Launch Ready API security Checklist for automation-heavy service business: Ready for app review in marketplace products?.

What "ready" means for an automation-heavy marketplace product

For this kind of product, "ready for app review" does not mean "it works on my machine." It means a reviewer can sign up, trigger the core automation, and see predictable behavior without hitting broken auth, missing emails, dead webhooks, or exposed secrets.

I would call it ready only if all of these are true:

• The app deploys cleanly to production with no manual hotfixes.
• Domain, SSL, email auth, and redirects are correct.
• Secrets are not in the repo, logs, or client bundle.
• API endpoints reject bad input and unauthorized access.
• Marketplace reviewers can complete the main flow in under 5 minutes.
• Monitoring is live so you know if onboarding or automation breaks after release.

If any of those fail, you do not have an app review problem. You have a production safety problem that will turn into delays, rejected review cycles, support load, and wasted ad spend.

Quick Scorecard

| Check | Pass criteria | Why it matters | What breaks if it fails | |---|---|---|---| | 1. Domain setup | Root and www resolve correctly, HTTPS only | Reviewers and users trust the product | Mixed content, failed login callbacks | | 2. SSL | Valid cert on all public hosts | Required for secure sessions and APIs | Browser warnings, blocked auth flows | | 3. Redirects | HTTP to HTTPS and non-canonical domains redirect once | Prevents duplicate URLs and SEO issues | Broken links, looping redirects | | 4. Email auth | SPF, DKIM, DMARC all pass | Marketplace emails must land in inboxes | Verification emails go to spam | | 5. Secrets handling | Zero exposed secrets in repo or client code | Stops account takeover and bill shock | Credential theft, API abuse | | 6. Auth checks | No critical auth bypasses; role checks enforced server-side | Protects customer data and admin tools | Data leaks across accounts | | 7. Input validation | All public endpoints validate payloads and limits | Stops bad requests from breaking automation | Webhook failures, injection risk | | 8. Rate limiting | Abuse-prone routes limited by IP/user/token | Protects APIs from spam and brute force | Downtime, cost spikes, lockouts | | 9. Monitoring | Uptime alerts and error tracking active | You need to catch failures before users do | Silent outages during review | | 10. Production deploy | Stable build with rollback path tested | Reviewers need a working live environment | Failed submission, long delays |

The Checks I Would Run First

1. Public surface scan

Signal: I want to know exactly what is exposed to the internet: API routes, admin panels, webhook endpoints, file uploads, and any staging links that should not be public.

Tool or method: I check route maps in the app, inspect reverse proxy config, crawl the site with a browser and a proxy tool like Burp or simple curl scripts, then compare that against intended product surfaces.

Fix path: Remove anything that should not be public, lock staging behind auth or IP allowlists, and make sure only the minimum production routes are reachable. For marketplace products I also verify that reviewer-facing flows are isolated from internal tools.

2. Secret exposure check

Signal: I look for API keys in Git history, environment files committed by mistake, frontend bundles containing private values, logs printing tokens, and CI variables reused across environments.

Tool or method: I run secret scanners on the repo history and current branch, inspect build output for leaked values, and grep logs for tokens or webhook signatures.

Fix path: Rotate any exposed secret immediately. Move sensitive config to server-side env vars only and remove anything that shipped to the browser unless it is truly public.

3. Authz and account boundary test

Signal: I try to access another user's data by changing IDs in requests, replaying tokens after logout, calling admin endpoints as a normal user, and testing whether webhooks can mutate records without verification.

Tool or method: I use manual API calls plus a small test set of negative cases around ownership checks and role checks.

Fix path: Enforce authorization on every write endpoint server-side. Do not trust client claims like `role=admin`, `isOwner=true`, or hidden form fields. If there is tenant data separation failure here, I would stop launch work until it is fixed.

4. Webhook integrity check

Signal: Automation-heavy services often depend on Stripe-like events or third-party webhooks. If those events are unsigned or accepted from anywhere without verification windows or replay protection, your system can be spoofed.

Tool or method: I inspect signature verification logic against provider docs and replay test with invalid signatures and old timestamps.

Fix path: Reject unsigned payloads, verify timestamps within provider tolerance windows where supported, store event IDs to prevent duplicates when needed, and make handlers idempotent so retries do not create duplicate jobs.

5. Email deliverability check

Signal: Marketplace products often fail because verification emails never arrive or land in spam due to broken SPF/DKIM/DMARC setup.

Tool or method: I check DNS records directly and send test messages to Gmail/Outlook/Yahoo inboxes while inspecting headers for authentication results.

Fix path: Publish SPF/DKIM/DMARC correctly for your sending domain and use one mail provider per environment until delivery is stable. For Launch Ready work I treat this as launch-critical because failed email verification kills activation rates fast.

6. Production health check

Signal: A product can pass functional tests but still fail app review if pages load slowly or APIs stall under real traffic. My threshold is p95 API latency under 500ms for core actions and no critical errors during a full review flow.

Tool or method: I use uptime monitoring plus request tracing from a real user journey through signup, login, automation trigger, success state, logout.

Fix path: Add indexes where queries are slow enough to affect p95 latency above target ranges; cache repeated reads; move heavy jobs into queues; reduce third-party scripts; set alerting on error spikes so you hear about failure before reviewers do.

Red Flags That Need a Senior Engineer

1. You have one codebase serving both staging and production with shared secrets.

• This usually means one mistake can leak data across environments.

2. The app uses automation triggers but has no idempotency strategy.

• Duplicate jobs become duplicate charges, duplicate emails, or duplicate records.

3. Admin actions are protected only by frontend UI hiding.

• That is not security; it is decoration.

4. Webhooks change state without signature verification.

• Anyone who discovers the endpoint can fake events unless you block them properly.

5. App review already failed once for "incomplete functionality" or "cannot verify account."

• That usually points to backend instability rather than UI polish.

DIY Fixes You Can Do Today

1. Turn on HTTPS everywhere.

• Force HTTP to HTTPS redirects at Cloudflare or your host.
• Make sure every asset loads over HTTPS so browsers do not block mixed content.

2. Audit your env files now.

• Delete any `.env` file from git history if it contains real keys.
• Rotate every key that was ever committed or pasted into chat tools.

3. Test your email domain health.

• Check SPF/DKIM/DMARC with your DNS provider.
• Send yourself a signup email and confirm it lands in inbox instead of spam.

4. Remove risky public endpoints.

• If you have old preview routes or debug APIs open publicly, disable them before review.
• If you cannot explain what an endpoint does in one sentence, reviewers should not be able to hit it either.

5. Add basic monitoring today.

• Set uptime alerts for homepage login page plus one core API route.
• Add error tracking so you see crashes before users report them.

A simple DMARC baseline looks like this:

v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com; adkim=s; aspf=s

That is not the final answer for every business model, but it is better than having no policy at all while you are trying to pass review.

Where Cyprian Takes Over

• Domain setup failing:
• I fix DNS records, canonical redirects, subdomains ,and Cloudflare settings.
• Timeline: first few hours of day one.

• SSL or mixed content failing:
• I install or repair certificates and remove insecure asset references.
• Timeline: same day as domain cleanup because these issues block review fast.

• Email auth failing:
• I configure SPF/DKIM/DMARC so verification emails actually land.
• Timeline: day one before handover testing starts.

• Secrets exposure:
• I move secrets into proper environment variables,

rotate compromised keys, remove leaks from build output, then verify nothing sensitive ships client-side.

• Timeline: immediate priority because this is security risk plus cost risk if abused.

• API security gaps:
• I harden auth checks,

validate inputs, enforce rate limits, verify webhooks, tighten CORS, reduce logging of sensitive payloads, then retest edge cases.

• Timeline: day one into day two depending on complexity.

• No monitoring:
• I add uptime monitoring plus alert routing so you know if launch breaks after deployment.
• Timeline: end of sprint before handover.

What you get in the sprint:

• DNS
• Redirects
• Subdomains
• Cloudflare
• SSL
• Caching
• DDoS protection
• SPF/DKIM/DMARC
• Production deployment
• Environment variables
• Secrets handling
• Uptime monitoring
• Handover checklist

The point is not just "deployed." The point is "safe enough that an app reviewer can complete the flow without triggering support tickets."

Final self-assessment before app review

If you can answer yes to these questions without caveats ,you are close:

1. Can a new user sign up with no manual intervention? 2. Can they receive email verification within minutes? 3. Can they trigger the core automation once without duplicates? 4. Are all secrets absent from the browser bundle? 5. Are unauthorized users blocked from private data? 6. Is p95 API latency under 500ms for core actions? 7. Are SPF/DKIM/DMARC passing? 8. Is there uptime monitoring on the live environment? 9. Can you roll back safely if deployment breaks? 10. Would you feel comfortable showing this flow to a marketplace reviewer today?

References

• Roadmap.sh Code Review Best Practices: https://roadmap.sh/code-review-best-practices
• Roadmap.sh API Security Best Practices: https://roadmap.sh/api-security-best-practices
• Roadmap.sh QA Roadmap: https://roadmap.sh/qa
• OWASP Top Ten: https://owasp.org/www-project-top-ten/
• Cloudflare DNS documentation: https://developers.cloudflare.com/dns/

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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.*