A free n8n workflow for Shopify low‑stock alerts (and 4 gotchas)

Description and use

A new n8n automation recipe for Shopify sends Slack alerts about low stock, checking all variants every 4 hours and avoiding duplicate messages.

Problem

Small Shopify stores need early low‑stock alerts, but Shopify only notifies after a sale attempt.

Outcome

The workflow runs every 4 hours, fetches all variants, filters low‑stock items, and sends a single Slack message only when new low‑stock items appear, avoiding duplicate alerts and gift‑card warnings.

Workflow

• Every 4 hours trigger starts the workflow
• Manual trigger allows on‑demand execution
• Config node sets shop URL, API version, threshold, and Slack webhook
• Get access token node exchanges client ID and secret for a 24‑hour Admin API token
• Fetch all variants node calls productVariants in GraphQL and pages until hasNextPage is false
• Find changes node filters active, tracked variants at or below threshold and compares with last run
• Send to Slack node posts one message only when changes are detected

Evidence

I ran it on n8n 2.44.5 against a mock of the Shopify Admin GraphQL API

Source

Every 4 hours (or when you click Execute workflow) it starts.

Source

Get access token swaps your app's client ID and secret for a 24‑hour Admin API token.

Source

Fetch all variants calls productVariants in GraphQL and keeps paging until hasNextPage is false.

Source