We build apps that power your store.
We build AI-powered Shopify apps that help merchants prevent overselling, protect against bots, and boost conversions.
5-minute setup · 14-day trial
Trusted by 20+ Shopify stores running drops
Cart Reserve
Stock held from the first click
Reserve at add-to-cart. Hold through checkout. Release the second they leave.
How it works
Two shoppers. One last unit.
Whoever carts first holds it. The second shopper finds out immediately, not after paying.
- Soft, hard, or drop mode — from a simple timer to parking real Shopify inventory.
- Auto-release on expiry — abandoned holds return to stock automatically.
- Per-product rules — protect the drop, leave the catalogue alone.
Bot protection
Bots don't get a hold.
Every request is scored before a hold is issued. A script can't sit on your drop.
- AI bot detection on every reservation request.
- IP & country blocking with per-IP hold limits.
- Fail-safe access — if scoring is unavailable, real customers still check out.
The cost
What one oversold drop actually costs you.
At 80 oversold units.
Money back out the door after an oversold drop.
Apology emails, order edits and manual refunds.
One plan, no refunds to process, no support queue.
Who we are
We're three engineer brothers in Brno. We built Cart Reserve to help Shopify merchants stop overselling and protect every drop.
The R3Stack brothers
Pricing
Start free. Scale when your drops do.
Paid plans include a 14-day trial. Billed through Shopify.
Your next drop doesn't have to end in refunds.
Install Cart Reserve before your next launch. It takes 5 minutes.