A startup shipping subscription billing in 2 days

Illustrative scenario — Tierux is pre-launch. This shows how a team would use Tierux, not a named customer.

The team — a CTO and two full-stack engineers building a health-tracking mobile app — had a launch deadline three weeks away. They needed subscription billing on both Android and iOS: Google Play Billing integration, StoreKit 2 purchase verification, a paywall that could be updated without an app release, and server-side entitlement checks to gate premium features.

Their initial estimate from researching the build: two to three weeks. Google Play Console setup, Google Cloud Pub/Sub for RTDN, App Store Connect configuration, purchase token verification logic, a token vault, webhook processing, and client-side billing SDK integration on both platforms. That was before the paywall UI.

The approach: one MCP prompt

Instead of building from scratch, the CTO connected the Tierux MCP server to Claude Code. They wrote one prompt:

Set up Google Play billing for our health app with a Pro Monthly
plan ($9.99) and Pro Annual plan ($79.99).
Map both to a "pro" entitlement.
Build a paywall showing both plans.
Verify purchases server-side from our Node.js backend.
Test with a real purchase to confirm end-to-end.

The agent handled the entire setup — enabling the Google Play Developer API, creating the service account, configuring the Pub/Sub topic, registering products in Play Console, mapping them to the entitlement, and generating the paywall configuration. Each step showed a preview before persisting. The whole setup — from prompt to verified end-to-end test — took under 15 minutes.

Server-side integration: one afternoon

With the MCP setup complete, the team spent the remaining day wiring up the client SDKs and writing the backend verification endpoint:

// Node.js backend — verify and gate
app.post('/verify-purchase', async (req, res) => {
  const result = await fetch('https://tierux.com/api/v1/purchases/google-play/verify', {
    method: 'POST',
    headers: { 'Authorization': 'Bearer ' + TIERUX_KEY },
    body: JSON.stringify(req.body),
  }).then(r => r.json());

  // result = { active: true, entitlement: "pro", expiresAt: "..." }
  res.json({ canAccess: result.active });
});

They launched on time, with server-side verified subscriptions, a remotely configurable paywall, and automated RTDN processing for renewal and cancellation events. The two-day integration saved them roughly two weeks of engineering time — time they spent on their core health-tracking features instead.

What made the difference

• MCP-first: No clicking through cloud consoles. The agent handled Google Cloud and Play Console setup programmatically.
• Server-side verification from day one: No client-side checks to replace later. The entitlement model was consistent from launch.
• Flat pricing: At their current scale (under 500 subscribers), billing infrastructure is free. As they grow, costs stay predictable — no revenue-share surprise.

"We spent two days on billing instead of two weeks. Our competitors are still clicking through Play Console setup screens while we are shipping features."

Results