Automated document sync between SharePoint and Google Drive with Supabase

SharePoint → Supabase → Google Drive Sync Workflow Overview This workflow is a multi-system document synchronization pipeline built in n8n, designed to automatically sync and back up files between Microsoft SharePoint, Supabase/Postgres, and Google Drive. It runs on a scheduled trigger, compares SharePoint file metadata against your Supabase table, downloads new or updated files, uploads them to Google Drive, and marks records as completed — keeping your databases and storage systems perfectly in sync. --- Workflow Structure - Data Source: SharePoint REST API for recursive folder and file discovery. - Processing Layer: n8n logic for filtering, comparison, and metadata normalization. - Destination Systems: Supabase/Postgres for metadata, Google Drive for file backup. --- SharePoint Sync Flow (Frontend Flow) - Trigger: Schedule Trigger Runs at fixed intervals (customizable) to start synchronization. - Fetch Files: Microsoft SharePoint HTTP Request Recursively retrieves folders and files using SharePoint’s REST API: /GetFolderByServerRelativeUrl(...)?$expand=Files,Folders,Folders/Files,Folders/Folders/Folders/Files - Filter Files: filter files A Code node that flattens nested folders and filters unwanted file types: - Excludes system or temporary files (~$) - Excludes extensions: .db, .msg, .xlsx, .xlsm, .pptx - Normalize Metadata: normalize last modified date Ensures consistent Lastmodifieddate format for accurate comparison. - Fetch Existing Records: Supabase (Get) Retrieves current entries from n8nmetadata to compare against SharePoint files. - Compare Datasets: Compare Datasets Detects new or modified files based on UniqueId, Lastmodifieddate, and Exists. Routes only changed entries forward for processing. --- File Processing Engine (Backend Flow) - Loop: Loop Over Items2 Iterates through each new or updated file detected. - Build Metadata: get metadata and Set metadata Constructs final metadata fields: - fileid, filetitle, fileurl, filetype, foldername, lastmodifieddate Generates fileUrl using UniqueId and ServerRelativeUrl if missing. - Upsert Metadata: Insert Document Metadata Inserts or updates file records in Supabase/Postgres (n8nmetadata table). Operation: upsert with id as the primary matching key. - Download File: Microsoft SharePoint HTTP Request1 Fetches the binary file directly from SharePoint using its ServerRelativeUrl. - Rename File: rename files Renames each downloaded binary file to its original filetitle before upload. - Upload File: Upload file Uploads the renamed file to Google Drive (My Drive → root folder). - Mark Complete: Postgres Updates the Supabase/Postgres record setting Loading Done = true. - Optional Cleanup: Supabase1 Deletes obsolete or invalid metadata entries when required. --- Integrations Used | Service | Purpose | Credential | |----------|----------|-------------| | Microsoft SharePoint | File retrieval and download | microsoftSharePointOAuth2Api | | Supabase / Postgres | Metadata storage and synchronization | Supabase account 6 ayan | | Google Drive | File backup and redundancy | Google Drive account 6 rn dbt | | n8n Core | Flow control, dataset comparison, batch looping | Native | --- System Prompt Summary > “You are a SharePoint document synchronization workflow. Fetch all files, compare them to database entries, and only process new or modified files. Download files, rename correctly, upload to Google Drive, and mark as completed in Supabase.” Workflow rule summary: > “Maintain data integrity, prevent duplicates, handle retries gracefully, and continue on errors. Skip excluded file types and ensure reliable backups between all connected systems.” --- Key Features - Scheduled automatic sync across SharePoint, Supabase, and Google Drive - Intelligent comparison to detect only new or modified files - Idempotent upsert for consistent metadata updates - Configurable file exclusion filters - Safe rename + upload pipeline for clean backups - Error-tolerant and fully automated operation