enabled.
• No policy allows broad read/write access unless it is explicitly intended.

• Secret exposure tests
• No privileged key exists in client code or built artifacts.
• No secret appears in logs or analytics events.

• Mobile flow tests
• Login still works after rotation of credentials.
• Sign-out clears session state correctly on iOS and Android builds.

• Edge Function tests
• Invalid JWTs fail cleanly.
• Bad input returns structured errors without stack traces.

• Smoke tests after deploy
• Create account -> sign in -> load profile -> update safe field -> confirm persistence.
• Trigger one protected function from a real device build.

Acceptance criteria I would use:

• Zero exposed privileged secrets in client deliverables.
• 100 percent of sensitive tables have RLS enabled with reviewed policies.
• All protected Edge Functions reject unauthenticated calls within 200 ms p95 at normal load.
• No critical auth bypass found in manual test cases across iOS and Android builds.

Prevention

If I were hardening this so it does not come back next month:

• Put secrets scanning into CI so leaks fail fast before merge.
• Require code review for any auth-related change or policy update.
• Keep service role usage server-only with documented exceptions only when absolutely necessary.
• Add runtime monitoring for unusual function invocation spikes and failed auth bursts.
• Track p95 latency on functions so security checks do not quietly degrade performance past 300 ms p95 under normal load.
• Maintain a small security test set covering unauthenticated access, ID tampering, expired tokens, malformed payloads, and replay attempts.

From a UX angle, do not punish legitimate users because of weak backend design. Clear error states matter: if auth fails after token expiry or device refresh issues occur during release rollout delays of even 15 minutes can create support noise fast. Tell users what happened without exposing implementation details.

From a code review lens:

• Review behavior first: who can do what?
• Then review trust boundaries: what comes from the device versus what must be verified server-side?
• Then review maintainability: can another engineer safely change this without reopening the hole?

When to Use Launch Ready

Launch Ready is the right fit when you need me to secure and ship fast instead of turning this into a long internal project.

Use it when:

• You already have a working mobile app but cannot trust its current security posture.
• You need exposed keys rotated immediately before more damage happens .
• Your Supabase setup needs auth hardening plus safe deployment hygiene .
• You want one senior engineer to clean up launch risk without dragging this into weeks of churn .

What you should prepare:

• Repo access plus CI/CD access .
• Supabase project access .
• A list of all third-party services connected to the app .
• Any known leaked keys or suspicious logs .
• The current mobile build status for iOS and Android .
• A short description of which actions must remain public versus authenticated .

If you hand me those items early , I can spend time fixing risk instead of chasing permissions . That usually saves at least one day of back-and-forth .

References

1. roadmap.sh API Security Best Practices: https://roadmap.sh/api-security-best-practices 2. roadmap.sh Cyber Security Roadmap: https://roadmap.sh/cyber-security 3. Supabase Auth Docs: https://supabase.com/docs/guides/auth 4. Supabase Row Level Security Docs: https://supabase.com/docs/guides/database/postgres/row-level-security 5. Supabase Edge Functions Docs: https://supabase.com/docs/guides/functions

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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.*