📩 Gmail → GPT → Supabase | Task Extractor

This n8n workflow automates the extraction of actionable tasks from unread Gmail messages using OpenAI's GPT API, stores the resulting task metadata in Supabase, and avoids re-processing previously handled emails.

✅ What It Does

1. Triggers on a schedule to check for unread emails in your Gmail inbox.
2. Loops through each email individually using SplitInBatches .
3. Checks Supabase to see if the email has already been processed.
4. If it's a new email:
   • Formats the email content into a structured GPT prompt
   • Calls ChatGPT-4o to extract structured task data
   • Inserts the result into your emails table in Supabase

🧰 Prerequisites

Before using this workflow, you must have:

• An active n8n Cloud or self-hosted instance
• A connected Gmail account with OAuth credentials in n8n
• A Supabase project with an emails table and:

   ALTER TABLE emails ADD CONSTRAINT unique_email_id UNIQUE (email_id);
  

• An OpenAI API key with access to GPT-4o or GPT-3.5-turbo

🔐 Credentials Required

🔁 Environment Variables or Replacements

• Supabase_TaskManagement_URI → eg, https://your-project.supabase.co
• Supabase_TaskManagement_ANON_KEY → Your Supabase anon key

These are used in the HTTP request to Supabase.

⏰ Scheduling / Trigger

• Triggered using a Schedule node
• Default: every X minutes (adjust to your preference)
• Uses a Gmail API filter: unread emails with label = INBOX

🧠 Intended Use Case

Designed for productivity-minded professionals who want to extract, summarize, and store actionable tasks from incoming email — without processing the same email twice or wasting GPT API credits.

This is part of a larger system integrating GPT, calendar scheduling, and optional task platforms (like ClickUp).

📦 Output (Stored in Supabase)

Each processed email includes:

• email_id
• subject
• sender
• received_at
• body (email snippet)
• gpt_summary (structured task)
• requires_deep_work (from GPT logic)
• deleted (initially false)