Excel Stock Replenishment Automation with Google Drive & OpenAI

Automatically calculate Excel stock replenishment from Google Drive using OpenAI

This n8n workflow watches a Google Drive folder for newly uploaded XLSX inventory reports, then uses OpenAI (GPT-4.1 mini) to calculate per-SKU replenishment needs and write the results back into your spreadsheet—before moving the processed file to an output folder.

What this workflow does

• Triggers on new files: When a new .xlsx file is created in a specified Google Drive folder, the workflow starts.
• Downloads and parses rows: The file is downloaded from Google Drive, extracted as rows, and split into row batches for efficient processing.
• Generates reorder guidance with OpenAI: For each batch, the workflow sends a compact JSON prompt to OpenAI GPT-4.1 mini, including sales, purchase, and stock metrics per SKU. OpenAI returns:
  • reorder quantity
  • a one-sentence Turkish reason per row
• Writes results back to the spreadsheet: The workflow maps results to the original rows and adds:
  • Column AB: need
  • Column AC: reason
• Rebuilds, updates, and moves: After all batches are processed, rows are reassembled in the original order, converted back to XLSX, the original Google Drive file is updated, and then it is moved to a designated output folder.

Use cases

• SaaS operators automatically enriching incoming inventory XLSX reports with reorder quantities.
• Automation engineers streamlining stock replenishment calculations without manual spreadsheet work.
• Teams processing frequent Excel inventory exports stored in Google Drive, with clear per-item reasoning (Turkish) alongside recommended quantities.

Technical details

• Integrations / credentials: Google Drive (OAuth2) and OpenAI API.
• OpenAI model: gpt-4.1-mini in the “Message a model” step.
• Workflow logic: extract XLSX rows, split into batches, send JSON prompts per batch, merge results, then convert back to XLSX.
• Setup requirement: Ensure your XLSX column headers match the fields expected by the workflow prompt.