How I Would Fix exposed API keys and missing auth in a Circle and ConvertKit mobile app Using Launch Ready.

How I Would Fix exposed API keys and missing auth in a Circle and ConvertKit mobile app Using Launch Ready

The symptom is usually simple to spot: the app works, but the wrong people can call paid or private endpoints, and one or more API keys are sitting in the mobile bundle, logs, or a public repo. In a Circle and ConvertKit mobile app, that usually means membership data, email actions, or automation triggers can be reached without proper server-side checks.

The most likely root cause is that the app was built fast with direct client-to-vendor calls, then auth was added later as a UI layer instead of a backend control. The first thing I would inspect is whether the mobile app is sending Circle or ConvertKit credentials from the device, because if it is, those secrets are already compromised and must be rotated before anything else.

Launch Ready is the sprint I use when the product needs domain, email, Cloudflare, SSL, deployment, secrets, and monitoring fixed in 48 hours. For this kind of issue, I would treat it as a production safety job first and a launch job second.

Triage in the First Hour

1. Check whether any API keys are present in:

• Mobile source code
• Environment files
• Build logs
• Crash reports
• Analytics events
• Public Git history

2. Review recent deploys and release tags.

• Identify the exact build that introduced the leak or removed auth.
• Confirm whether the issue exists in iOS, Android, or both.

3. Inspect auth flow screens.

• Login
• Sign up
• Password reset
• Deep links
• Subscription or membership gates

4. Check backend and vendor access paths.

• Circle API usage
• ConvertKit API usage
• Any direct calls from the app to third-party endpoints

5. Review logs for sensitive data exposure.

• Authorization headers
• Access tokens
• Email addresses
• Membership IDs
• Webhook payloads

6. Confirm current secret ownership.

• Who has access to Circle and ConvertKit admin panels?
• Which keys are active?
• Which keys can be revoked without breaking production?

7. Verify user impact.

• Can anonymous users reach protected screens?
• Can they trigger email sends or list changes?
• Can they read member-only content?

8. Freeze risky changes.

• Pause releases.
• Pause ad spend if onboarding or conversion flows are broken.
• Disable any automation that might spam users until auth is fixed.

A quick diagnostic check I would run on the codebase is:

grep -RIn "circle\|convertkit\|api[_-]key\|secret\|token" .

That does not solve anything by itself, but it quickly shows where secrets may be hardcoded or referenced in unsafe places.

Root Causes

| Likely cause | What it looks like | How I confirm it | |---|---|---| | Secrets shipped in the mobile app | API key appears in JS bundle, native config, or public repo | Search source history, built assets, and release artifacts | | Missing backend auth checks | Protected actions work if called directly | Test endpoints with no session or an expired session | | Client talks directly to Circle or ConvertKit | App sends vendor key from device | Inspect network calls and bundle contents | | Weak role checks | Free users can access member actions | Test different account types against same endpoint | | Broken token handling | Tokens stay valid too long or are reused across devices | Review token expiry, refresh logic, and logout behavior | | Webhook trust without verification | Incoming events accepted without signature checks | Compare webhook handler against vendor signing docs |

The business risk here is not theoretical. If an exposed key lets anyone trigger email sends or access membership data, you get support load, customer trust damage, possible privacy complaints under GDPR or UK GDPR, and wasted ad spend from traffic entering a broken funnel.

The Fix Plan

1. Revoke exposed secrets immediately.

• Rotate every leaked Circle and ConvertKit key.
• Assume anything already in a client build is public forever.
• Replace old keys only after confirming all active environments use new values.

2. Move vendor access behind your backend.

• The mobile app should never hold privileged Circle or ConvertKit secrets.
• Create server endpoints that validate user identity first.
• Let the backend call Circle or ConvertKit on behalf of the user.

3. Enforce auth on every protected route.

• Check session token on each request.
• Verify user role before returning private data.
• Reject requests early with clear 401 or 403 responses.

4. Add least-privilege service accounts where possible.

• Use separate keys for staging and production.
• Limit permissions to only what each service needs.
• Keep admin-level credentials out of routine app flows.

5. Lock down environment management.

• Move secrets into proper environment variables or secret storage.
• Remove them from code comments, sample files, CI output, and build scripts.
• Confirm they are excluded from source control.

6. Secure webhooks and callbacks.

• Verify signatures where supported.
• Reject unsigned events.
• Make webhook handlers idempotent so retries do not double-send emails or duplicate memberships.

7. Add Cloudflare protection at the edge if there is any public web surface involved.

• Enable WAF rules for obvious abuse patterns.
• Turn on rate limiting for login and webhook routes where appropriate.
• Use SSL everywhere and force redirects to HTTPS.

8. Clean up deployment hygiene with Launch Ready standards.

• Confirm DNS points to the correct environment only after validation.

`www`, apex domain redirects, subdomains like `api` and `app`, SSL certs, caching rules, DDoS protection, SPF/DKIM/DMARC for email deliverability, uptime monitoring, deployment checklist, rollback path.

9. Add explicit auth failure states in the app UI. If a session expires or access is denied, show a clear screen instead of letting users tap into broken views. That reduces confusion and support tickets when protected content becomes unavailable after rotation.

10. Deploy in one controlled pass only after verification. I would not "hotfix" this by patching just one screen while leaving vendor calls exposed elsewhere. The safer path is one small release that removes client-side secrets, adds server enforcement, rotates credentials, and verifies all protected flows together.

Regression Tests Before Redeploy

I would not redeploy until these checks pass:

• Anonymous user cannot reach any protected screen or action.
• Expired session returns 401 consistently across all protected endpoints.
• Wrong role returns 403 consistently across all restricted actions.
• Mobile app contains no live Circle or ConvertKit secret in source or build output.
• Backend rejects unsigned webhook requests where signature verification exists.
• Rotated old keys no longer work anywhere in staging or production tests.
• Login logout login cycle works on iOS and Android without stale access surviving logout.
• Member-only content cannot be fetched through deep links without auth.
• Email-triggering actions require server-side permission checks before calling ConvertKit.

Acceptance criteria I would use:

• Zero exposed privileged keys in shipped artifacts.
• 100 percent of protected endpoints require server-side auth checks.
• No direct privileged vendor calls from mobile clients.
• P95 response time for auth-protected endpoints stays under 300 ms after adding backend validation and caching where appropriate.
• Smoke tests pass on at least 2 devices per platform before release.

I would also run one manual exploratory pass:

• Try an incognito-style unauthenticated path equivalent on mobile if available."
• Force token expiry."
• Switch between free and paid accounts."
• Replay a webhook event."
• Tap back-and-forth through onboarding after logout."

Prevention

The fix only holds if you add guardrails around it.

• Code review:

Every change touching auth, secrets, webhooks, billing-like flows, or vendor integrations gets senior review before merge.

• Security:

Secrets live only server-side unless they are explicitly public identifiers with no privilege attached. Rotate them on a schedule and immediately after any leak.

• Monitoring:

Alert on repeated 401s/403s spikes, unusual webhook volume, failed login bursts, unexpected email send counts, new deployments that change auth routes, uptime drops on login and checkout-like screens.

• Logging:

Never log raw tokens, API keys, authorization headers, password reset links, full webhook payloads containing sensitive data.

• UX:

Show clear states for logged out, expired session, insufficient permissions, failed sync, maintenance mode, network timeout."

• Performance:

Keep auth checks lightweight so they do not create slow screens that frustrate users into retrying actions multiple times."

A good rule I use: if a developer can explain why a secret must exist in a mobile client without saying "public identifier only," it probably should not be there.

When to Use Launch Ready

Use Launch Ready when you need this fixed fast without turning your product into a bigger rebuild project. The sprint covers domain setup, email deliverability basics like SPF/DKIM/DMARC, Cloudflare, SSL, deployment, secrets handling, monitoring,

For this specific failure mode," I would use it when:

• Your app is already built but unsafe to ship."
• You need to rotate leaked credentials before launch."
• You want production deployment cleaned up at the same time as security fixes."
• You have paid traffic waiting but cannot safely send users into a broken auth flow."

What I need from you before starting:

• Repo access"
• Current build pipeline details"
• Circle admin access"
• ConvertKit admin access"
• Domain registrar access"
• Cloudflare account access if already set up"
• A list of environments: dev,"

staging," production"

• Any recent crash logs,"

screenshots," or support complaints"

If your product has already leaked secrets," I will treat that as an incident response sprint inside Launch Ready:" rotate," verify," redeploy," then hand over with a checklist so you do not repeat the mistake."

Delivery Map

References

1. Roadmap.sh Cyber Security: 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. Circle Developer Docs: https://developers.circle.so/ 5. Kit (ConvertKit) Developer Docs: https://developers.kit.com/

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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.*