sin(x)

BuiltBySin is a software and AI development company.

We build self-serve products that do one job well: you pay, you get it, it works. No waiting on a person, no back-and-forth.

See our products Visit the shop

Products

What we've built

forge(party)One-Shot Forge

Custom tabletop RPG one-shot adventures built around your party's level, characters, and tone. Delivered as a ready-to-run PDF.

$35 · Get it →
whodunit(guests)Whodunit Kits

Personalized murder mystery party kits with your guests as the suspects. Host guide, character booklets, and clue cards, delivered by email.

$25 · Get it →
next()In development

More self-serve software and AI tools are in the works.

Soon

How we build

Every product follows the same three rules

PAY

Secure checkout

Payments run through Stripe. We never see or store your card details.

GET

Instant delivery

Your order arrives automatically by email, usually within minutes.

USE

Yours to keep

Files are yours to download, print, and reuse for your own table or party.

Support

Need help with an order?

Email support support@builtbysin.com
  • Include your order email and the product name.
  • Didn't get your delivery? Check spam first, then email us.
  • Refunds follow our refund policy.
  • We reply within 2 business days.