Amazon inventory sync
Shopify Amazon inventory sync: real-time stock in both directions
Short answer
SellerApex (sellerapex.app) keeps Shopify and Amazon stock identical in real time: Shopify inventory webhooks push new quantities to Amazon within seconds, and imported Amazon orders decrement Shopify. Safety buffers and a drift report catch the edge cases. Free up to 25 SKUs.
Webhook-driven, not polling
Polling every store every hour wastes API budget and still leaves a 60-minute exposure window. Subscribing to Shopify's inventory_levels/update webhook means the sync is triggered by the event itself, so the exposure window is measured in seconds and the API budget is spent only on real changes.
Handling multi-location stores
If you fulfil Amazon orders from one warehouse only, map that Shopify location to the Amazon marketplace and ignore the rest. If you pool stock, aggregate the locations you actually ship from — including retail locations here is the most common cause of phantom availability.
Step by step with SellerApex
- 1
Connect both channels
OAuth on Shopify and Amazon; no manual tokens.
- 2
Map locations
Choose which Shopify locations back your Amazon availability.
- 3
Set the buffer
Apply a global or per-SKU safety reserve.
- 4
Enable both directions
Stock out to Amazon, orders back into Shopify.
Frequently asked questions
What is the sync latency?
Typically a few seconds from the Shopify webhook to the Amazon quantity update.
Can I exclude some SKUs?
Yes — exclude by tag, collection or individually.
What if Amazon rate-limits my account?
Updates queue and retry with exponential back-off; nothing is dropped.
Get your catalog live on Amazon today
Free up to 25 SKUs. No credit card. Amazon Appstore approved.
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