Your AI writes the code.
LaunchCheck makes it production-ready.
An MCP server your coding agent calls before shipping. It returns the senior-engineer pattern — correct Stripe webhooks, working auth flows, email that actually delivers — before a line is written.
User: Add Stripe Checkout to this Rails app
→ Calling launchcheck.find_skill(
query: "stripe checkout",
stack: "rails"
)
✓ Skill: rails-stripe-checkout loaded
→ Reading: Common AI mistakes…
→ Implementing with webhook verification
→ Idempotent event processing
→ Test keys in dev, live keys in prod
✓ Done. Checklist: 8/8 items verified.## Common AI mistakes to avoid
- Parse JSON AFTER verifying signature,
never before
- Read request.body once before Rails
middleware consumes it
- Skip CSRF on webhook controller
- Persist event.id — same event fires
twice on Stripe retry
- sk_live_* must never appear in source
## Done when
- [x] Webhook verifies signature
- [x] Idempotency via processed_events
- [x] CSRF skipped on /webhooks/stripe
- [x] Live keys in prod credentials only
AI agents ship the same broken patterns.
Every single time.
Stripe webhooks with no verification
Anyone who learns the endpoint URL can post fake events and fulfill arbitrary orders. The agent never warns you.
Auth with no password reset
Rails 8 built-in auth intentionally excludes password reset. Users who forget their password are locked out forever.
Email that silently never sends
Queue adapter set to :async
in production. Jobs die on restart. No errors, no warnings.
Live API keys in test code
Test-mode Stripe keys in production. Live keys in dev. Hardcoded secrets committed to git. The agent doesn't notice.
Connect once. Correct code, every time.
LaunchCheck is an MCP server. Your coding agent calls it before implementing any external service. It returns the canonical pattern — with the exact footguns AI keeps hitting, listed explicitly.
Connect the MCP server
One command adds LaunchCheck to Claude Code, Cursor, or Windsurf. Works with any MCP-compatible agent.
Agent calls a skill
Before writing code for Stripe, auth, email, or deploys — the agent calls
find_skill
and reads the production-grade pattern first.
Code is correct from the start
The skill includes implementation samples, a done-when checklist, and a list of the exact mistakes AI keeps making. No retrofitting later.
Skills for the stacks
AI agents actually build with.
- Stripe Checkout + webhooks
- Supabase Auth patterns
- Environment variable safety
- Server action security
- Edge function deploys
- Stripe webhook verification
- JWT auth best practices
- Email delivery (Resend, SES)
- Background job patterns
- Docker + Railway deploys
- Stripe with stripe_event gem
- Devise Confirmable setup
- Solid Queue + Solid Cable
- ActionMailer delivery
- Kamal secrets handling
- Stripe webhook handling
- phx.gen.auth + extensions
- Oban background jobs
- Swoosh email providers
- Fly.io release commands
The parts of your app that
most often ship broken.
Payments
Stripe Checkout, subscriptions, webhook signature verification, idempotent event handling, test-vs-live key separation.
Authentication
Login flows, email confirmation, password reset (the part generators leave out), rate limiting, session security.
Email delivery
Postmark, Resend, SES — wired correctly so emails actually send in production, with proper background delivery.
Background jobs
Queue adapters that survive restarts. Sidekiq, Solid Queue, Oban — configured so jobs don't silently disappear.
Deployment
Kamal, Fly.io, Render, Railway — migrations on deploy, non-root containers, secrets not committed, health checks wired.
File uploads
S3 / R2 storage, content-type validation, variant processing — files that don't vanish on redeploy and don't accept arbitrary uploads.
One command. Works everywhere.
$ claude mcp add launchcheck \
https://launchcheck.dev/mcp
✓ LaunchCheck MCP server added
→ Skills available: 40+
→ Stacks: react, node, rails, phoenix# .cursor/mcp.json
{
"mcpServers": {
"launchcheck": {
"url": "https://launchcheck.dev/mcp"
}
}
}# CLAUDE.md
Before implementing any payments, auth,
email delivery, file uploads, background
jobs, webhooks, or deployment config:
call launchcheck.find_skill first.launchcheck.find_skill(
query: "stripe webhooks",
stack: "node"
)
→ node-stripe-webhooks
→ node-stripe-checkout
→ node-stripe-subscriptions
Simple pricing.
One year of access.
- ✓ 40+ production-grade skills
- ✓ React, Node.js, Rails, Phoenix
- ✓ Claude Code, Cursor, Windsurf
- ✓ Payments, auth, email, jobs, deploys
- ✓ 12 months of skill updates
- ✓ Everything in Solo
- ✓ Unlimited teammates
- ✓ Shared team MCP connection
- ✓ Priority support
Frequently asked questions
A skill is a markdown file with everything your coding agent needs to implement a feature correctly: setup steps, complete code samples, a done-when checklist, and a list of the specific mistakes AI keeps making. Your agent reads the skill, then writes the code.
Any agent that supports MCP: Claude Code, Cursor, Windsurf, and anything else in the growing MCP ecosystem. LaunchCheck is a standard MCP server — one URL, connects everywhere.
You could. But LaunchCheck skills are maintained as frameworks and APIs change — Stripe ships new API versions, Rails 8 changed the auth generator, Next.js 15 changed server actions. Writing and updating these patterns across four stacks is a full-time job. The value is curation and maintenance, not just the words.
Yes. The MCP tool descriptions instruct the agent to call LaunchCheck before implementing external services. But adding a short rule to CLAUDE.md or .cursorrules makes the behavior more consistent and explicit.
The MCP server stays active. Skills are frozen at the version from your last active day — you keep using them indefinitely. Renew for another year at $99 to get updated skills as frameworks evolve.
Stop debugging what the
AI should have gotten right.
One MCP connection. Every feature your agent builds — payments, auth, email, deploys — done correctly from the start.