n8n Workflow: Google Sheets Doc Reminders via OpenAI + Gmail

Automate Google Sheets doc reminders—drafted by OpenAI and sent via Gmail

This n8n workflow automatically checks your Google Sheets “Requests” list every weekday morning, generates reminder emails with OpenAI in your preferred tone, sends them through Gmail, and then updates each row with the latest “Last sent” date and “Reminders” count.

What this workflow does

• Runs on a schedule: triggers every weekday at 8am using an n8n schedule.
• Reads open requests: loads rows from the Google Sheets “Requests” tab where Status = Open.
• Calculates reminder timing: determines how many reminders have already been sent, how many days have passed since the last email, and whether the next message should be a first request, reminder, or final reminder.
• Enforces your policy: if enough time has passed and the reminder limit is not exceeded, it proceeds.
• Generates email content with OpenAI: creates a short email subject and body tailored to the client and document.
• Sends via Gmail: delivers the reminder to the client, using your configured reply-to address.
• Updates Google Sheets: writes today’s date to Last sent and increments Reminders for that row.

Use cases

• Send consistent follow-ups for document requests tracked in Google Sheets—without manual copy/paste.
• Maintain a controlled reminder cadence (days between reminders + max reminders) for client compliance.
• Standardize messaging tone while still personalizing subject/body per Client and Document.

Technical details

• Schedule Trigger (weekdays at 8am)
• Google Sheets (reads/writes “Requests” tab: Status, Last sent, Reminders)
• OpenAI (drafts reminder subject + body)
• Gmail (sends email; uses configured reply-to)
• Logic nodes including if and set (for reminder decisioning and payload setup)
• Sticky Note (workflow documentation)

Setup required: add Google Sheets credentials and spreadsheet ID, connect Gmail credentials and reply-to, and configure an OpenAI credential. Optionally adjust tone, daysBetweenReminders, and maxReminders.