Pay once. Keep it.
One-time purchases. Read online, download the labs, and get free updates whenever a volume is revised. Refund within 14 days if you haven't downloaded the labs or read more than 2 paid steps.
- 120 steps, every lab
- Free updates when revised
- Single volumes you bought are credited
Everything, for everyone you name, on one invoice. Companies outside the US welcome.
Prices in USD. Sales tax added at checkout where it applies. Purchases open to US buyers first.
What exactly do I get?
Every step of the volume, read online after signing in, and its labs as a download: plain Python that runs offline. Updates to that volume are free, whenever it's revised.
What's the refund rule?
A full refund within 14 days, as long as you haven't downloaded the labs and have read no more than 2 paid steps. Duplicate purchases and technical problems are always refunded. Details.
I bought one volume. Can I upgrade to all 10?
Yes. What you paid for single volumes is credited, so after one $29.99 volume the rest cost less.
Can I buy from outside the US?
Not yet for individuals; everything free works everywhere. Companies anywhere can buy by invoice: see Teams.
Do I need an API key or a GPU for the labs?
No. The labs run offline with scripted models, so results repeat exactly. A few can optionally call a real model if you add your own key.