01 / CONNECT
Connect your channels
Shopify first, then eBay and Amazon. No CSV files, no field-mapping homework — sensible defaults, and unmapped items are surfaced, never guessed.
CountProof keeps one honest stock count across Shopify, eBay and Amazon — every sale, restock and correction posted to a ledger you can actually read. So the last unit sells once. Not twice. Not three refunds and a suspended seller account.
✓ posted 1.2s ago · every line kept, nothing overwritten
These are real one-star reviews of the most-installed marketplace sync apps — from this year. The pattern repeats: counts drift, syncs stop, support goes quiet.
“Inventory sync between Shopify and eBay is not functioning reliably… a significant risk of overselling. Multiple support requests, no resolution timeline.”
Shopify's own sync app · May 2026“Amazon just stopped syncing and I could not get it fixed. Every 3 months they update and overwrite my settings.”
A leading sync app · January 2026“Over 300 SKUs across channels has become a nightmare. I've oversold products I didn't have.”
Shopify Community · 2025“Amazon's own free app. Two-point-eight stars from a hundred sellers. That's the incumbent.”
The bar we're clearing · 2026The broken apps poll a number every half hour and paste it over the top — which is exactly how a sale in the gap gets erased. CountProof posts movements to a ledger, like a bookkeeper, so two sales can never clobber each other.
Shopify first, then eBay and Amazon. No CSV files, no field-mapping homework — sensible defaults, and unmapped items are surfaced, never guessed.
A sale anywhere writes one line to the ledger and updates every other channel — in real time, not on a 30-to-60-minute cycle. Marketplace orders flow into Shopify so you pack from one screen.
Every count change shows what changed, where, why and when — with each push and its confirmation. When a number looks off, the answer is one line away, not a support ticket away.
If stock hits zero and a channel hasn't confirmed the zero, that listing is paused until it's safe. Your Amazon and eBay account health is not something we gamble with.
CountProof opens first for Shopify ↔ eBay, Amazon next. The founding 25 lock: