Manage subscription renewals with Supabase, Gmail, and a payment API

Quick overview

This workflow runs daily to check subscription records in Supabase, email renewal reminders via Gmail for subscriptions expiring within three days, post payment details to an HTTP API, and then update the subscription and send either a renewal confirmation or a payment failure email.

How it works

1. Runs every day at 09:00 using a schedule trigger.
2. Gets the current date/time and fetches all records from the Supabase subscriptions table.
3. Filters to subscriptions with status set to active and whose end_date falls between now and the next three days.
4. Sends a renewal reminder email to the subscription owner using Gmail.
5. Sends the subscription and payment identifiers to an external HTTP endpoint for payment processing and flags the response as successful when an id is present.
6. If the payment response indicates success, updates the Supabase subscription record with active status, a new start/end date, and last_payment_date, then emails a renewal confirmation via Gmail.
7. If the payment response indicates failure, emails the customer a payment failure notice via Gmail.

Setup

1. Add a Supabase credential and ensure the subscriptions table exists with fields used by the workflow (for example subscription_id, user_id, email, status, start_date, end_date, last_payment_date, and any payment ID fields).
2. Add a Gmail credential that has permission to send emails from your account.
3. Replace the HTTP Request URL with your real payment processing endpoint and adjust the JSON payload fields to match your API contract.
4. Confirm the schedule trigger time (09:00) and adjust it to your desired timezone and run time.

Additional info

How To Customize Nodes

You can easily customize this workflow based on your business requirements:

• Schedule Trigger: Change execution frequency.
• Subscription Expiry Logic: Adjust the expiry window from 3 days to any custom duration.
• Payment API: Replace the placeholder API with Stripe, PayPal, Razorpay, or custom gateways.
• Email Templates: Customize reminder, success, and failure email designs.
• Renewal Duration: Change renewal logic from monthly to yearly subscriptions.
• Supabase Schema: Add custom fields like plan type, billing cycle, or payment status.

Add-ons (Extend the Workflow)

You can enhance this workflow with:

• Stripe or PayPal direct integration
• SMS notifications using Twilio
• WhatsApp renewal reminders
• Subscription analytics dashboard
• Google Sheets logging
• Failed payment retry mechanism
• Auto-cancel expired subscriptions
• Webhook integrations for CRM systems

Use Case Examples

Primary use cases include:

1. SaaS subscription renewal automation
2. Membership expiration management
3. Automated recurring billing reminders
4. Subscription lifecycle tracking
5. Reducing churn through proactive notifications
6. Automating payment follow-ups

Troubleshooting Guide

Issue	Possible Cause	Solution
No emails sent	Gmail credentials disconnected	Reconnect Gmail OAuth2
Payment API fails	Invalid API endpoint or payload	Verify API URL and request body
Subscriptions not updating	Supabase permissions issue	Check API roles and table access
Workflow not triggering	Schedule disabled	Activate workflow
Incorrect expiry filtering	Date format mismatch	Ensure timestamps use ISO format

Need Help?

WeblineIndia specializes in building advanced n8n automations, WooCommerce integrations and end-to-end business process workflows. If you need enhancements, add-ons or a completely custom automation solution, our n8n experts at WeblineIndia are happy to help.

👉 Contact WeblineIndia to get started with smarter automation today.