Add more only if you want it. No subscription, and credit never expires.
Access to the app is free: signing up, the simulator, the puzzles, the Layout Designer and the parts list cost nothing. Only the AI features use AI Credit.
Free no fee to sign up or use the app
$5 free to start, then pay as you go
Add credit from the AI gauge in the simulator or the Layout Designer. The bigger the pack, the bigger the bonus.
Payments are processed securely by Stripe; we never see or store your card details. Prices are in US dollars. Charges appear as IRON ROD AI* MODELRAIL.
AI is measured by how much it reads and writes, so each request uses a different amount. A small change at Low effort uses a few cents. Building a whole layout, reading a picture, a long conversation or a higher effort setting uses more, or sometimes several dollars for a large request. Low effort works well for most changes.
The AI gauge shows what you have left, and about what your last request used. It goes from green to red as it runs down, and offers more before you run out. Your Account page lists every purchase, with its receipt, and what your AI requests used.
Yes. Signing up and using the app are free, with no time limit: you only ever pay for AI, and your first $5 of it is on us once you confirm your email.
No. Driving, the puzzles, free play, building layouts by hand and the parts list never use AI Credit.
No. You buy a pack when you want one, and it never renews by itself.
No. It stays on your account until you use it.
Yes. Post about modelrailsim on social media and email a screen capture of the post, with your username, to social@modelrailsim.com: we add $1 of AI Credit for each one. Testers get AI Credit too (testers@modelrailsim.com). See the Messages on the home page.
Yes. Payments go through Stripe's secure checkout, and your card details go straight to Stripe: we never see or store them. Charges appear on your statement as IRON ROD AI* MODELRAIL, and Stripe emails your receipt.
On your Account page: your balance, every purchase with its receipt, and a history of what was added and what each AI feature used.
If a purchase goes wrong, email billing@modelrailsim.com and we'll put it right. AI Credit is added as soon as you pay; in the EU and the UK, the 14-day right to cancel ends once it's added, as checkout explains. See the Terms.
No. AI Credit stays with the account it's on, and it has no cash value.
It goes with the account, so use it first. Credit stays as long as your account is open.
Email billing@modelrailsim.com and we'll put it right.
