Working code — not a course

Three units left.
Four people click Buy.
Now what?

This is the code that runs my shop and my daily video channel. I don't check stock, send order emails or edit videos. It runs without me. Cleaned up so it can run yours.

Get the Playbook $79.99

Buy once. Yours forever, including every update.

The last three units

on hand: 3 · four checkouts, same millisecond

The ordinary way

Read the stock, then write the order. What almost every shop does.

This code

Lock the cart, take the stock rows in a fixed order, then reserve.

An illustration of the test that ships with the shop engine — it boots a real PostgreSQL, races live connections, and fails if the fix ever stops working. You can run it yourself after you buy.

What you get

Two engines and the guide that explains them.

The shop engine

Takes the money and tells you about it.

Live stock that can't oversell — four people can't buy the last three units
Prices customers can't edit in dev tools
Crypto payments that mark themselves paid. No merchant account needed
Automatic order confirmation emails
Telegram alerts for new orders, low stock and bad reviews — with quiet hours

The content engine

One command: story → script → narration → captions → finished vertical video → scheduled.

Free local voice. Posting more never costs more
Posts on a schedule — your PC doesn't need to be on
Generate a week of content on Sunday
Goes out to TikTok and YouTube
Plus the Playbook: why it's built this way, and the seven rules it runs on

Before you trust any of it

Part of it is free, and you can read it first.

The inventory module is published on GitHub under MIT — the same locking the shop engine uses, with a test suite that boots a throwaway PostgreSQL and races real connections against each other. It also ships the naive version, so you can watch that one oversell in the same scenario.

Read it, run it, break it. Then decide whether the paid half is worth $79.99.

github.com/SoloCron/no-oversell →

git clone https://github.com/SoloCron/no-oversell
npm test

  holds the last unit once ................ ok
  refuses the second buyer ................ ok
  survives two tabs on one cart ........... ok
  never revives a lapsed hold ............. ok

  54 assertions, 0 failures
  PostgreSQL 18.4

What you need

Everything it runs on, before you buy — not after.

For the shop engine

Node 18+ and a free Supabase account
A free Telegram account — that's where the alerts land
An email account with SMTP for the order confirmations (a Gmail app password does it)
A free NOWPayments account if you want the crypto checkout

For the content engine

Windows — the video pipeline is built on it
An Anthropic (Claude) API key, which runs on prepaid credits
An Upload-Post account — free covers 10 posts a month to YouTube and others, and TikTok posting is on their Basic plan from $24/month
Background footage you own or are licensed to use
One setup command that downloads ffmpeg, whisper.cpp and Piper — a few hundred MB, once

If you can edit a config file, you can run this. You don't need to write code.

Set it up once. It runs forever.

The shop engine takes about two hours. The content engine takes about one. After that it is a thing you own, not a thing you pay for again.