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Back-in-Stock Notifier · E-commerce & Retail

Everyone on the waitlist hears the day it's back in stock

Twice a day it checks your waitlist sheet against Shopify stock, and each person waiting for a restocked product gets one email from your Gmail.

Available now $79 one-time · never renewsIncluded in Enterprise
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Free account to start. Buying and running live need a paid plan.

  • Runs on a schedule
  • 1 AI step
  • A person approves before it acts
  • About 20 min to set up

Sound familiar?

The job, before and after this agent.

What it feels like today

  • “People ask to be told when it's back, and the list sits in a spreadsheet nobody checks.”
  • “By the time we email the waitlist, the restock has sold out again.”
  • “We've emailed the same person twice and missed others completely.”

What you get with the agent

  • Each waiting row's product is looked up in Shopify and its variants' stock added up in code.
  • One email per person from your Gmail with their name, the product and its link.
  • You approve the wording for each batch, or switch review off.
  • Rows are marked Notified and each person is remembered per product, so nobody gets it twice.
  • Each run's results are counted in code: emailed, skipped, still out of stock.

Before

The linen apron is restocked on Tuesday; on Friday someone remembers the waitlist and copies addresses into an email.

After

At 15:00 on Tuesday the check sees 12 aprons in stock, you approve the wording, and the 18 people waiting each get a short personal email with the link.

How it works

The whole workflow, step by step.

At 9:00 and 15:00 the agent reads your waitlist sheet (Email, Name, Product, Link, Notified) and, for each row not yet notified, finds the product in Shopify by its title and adds up its variants' stock in code. When something is back, AI writes the email's subject, opening and closing once in your voice, and code adds each person's name, the product and its link. After your approval (or straight away, if you switch review off) each person gets one email from your Gmail. Each emailed row is marked Notified and remembered for a year, so nobody is emailed twice about the same product, and the run is counted in code. Up to 100 rows a run.

  1. TriggerTwice a day (9:00 and 15:00)
  2. App callRead the waitlist
  3. LogicEach waitlist row
  4. LogicAlready notified?
  5. LogicStill waiting?
    • Already notified:Already notified
    • Waiting:Find the product in Shopify
  6. OutputAlready notified
  7. App callFind the product in Shopify
  8. LogicAdd up the stock
  9. LogicBack in stock?
    • Back:Back in stock
    • Still out:Still out of stock
  10. OutputBack in stock
  11. OutputStill out of stock
  12. LogicCount the waitlist
  13. AI stepWrite the back-in-stock email
  14. LogicAnything back in stock?
  15. LogicSend, and review first?
    • Nothing back:Nothing back in stock
    • No review:Check the wording
    • Review first:Approve the back-in-stock email
  16. OutputNothing back in stock
  17. Human approvalApprove the back-in-stock email
    • Approved:Check the wording
  18. LogicCheck the wording
  19. LogicPassed the checks?
    • Send:Each waitlist row
    • Held:Held: nothing sent
  20. OutputHeld: nothing sent
  21. LogicEach waitlist row
  22. LogicBack in stock?
    • Back:Emailed before?
    • No:No email
  23. OutputNo email
  24. LogicEmailed before?
  25. LogicNew?
    • Already emailed:Already emailed
    • New:Check the row
  26. OutputAlready emailed
  27. LogicCheck the row
  28. LogicValid?
    • Valid:Email them
    • Fix the row:Not emailed: check the row
  29. OutputNot emailed: check the row
  30. App callEmail them
  31. App callMark the row Notified
  32. LogicRemember the email
  33. LogicCount the emails
  34. OutputDone

This is the workflow that opens in your workspace when you set the agent up. Every step can be edited.

  1. Step 1Twice a day (9:00 and 15:00)Checks your waitlist against Shopify stock at 9:00 and 15:00. Set your time zone on the trigger; change the times there.
  2. Step 2Read the waitlistReads your waitlist tab (Email | Name | Product | Link | Notified).
  3. Step 3Each waitlist rowChecks up to 100 waitlist rows, one at a time.
  4. Step 4Already notified?In code: a row with a date in Notified was emailed before and is skipped.
  5. Step 5Still waiting?Rows already notified are skipped.
  6. Step 6Already notifiedEmailed in an earlier run.
  7. Step 7Find the product in ShopifyLooks up the product by its title in the Product column, with its variants and inventory.
  8. Step 8Add up the stockIn code, not AI: adds up the inventory of the product's variants.
  9. Step 9Back in stock?More than 0 units: back in stock. Otherwise still out (or the product wasn't found).
  10. Step 10Back in stockThis row gets an email after the wording is approved.
  11. Step 11Still out of stockChecked again next run.
  12. Step 12Count the waitlistIn code: which rows are back in stock, still out, or already notified.
  13. Step 13Write the back-in-stock emailAI writes the subject and the opening and closing lines once for this run, in your voice. The product name and link are filled in from each row in code.
  14. Step 14Anything back in stock?In code: at least one waitlist row is back in stock.
  15. Step 15Send, and review first?Nothing back in stock: the run ends. With review on (the default) the wording waits for approval; with review off it goes to the checks.
  16. Step 16Nothing back in stockNo waiting row's product is in stock yet.
  17. Step 17Approve the back-in-stock emailThe subject, opening and closing wait in Reviews with the list of rows to email. Edit, approve to send, or reject to send nothing this run.
  18. Step 18Check the wordingIn code: subject, opening and closing are there and have no leftover placeholders.
  19. Step 19Passed the checks?Passed: the emails go out. Otherwise nothing is sent and the rows stay waiting.
  20. Step 20Held: nothing sentThe wording was blank or had a placeholder.
  21. Step 21Each waitlist rowGoes through this run's waitlist rows again and emails the ones back in stock (up to 100).
  22. Step 22Back in stock?Only rows found back in stock in this run are emailed.
  23. Step 23No emailStill out of stock, or already notified.
  24. Step 24Emailed before?Remembers who was emailed about which product (kept a year), so each person gets one email per product even if the sheet isn't marked.
  25. Step 25New?Emailed about this product before: skipped.
  26. Step 26Already emailedThis person was emailed about this product before.
  27. Step 27Check the rowIn code: one valid email address and a product link.
  28. Step 28Valid?A row without a valid email or a product link isn't emailed.
  29. Step 29Not emailed: check the rowThe Email or Link cell needs fixing.
  30. Step 30Email themSends the approved wording from your Gmail with their first name, the product's name and its link.
  31. Step 31Mark the row NotifiedWrites the date and time into the row's Notified cell, so it's never emailed again.
  32. Step 32Remember the emailMarks this person and product as emailed (kept a year).
  33. Step 33Count the emailsIn code, not AI: who was emailed, skipped or held, and any send that failed.
  34. Step 34DoneThe run history keeps the counts; the sheet shows who was notified.

Example run

What goes in, and what comes out.

Example with fictional data

Comes in

Waitlist sheet: 3 rows for the linen apron, 1 for the oak board, 1 row already marked Notified. Shopify shows 12 aprons and 0 boards.

The agent produces

The apron rows are back in stock, the board is still out and the notified row is skipped. After approval, 3 emails go out, the rows are marked Notified, and the run counts 3 emailed, 1 still out, 1 already notified.

What you need

Everything it takes to run it.

About 20 minutes from purchase to live. A checklist above the canvas takes you through each step.

Plan

Included in Enterprise; on other paid plans it's $79 once. Agents run live on paid plans, from Basic ($39/mo).

Your AI key

Connect any of 15 AI providers on your own key. Your provider bills usage directly, at cost; we add no markup.

Apps

Checklist

  • A paid plan (agents run live on paid plans).
  • An AI provider key (Settings → AI Providers).
  • Google Sheets, Shopify and Gmail, connected in Settings → Integrations.
  • A waitlist tab with the columns Email | Name | Product | Link | Notified, with the product title as in Shopify and the product page link.

Setup, about 20 minutes

  1. Connect your AI provider. The AI steps run on your own key (OpenAI, Anthropic, Google and more). Add one in Settings → AI Providers.
  2. Connect Google Sheets. Connect the Google account that can open your waitlist (Settings → Integrations → Google Sheets).
  3. Connect Shopify. Connect your store with a custom app that has read_products (Settings → Integrations → Shopify).
  4. Connect Gmail. Connect the Gmail account the emails go out from (Settings → Integrations → Gmail).
  5. Pick the waitlist. Open “Read the waitlist” and pick the account, spreadsheet and tab (columns Email | Name | Product | Link | Notified).
  6. Pick your store. Open “Find the product in Shopify” and pick your store.
  7. Describe your store. Open “Write the back-in-stock email” and replace the placeholder with your rules and review switch.
  8. Gmail and marking rows. Open “Email them” and pick the Gmail account; open “Mark the row Notified” and pick the same sheet and the Notified column letter.
  9. Test it with Dry Run. Press Dry Run: the agent runs on sample data with no messages sent and nothing written to your apps.
  10. Switch the trigger on. Open the trigger, set your time zone and switch the schedule on. It runs at 9:00 and 15:00.

Is it a fit?

Who it's for, and what it won't do.

Built for

  • Shopify stores with products that sell out
  • Makers and small brands with limited batches
  • Shops collecting waitlist signups in a form or sheet

What it doesn't do

  • Shopify only; it finds products by title, so the Product column must match the product's title in Shopify.
  • Stock is counted from Shopify's inventory quantities; products that don't track inventory always read as out of stock.
  • It doesn't collect waitlist signups: your form or store app fills the sheet.
  • At most 100 rows a run, and Gmail's daily sending limits apply.

We list the limits up front so you can decide before you buy.

Price

$79 one-time

Per workspace. It never renews.

Available now
  • Included at no extra cost on Enterprise.
  • Buying and running it live need a paid plan, from Basic ($39/mo).
  • Dry Run costs nothing: simulated AI and app calls, nothing sent.
  • AI usage is billed by your own provider, at cost. No AI credits to buy from us.
Get this agent See how it works

One-time agent purchases aren't covered by the 30-day money-back guarantee. Refund policy

FAQ

Questions about Back-in-Stock Notifier.

How does it know a product is back?

It finds the product in Shopify by the title in your sheet and adds up the inventory of its variants in code. More than zero means back in stock.

Can someone be emailed twice?

No: each row is marked Notified after the email, and the agent also remembers every person and product for a year.

Which apps do I need?

Google Sheets for the waitlist, Shopify for stock and Gmail to send, plus your own AI provider key. Gmail's daily sending limits apply.

Is it worth it?

It's a one-time purchase that never renews, and every waitlist signup becomes a timely email. Running it live needs a paid plan; Dry Run is free.

Can someone get the email twice?

No: the row is marked Notified after the email, and the agent also remembers each person and product for a year.

Why Gmail?

People on a waitlist asked to hear from you, so a personal email from your own address fits. Gmail's daily limits apply (about 500 a day, 2,000 on Google Workspace); the agent sends at most 100 a run.

Is this a subscription?

No. Back-in-Stock Notifier is a one-time purchase of $79 per workspace and never renews. The Enterprise plan includes it at no extra cost. Running it live needs a paid plan (from Basic ($39/mo)), and your AI provider bills you directly for usage.

Can I test it before it touches real data?

Yes. Once it's set up in your workspace, Dry Run plays every step on sample data with simulated AI and app calls: nothing is sent and nothing in your apps changes. Switch the trigger on only when you're happy.

Put Back-in-Stock Notifier to work.

Free account, no credit card. Your Agents page opens with Back-in-Stock Notifier ready to buy and set up, then Dry Run it before it goes live.

Get this agent See how it works