Restock alerts that never miss.
Kelso emails your customers the moment an out-of-stock product comes back, so Shopify stores stop losing sales to silent waitlists. Two-path restock detection. Paced sends. A full audit log for every alert. Flat pricing, no revenue share, ever.
- BIS-0138QUEUED → SENT → DELIVERED1.8s
- BIS-0139QUEUED → SENT → DELIVERED2.4s
- BIS-0140QUEUED → SENT → DELIVERED1.6s
- BIS-0141QUEUED → SENT → DELIVERED3.0s
- BIS-0142QUEUED → SENT → DELIVERED2.1s
- BIS-0143QUEUED → SENT → DELIVERED1.9s
- BIS-0144QUEUED → SENT → DELIVERED2.7s
- BIS-0145QUEUED → SENT → DELIVERED1.5s
- BIS-0146QUEUED → SENT → DELIVERED2.2s
- BIS-0147QUEUED → SENT → DELIVERED1.7s
- BIS-0148QUEUED → SENT → DELIVERED2.9s
- BIS-0149QUEUED → SENT → DELIVERED2.0s
- BIS-0138QUEUED → SENT → DELIVERED1.8s
- BIS-0139QUEUED → SENT → DELIVERED2.4s
- BIS-0140QUEUED → SENT → DELIVERED1.6s
- BIS-0141QUEUED → SENT → DELIVERED3.0s
- BIS-0142QUEUED → SENT → DELIVERED2.1s
- BIS-0143QUEUED → SENT → DELIVERED1.9s
- BIS-0144QUEUED → SENT → DELIVERED2.7s
- BIS-0145QUEUED → SENT → DELIVERED1.5s
- BIS-0146QUEUED → SENT → DELIVERED2.2s
- BIS-0147QUEUED → SENT → DELIVERED1.7s
- BIS-0148QUEUED → SENT → DELIVERED2.9s
- BIS-0149QUEUED → SENT → DELIVERED2.0s
Restock alerts have a well-documented failure mode.
Search "back in stock app" reviews on the Shopify App Store and the same three complaints show up across the category: mass sends that silently fail during a launch, weeks of downtime with no word from support, and alerts going out for stock that was never actually there. These are not rare. They are the reason merchants switch apps.
We built Kelso against those three failure modes specifically, not as an afterthought.
Webhooks alone drift
Shopify does not guarantee webhook delivery. After 8 failed retries it deletes the subscription. Apps that rely on webhooks alone fall out of sync silently, and nobody notices until a customer complains.
Burst sends get flagged
Restock 500 people at once from one un-paced blast and sending domains get throttled or blacklisted by mailbox providers. The alerts that matter most, the ones for your most-waited-on items, are the ones most likely to get dropped.
No record of what happened
Without a send-by-send log, "did my customers get the email" is a guess. When something goes wrong, most apps cannot tell you what, when, or to whom.
- Two-path restock detection. The inventory webhook fires first, for speed. A scheduled reconciliation poll runs behind it and catches anything the webhook drops. One failure never means a missed restock.
- Paced, queued sending. Alerts go out in batches you control, through a warmed sending domain, not one giant blast. Built specifically against the burst-send failure mode.
- A full send audit log. Every alert is tracked from queued to sent to delivered to clicked. If you ask what happened to a specific alert, we can show you, not guess.
- Flat pricing. One monthly fee for a send allowance. No revenue share, no per-unit fees, no overage charges, ever. Over your limit, sends hold instead of dropping.
- Human support. Emailsupport@kelsohq.com and a person replies in hours. Details on the support page.
Built, submitted, and launching this month.
There is nothing to install today, so the waitlist is the whole ask. Join it and you get one email the day the listing goes live, plus free white-glove migration: send us a CSV export of your current waitlist and we move your subscribers over by hand.
- App builtCode complete and tested(done)
- Shopify reviewIn progress right now
- Live on the App StoreThis month