How I Would Fix exposed API keys and missing auth in a Supabase and Edge Functions founder landing page Using Launch Ready.

How I Would Fix exposed API keys and missing auth in a Supabase and Edge Functions founder landing page Using Launch Ready

The symptom is usually simple to spot: a founder landing page still works, but the browser network tab shows Supabase keys, Edge Function URLs are public, and sensitive actions can be called without any real user check. The most likely root cause is that the app was built fast with client-side calls only, then shipped before auth boundaries, env handling, and function guards were put in place.

The first thing I would inspect is whether the exposed value is actually an anon key or a true secret service role key. That one detail changes the risk level from "fix soon" to "rotate now and assume compromise."

Triage in the First Hour

1. Check the live site in an incognito browser.

• Open DevTools and inspect Network, Sources, and Application tabs.
• Confirm what is visible in JS bundles, request headers, local storage, and any embedded config.

2. Identify every exposed credential.

• Supabase anon key.
• Supabase service role key.
• Edge Function secrets.
• Third-party API keys in frontend code or public repo history.

3. Review Supabase Auth settings.

• Check whether sign-up is open.
• Confirm email confirmation rules.
• Verify MFA or password policy if used.
• Look at row level security status on all tables involved.

4. Inspect Edge Functions logs.

• Look for unauthenticated calls.
• Check repeated requests from the same IPs or user agents.
• Confirm whether functions are trusting client-supplied IDs or roles.

5. Review deployment history.

• Find the commit that introduced the leak.
• Check whether secrets were added to `.env`, build config, or hardcoded in code.
• Confirm if old builds are still being served from CDN cache.

6. Check Cloudflare and hosting settings if present.

• Make sure caching is not serving stale JS bundles with old keys.
• Confirm WAF, rate limiting, and SSL are active.

7. Rotate any secret that could have been exposed.

• If a service role key or third-party API key was public, rotate it before deeper debugging.
• Treat public exposure as a real incident, not a cosmetic bug.

A quick diagnostic pattern I use is:

## Search for hardcoded keys and public env usage
grep -R "supabase\|service_role\|apikey\|secret" .

## Check recent git history for accidental commits
git log --oneline --decorate --graph -n 20

Root Causes

| Likely cause | What it looks like | How I confirm it | |---|---|---| | Service role key used in frontend | Sensitive actions work without login | Search bundle source and network calls for `service_role` usage | | Missing RLS policies | Any signed-in or anonymous user can read/write rows | Inspect table policies in Supabase dashboard | | Edge Function trusts client input | User can pass any `user_id`, `role`, or record ID | Read function code for unchecked body params | | Secrets stored in public build vars | Keys appear in JS bundle or page source | Review framework env naming and built assets | | No auth gate on function endpoint | Function returns data to anonymous requests | Call endpoint without auth header and review response | | Old deploy cached by CDN | Fix exists in repo but live site still leaks old code | Purge cache and compare deployed bundle hash |

The Fix Plan

My approach is to stop the bleeding first, then repair access control at the boundary where it belongs. I would not try to "hide" keys in frontend code, because anything shipped to the browser is effectively public.

1. Rotate exposed secrets immediately.

• Rotate any Supabase service role key if it was ever exposed publicly.
• Rotate third-party API keys used by Edge Functions if they appeared in frontend code or logs.
• If you cannot prove exposure did not happen, assume it did.

2. Move all privileged logic behind server-side checks.

• Keep only the Supabase anon key in the frontend if needed for public reads.
• Put sensitive writes inside Edge Functions or server routes with explicit auth verification.
• Never call admin APIs directly from browser code.

3. Add auth verification to every protected Edge Function.

• Verify JWTs using Supabase auth context before processing requests.
• Reject anonymous requests with 401.
• Reject unauthorized roles with 403.

4. Enforce row level security everywhere sensitive data exists.

• Turn on RLS for all tables that store user data, leads, submissions, billing info, or admin content.
• Create narrowly scoped policies for read/write access only where needed.
• Test both authenticated and anonymous access paths.

5. Remove secrets from client-facing config files.

• Audit `.env`, build-time variables, framework config files, and deployment settings.
• Use separate names for public values versus server-only values so they cannot be mixed up again.

6. Purge caches and redeploy cleanly.

• Clear Cloudflare cache if used.
• Redeploy after rotation so stale bundles stop serving old values.
• Verify source maps are not exposing sensitive strings.

7. Add basic abuse controls at the edge.

• Rate limit form submits and function calls by IP and path.
• Add bot protection where landing page forms attract spam or credential stuffing attempts.

8. Tighten logging so secrets do not leak again.

• Do not log full request bodies containing tokens or PII.
• Redact authorization headers and secret fields from function logs.

If I were doing this as a rescue sprint under Launch Ready, I would keep the scope tight: fix auth boundaries, rotate secrets, redeploy safely, then verify no public path still reaches privileged data.

Regression Tests Before Redeploy

Before shipping anything back live, I want proof that the leak is gone and that normal users can still convert without friction.

1. Anonymous access checks

• Open the landing page without signing in.
• Confirm protected endpoints return 401 or redirect as intended.
• Confirm no private data appears in HTML source, JS bundles, or network responses.

2. Authenticated access checks

• Sign in with a valid test account.
• Confirm allowed actions work end to end: form submit, lead capture, dashboard access if applicable.

3. Authorization checks

• Try one account against another account's records using safe test data only.
• Confirm access fails with 403 or empty results where appropriate.

4. Secret exposure checks

• Search production bundles for rotated keys or secret strings before deploy completion.

```bash grep -R "service_role\|sk_live\|secret\|apikey" dist build .next out ```

5. Function behavior checks

• Test each Edge Function with:

1. no token, 2. invalid token, 3. valid token, 4. wrong-role token if roles exist.

6. Caching checks

• Hard refresh after deploy and confirm old assets are gone.
• Verify CDN cache purge completed successfully.

7. Acceptance criteria

• No secret value appears in browser-visible assets.
• All protected functions reject anonymous calls within 200 ms p95 at the edge under normal load target of 50 requests per minute per IP cap settings permitting legitimate traffic only enough for this type of page).
• RLS blocks cross-user reads and writes on every sensitive table.
• Public landing page still loads under a Lighthouse performance score target of 90+ on mobile after fixes are applied carefully.

Prevention

I would put guardrails in place so this does not come back six weeks later when someone ships a new form or automation flow quickly under pressure.

• Code review guardrail:

Every PR that touches auth, env vars, Edge Functions, or database policies gets reviewed for behavior first: who can call it, what data it returns, what happens on failure.

• Secret handling guardrail:

Separate public config from server-only secrets by naming convention and deployment policy. If a value can pay invoices or read customer data, it never goes into client code.

• Security monitoring:

Alert on unusual spikes in function calls, failed auth attempts, new countries hitting protected routes, repeated 401s/403s, and sudden changes in response size.

• QA guardrail:

Keep a small auth regression suite that runs on every deploy. It should test anonymous access denial, valid login success, RLS enforcement, and form submission behavior.

• UX guardrail:

Show clear loading states when auth is checked so users do not see broken flashes or confusing redirects on mobile devices during sign-in flows.

• Performance guardrail:

Keep landing page scripts light after adding security logic. A common mistake is shipping heavy client-side auth libraries that hurt LCP and increase bounce rate before conversion even starts.

• Incident response habit:

Treat any future secret exposure as an incident with rotation steps documented up front instead of improvising during a launch window.

When to Use Launch Ready

Launch Ready fits when you need this fixed fast without turning your product into a long consulting project.

Use it when:

• Your landing page is live but unsafe to send traffic to yet,
• You found exposed keys or missing auth right before launch,
• You need one senior engineer to fix production risk quickly,
• You want a clean handoff instead of another patchwork deploy cycle.

What I would ask you to prepare:

• Repo access,
• Supabase project access,
• Hosting access,
• Cloudflare access if used,
• A list of all forms, endpoints, automations, and integrations,
• Any current errors from logs or user reports,
• The exact conversion goal for the page so I can preserve it while fixing security.

My recommendation: do not keep iterating blindly on top of an unsafe launch candidate. Fix the boundary first; then optimize copy and conversion after you know customer data cannot leak through a public endpoint again.

References

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

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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.*