Monitor Product Prices & Stock with n8n, Sheets, OpenAI, Slack

Never miss a product price drop or stock change—automatically

This n8n workflow checks your monitored product URLs every 6 hours, extracts the latest price and availability from fully rendered pages, and sends Slack alerts only when something actually changes—then updates your Google Sheets watchlist with the new values.

What this workflow does

• Runs on a schedule: Executes every 6 hours to keep your data current.
• Reads a watchlist from Google Sheets: Loads product URLs and the last known price/availability values from a dedicated tab, then processes items one by one.
• Captures fully rendered HTML: Uses Snapshot Site to fetch each product page as rendered HTML. If Snapshot Site returns an API error, the workflow posts a failure message to Slack.
• Extracts price and availability with OpenAI: Cleans the HTML and uses OpenAI (LangChain Information Extractor) to extract current price, currency, availability, title, and SKU.
• Detects changes vs. last recorded values: Compares extracted price and stock status against the previously saved values to classify results as a change, unchanged, or initial baseline.
• Notifies only when it matters: Sends a Slack message only when a real price or stock change is detected.
• Updates Google Sheets: Appends or updates the matching watchlist row (matched by URL) with the latest price, availability, currency, check timestamp, and change type.

Use cases

• Monitor competitor listings and get instant alerts in Slack when prices drop or items go in/out of stock.
• Track inventory visibility for multiple SKUs with a Google Sheets-backed watchlist.
• Use as a lightweight “price & stock monitoring” pipeline for SaaS operations or e-commerce teams.

Technical details

• Nodes/integrations: n8n community node n8n-nodes-snapshot-site, Google Sheets, OpenAI (LangChain Information Extractor), and Slack.
• Supporting logic: scheduling plus flow controls using nodes such as if, set, code, no op, and documentation via sticky note.

Setup (quick)

• Install n8n-nodes-snapshot-site and add a Snapshot Site API credential.
• Add Google Sheets OAuth credentials and update the watchlist Spreadsheet ID/URL.
• Add OpenAI API credentials for the Information Extractor model.