Track WooCommerce inventory and send reorder alerts via Gmail and Slack

Description

WooCommerce Inventory Reorder Automation with n8n, Gmail & Slack Alerts

Automatically track product sales and inventory levels in WooCommerce and trigger reorder notifications when stock runs low or sales spike.

This n8n workflow runs daily, analyzes all WooCommerce orders to calculate SKU-wise sales, compares them with current product stock, calculates an optimal reorder quantity and sends automated alerts via Email (Gmail) and Slack when a product meets reorder conditions.

Quick Implementation Steps (Get Started Fast)

Import the workflow JSON into your n8n instance.
Connect WooCommerce, Gmail and Slack credentials.
Set the Schedule Trigger to run daily.
Update email recipients and Slack channel.
Activate the workflow.

What It Does

This workflow automates inventory monitoring and reorder decision-making for WooCommerce stores. On a daily schedule, it fetches all orders from WooCommerce and calculates how many units of each SKU were sold. This gives you a clear picture of recent sales velocity without manual reporting.

The workflow then retrieves live product inventory data from WooCommerce, including current stock levels and low-stock thresholds. Sales data and product data are merged using SKU matching and evaluated using logical conditions to determine whether a product should be reordered.

When a product meets the reorder criteria, the workflow calculates an optimal reorder quantity using average daily sales, supplier lead time and safety stock logic. It then automatically notifies the purchasing team via email and Slack, ensuring no critical stock replenishment is missed.

Who’s It For

This workflow is ideal for:

WooCommerce store owners
Inventory and supply chain managers
E-commerce operations teams
Businesses looking to reduce stockouts
Teams that want proactive, automated purchase alerts

Requirements to Use This Workflow

To use this workflow, you will need:

An active n8n instance
A WooCommerce store with:
Products using SKUs
Stock management enabled
WooCommerce API credentials with access to:
Orders
Products
A Gmail account connected to n8n (OAuth2)
A Slack workspace with bot permissions
Basic understanding of n8n nodes and credentials

How It Works & How To Set Up

Step-by-Step Workflow Logic

Schedule Trigger (Daily)
The workflow runs automatically once per day.
Fetch All WooCommerce Orders
Retrieves all available orders from WooCommerce.
No status or date filtering is applied.
Calculate Sales per SKU
A JavaScript Code node loops through order line items.
Quantities sold are aggregated per SKU.
Fetch All WooCommerce Products
Retrieves product inventory data including:
Stock quantity
Low stock threshold
Product name
Merge Sales & Product Data
Sales data and product inventory data are merged using SKU matching.
Reorder Eligibility Filter
A product qualifies if either condition is met:
Current stock ≤ low-stock threshold
OR recent sales quantity ≥ 1.5× low-stock threshold
Reorder Quantity Calculation
Uses:
Average daily sales
Fixed lead time (7 days)
Safety stock (5 units)
Calculates recommended reorder quantity.
Email Notification
Sends a formatted HTML email with reorder details.
Slack Notification
Sends a real-time alert to a specified Slack channel.

How To Customize Nodes

You can easily adapt this workflow to your business needs:

Schedule Trigger**
Change execution frequency (daily, weekly, etc.).
Sales Calculation Code**
Modify logic to:
Ignore certain SKUs
Add time-based filtering
Apply weighted averages
Filter Conditions**
Adjust reorder rules:
Change sales multiplier
Use AND logic instead of OR
Reorder Formula**
Update lead time or safety stock values.
Integrate supplier-specific rules.
Email & Slack Nodes**
Replace recipients and channels.
Customize message formatting or branding.

Add-ons (Extend the Workflow)

You can enhance this workflow with:

Automatic purchase order creation in ERP systems
Google Sheets logging for reorder history
Vendor-specific reorder logic
Forecast-based inventory planning
Approval workflows before notifications
Webhook integration with procurement tools

Use Case Examples

Primary use cases include:

Preventing stockouts in fast-moving WooCommerce stores
Automating daily inventory monitoring
Supporting purchasing teams with data-driven reorder alerts
Replacing manual stock checks and spreadsheets
Improving response time to sudden sales spikes

There are many more variations of this workflow that can be adapted to different industries and store sizes.

Troubleshooting Guide

| Issue | Possible Cause | Solution |
|-----|---------------|----------|
| No emails sent | Gmail credentials not connected | Reconnect Gmail OAuth2 |
| No Slack alerts | Wrong channel ID or permissions | Update channel and Slack app scopes |
| Reorder triggered too often | Filter logic too sensitive | Adjust threshold values |
| Missing sales data | Products without SKUs | Ensure all products have SKUs |
| Workflow fails | WooCommerce API limits | Reduce frequency or paginate data |

Need Help?

Need assistance setting up this workflow or customizing it for your business?

Our n8n workflow development team at WeblineIndia specializes in building advanced n8n automations, WooCommerce integrations and end-to-end business process workflows.

Whether you need enhancements, add-ons or a completely custom automation solution, our experts are here to help you streamline operations and scale efficiently.

Contact WeblineIndia to get started with smarter automation today.