n8n Workflow: Construction Stock Monitor and Low Inventory Alerts

This n8n workflow provides a robust solution for monitoring construction stock levels from a Google Sheet and sending email alerts when inventory falls below a specified threshold. It automates the process of regularly checking stock and notifying relevant personnel, ensuring timely replenishment and preventing project delays due to material shortages.

What it does

This workflow performs the following key actions:

1. Schedules Checks: Triggers on a predefined schedule (e.g., daily, hourly) to initiate the stock monitoring process.
2. Reads Google Sheet Data: Connects to a specified Google Sheet to retrieve the latest inventory data for construction materials.
3. Processes Stock Data: Uses a Code node to analyze the retrieved data, identify items with low stock, and determine if an alert is needed.
4. Sends Low Inventory Alerts: If any item's stock falls below a configurable threshold, an email alert is sent to a designated recipient with details of the low-inventory items.

Prerequisites/Requirements

To use this workflow, you will need:

• n8n Instance: A running instance of n8n.
• Google Sheets Account: A Google account with access to the Google Sheet containing your construction stock data.
  • The Google Sheet should have columns for item names and their current stock levels.
• Email Service (SMTP): An SMTP server configured in n8n to send email alerts. This could be a custom SMTP setup or a service like Gmail, SendGrid, etc.

Setup/Usage

1. Import the Workflow:
   • Download the provided JSON file.
   • In your n8n instance, click on "Workflows" in the left sidebar.
   • Click "New" and then "Import from JSON".
   • Paste the JSON content or upload the file.
2. Configure Credentials:
   • Google Sheets:
     • Locate the "Google Sheets" node.
     • Click on "Credentials" and select or create a new "Google Sheets API" credential.
     • Follow the authentication steps to grant n8n access to your Google Sheets.
   • Send Email:
     • Locate the "Send Email" node.
     • Click on "Credentials" and select or create a new "SMTP" credential.
     • Enter your SMTP server details (host, port, user, password, secure option).
3. Customize Workflow Nodes:
   • Cron Node (ID: 7):
     • Adjust the "Trigger Interval" to your desired schedule for checking stock (e.g., every 1 hour, once a day).
   • Google Sheets Node (ID: 18):
     • Enter the "Spreadsheet ID" of your construction stock Google Sheet.
     • Specify the "Sheet Name" where the stock data is located.
     • Ensure the "Operation" is set to "Read" and "Resource" to "Rows".
   • Code Node (ID: 834):
     • This node contains the logic for checking stock levels. You will need to modify the JavaScript code within this node:
       • Column Names: Update the code to match the exact column names in your Google Sheet for item names and stock quantities.
       • Low Stock Threshold: Adjust the lowStockThreshold variable to define what constitutes "low inventory" for your items.
       • Output Structure: Modify the output if you need different data for your email alerts.
   • Send Email Node (ID: 11):
     • To: Enter the email address(es) of the recipient(s) for low inventory alerts.
     • From: Configure the sender email address.
     • Subject: Customize the email subject line (e.g., "Low Construction Stock Alert").
     • Body: Customize the email body to include relevant details from the Code node's output (e.g., list of low stock items, their current quantities). You can use expressions like {{ $json.itemName }} to dynamically insert data.
4. Activate the Workflow:
   • Once all configurations are complete, save the workflow and activate it by toggling the "Active" switch in the top right corner of the workflow editor.

The workflow will now run automatically on your defined schedule, monitoring your construction stock and sending alerts as needed.