A bot that takes real money and delivers reliably. This is the hard version of the job, and it's what I'm best at.

Everything in the Chatbot Build, plus a payment path designed around one rule: a customer who pays must never lose their money, and must never be charged or delivered twice.

That means idempotent fulfillment — a replayed webhook is caught and ignored. Atomic balance operations, so two simultaneous purchases can't both succeed. Automatic refunds when delivery fails after a successful charge, without the customer having to ask. And server-authoritative design, so the client sends intent and never outcomes.

It ships with a unit and end-to-end test suite that runs against a real database and gates deployment, because the failure modes here are the kind you can't find by reading code.

YOU GET • Everything in the AI Chatbot Build • Telegram Stars or Stripe integration • Idempotent fulfillment with event deduplication and a unique charge constraint • Atomic balance operations • Automatic refunds on post-charge failure • HMAC request authentication • Unit and end-to-end test suite gating deploys • Health endpoint reporting uptime, spend, and service state

WHY IT COSTS WHAT IT COSTS A payment system that works when everything goes right takes a weekend. One that holds when the process dies mid-transaction is the actual job.