Step 2: Connect Google Sheets for Inventory and Logging

Configure the spreadsheet lookups for stock levels and the log append for order outcomes.

1. Open Retrieve Stock Levels and connect the sheet that holds SKU inventory.
2. Credential Required: Connect your googleSheetsOAuth2Api credentials.
3. Set Operation to lookup, Range to Inventories!A:B, and Lookup Column to sku.
4. Set Lookup Value to ={{$json["sku"]}} and Sheet ID to your spreadsheet ID (replace [YOUR_ID]).
5. Open Append Log Sheet and set Operation to append with Range OrderLogs!A:E and your Sheet ID.
6. Credential Required: Connect your googleSheetsOAuth2Api credentials.

Step 3: Set Up Order Parsing and Preparation Functions

These function nodes validate the incoming payload and normalize order data for stock checks and invoicing.

1. Open Validate Order Payload and keep the validation logic that throws an error for missing id, customer, or items.
2. Open Prepare Order Details to map customer data, items, and totals into a consistent structure.
3. Open Extract Item Quantities to emit per-item records with sku and qty.
4. Note that Extract Item Quantities outputs to both Retrieve Stock Levels and Combine Item Stock in parallel.

Step 4: Configure Stock Merge and Availability Logic

Combine ordered items with stock levels and check if the order can be fulfilled.

1. In Combine Item Stock, set Mode to combine and Fields to Match to sku.
2. In Stock Availability Check, set the boolean condition to compare quantities and stock using ={{ $items().every(item => item.json.qty <= item.json.stock) }} against ={{ true }}.
3. Confirm that Combine Item Stock feeds into Stock Availability Check for final routing.

Step 5: Configure Success and Shortage Alerts

Send Slack notifications based on whether stock is sufficient or not.

1. Open Slack Success Alert and set the Text to ={{ '✅ Order ' + $json.orderId + 'Invoiced. \nInvoice: ' + $json.invoiceId + ', \nAmount: $' + $json.amount + ', \nCustomer: ' + $json.customer + ', \nDate: ' + $json.date}}.
2. Set Channel to your Slack channel ID (replace [YOUR_ID]), and use Authentication oAuth2.
3. Credential Required: Connect your slackOAuth2Api credentials.
4. Open Slack Shortage Alert and set Text to ={{'⚠️ Order '}} {{ $('Prepare Order Details').item.json.id }} {{'is not available for order due to lack of stock.'}} \n{{'\n SKU: '}} {{ $json.sku }}\n{{'\n Request quantity: '}} {{ $json.qty }}\n{{'\n Stock quantity: '}} {{ $json.stock }}.
5. Set Channel to your Slack channel ID (replace [YOUR_ID]) and ensure Authentication is oAuth2.
6. Credential Required: Connect your slackOAuth2Api credentials.

Step 6: Build Invoice and Logging Records

Create invoice data for successful orders and log outcomes for both success and shortage branches.

1. Open Generate Invoice Record and keep the invoice construction that uses Prepare Order Details and Extract Item Quantities fields.
2. Verify Generate Invoice Record outputs to Slack Success Alert.
3. Open Build Success Log and confirm it sets status to Success.
4. Open Build Shortage Log and confirm it sets status to Out of Stock.
5. Ensure both Build Success Log and Build Shortage Log connect to Append Log Sheet.

Step 7: Test & Activate Your Workflow

Run a manual test with a sample payload to confirm stock checks, alerts, and logging are working.

1. Click Execute Workflow and send a test POST request to the Incoming Order Hook URL with a valid order payload.
2. Successful execution should: pass Validate Order Payload, populate Prepare Order Details, and complete stock lookup/merge before Stock Availability Check.
3. If stock is available, verify a message in Slack Success Alert and a new row appended by Append Log Sheet.
4. If stock is insufficient, verify a message in Slack Shortage Alert and a log entry from Build Shortage Log appended to Append Log Sheet.
5. Once verified, toggle the workflow to Active for production use.