LINE Fridge Inventory & Expiry Alerts with n8n, Sheets, Gemini

Register fridge items in LINE—then get AI meal ideas for what expires soon

This n8n workflow lets users snap a food/package image in LINE, automatically extracts the item details with Google Gemini, saves them to Google Sheets, and sends a daily LINE notification with short Japanese meal suggestions for items expiring within the next three days.

What this workflow does

• Receives LINE webhook events: When a user sends a message containing a food package image, n8n handles the incoming POST webhook from the LINE Messaging API.
• Downloads the image from LINE: The workflow retrieves the image content using the LINE endpoints configured via HTTP Header Auth.
• Extracts inventory details with Google Gemini: The image is sent to Google Gemini to extract a fixed text set of fields, including food name, expiration date, storage location, and notes.
• Saves to Google Sheets inventory: The extracted details are appended to a Google Sheets table with In Stock status, a registration timestamp, and the originating LINE user ID.
• Confirms registration in LINE: The workflow replies back in LINE, confirming the registration and echoing the stored item details.
• Runs daily expiry checks (09:00): Every day at 9:00, it reads the sheet, filters In Stock items expiring between today and the next three days, aggregates the results, and uses Google Gemini to generate short Japanese meal suggestions.
• Sends push notifications in LINE: The suggestions are delivered via a LINE push notification.

Use cases

• Personal fridge management: keep track of what you have without manual entry.
• Shared household inventory: notify family members in LINE when food is nearing expiry.
• SaaS operators and automation engineers: demonstrate AI-assisted inventory + reminders using n8n, Sheets, and Gemini.

Technical details

• n8n nodes/workflow components: webhook, http request, google sheets, filter, aggregate, sticky note.
• Integrations: LINE Messaging API (reply + push endpoints), Google Gemini, and Google Sheets (OAuth2).
• Core scheduling: daily execution at 09:00 to evaluate expirations and trigger notifications.