Subscription Renewal Reminder – Telegram & Supabase

This workflow tracks upcoming subscription expiry dates stored in Supabase and automatically sends personalized renewal-reminder messages to each customer via Telegram. It is designed to be triggered by an HTTP Webhook (manually or on a schedule) and ensures that customers are notified a configurable number of days before their subscription lapses.

Community Template Disclaimer
This is a community-contributed n8n workflow template. It is provided “as-is” without official support from n8n GmbH. Always test thoroughly before using in production.

Pre-conditions/Requirements

Prerequisites

• n8n instance (self-hosted or n8n.cloud)
• Supabase project with a subscriptions table
  (id, customer_name, expiration_date, telegram_chat_id, notified)
• A Telegram Bot created via @BotFather
• Outbound HTTPS access from n8n to api.telegram.org and your Supabase project REST endpoint

Required Credentials

• Supabase Service Role Key – Full access for reading/writing the subscriptions table
• Telegram Bot Token – To send messages from your bot
• n8n Webhook URL – Auto-generated when you activate the workflow

(ScrapeGraphAI API Key is not required for this non-scraping workflow.)

Specific Setup Requirements

How it works

This workflow tracks upcoming subscription expiry dates stored in Supabase and automatically sends personalized renewal-reminder messages to each customer via Telegram. It is triggered by an HTTP Webhook (manually or via external scheduler) and ensures that customers are notified a configurable number of days before their subscription lapses.

Key Steps:

• Receive Trigger (Webhook): External call fires the workflow or an internal Cron node can be added.
• Set Static Parameters: The Set node calculates “today + REMINDER_DAYS”.
• Query Supabase: Fetch all subscriptions expiring on or before the calculated date and not yet notified.
• Branch Logic (If node): Check if any subscriptions were returned.
• Loop & Dispatch (Code + Telegram nodes): Iterate over each customer row, compose a message, and send via Telegram.
• Flag as Notified (Supabase Update): Update each processed row to prevent duplicate reminders.
• Respond to Webhook: Return a concise JSON summary for logging or downstream integrations.

Set up steps

Setup Time: 15–20 minutes

1. Create Telegram Bot
   a. Open Telegram and talk to @BotFather → /newbot
   b. Copy the given bot token; paste it into n8n Telegram credentials.

2. Prepare Supabase
   a. Create a table named subscriptions with columns:
   id (uuid), customer_name (text), expiration_date (date),
   telegram_chat_id (text), notified (bool, default false)
   b. Obtain the Service Role Key from Project Settings → API.

3. Import the Workflow
   a. In n8n, click Templates → Import and select “Subscription Renewal Reminder – Telegram & Supabase”.
   b. Replace placeholder credentials in the Supabase and Telegram nodes.

4. Define Environment Variables (Optional but recommended)
   Add SUPABASE_URL, SUPABASE_KEY, TELEGRAM_TOKEN, and REMINDER_DAYS in Settings → Environment Variables for easy maintenance.

5. Activate the Workflow
   Copy the production webhook URL and (optionally) set up a cron job or n8n Cron node to hit it daily.

Node Descriptions

Core Workflow Nodes:

• Webhook – Entry point; triggers the workflow via HTTP request.
• Set (Calculate Target Date) – Defines targetDate = today + REMINDER_DAYS.
• Supabase (Select) – Retrieves expiring subscriptions that haven’t been notified.
• If (Rows > 0?) – Determines whether to continue or exit early.
• Code (For-Each Loop) – Iterates through each returned row to send messages and update status.
• Telegram – Sends a personalized renewal reminder to the customer’s chat.
• Supabase (Update) – Flags the subscription row as notified = true.
• Respond to Webhook – Returns a JSON summary with counts of sent messages.
• Sticky Notes – Inline documentation for maintainers (non-executable).

Data Flow:

1. Webhook → Set → Supabase (Select) → If → Code → Telegram → Supabase (Update) → Respond to Webhook

Customization Examples

Send Slack Notifications Instead of Telegram

// Replace Telegram node with Slack node
const message = `Hi ${item.customer_name}, your subscription expires on ${item.expiration_date}.`;
return [{ text: message, channel: item.slack_channel_id }];

Notify 7 Days & 1 Day Before Expiry

// In Set node
items[0].json.reminderOffsets = [7, 1]; // days
return items;

Data Output Format

The workflow outputs structured JSON data:

{
  "totalSubscriptionsChecked": 42,
  "remindersSent": 13,
  "timestamp": "2024-05-27T09:15:22.000Z"
}

Troubleshooting

Common Issues

1. No messages sent – Check the If node; ensure REMINDER_DAYS is set correctly and the Supabase query returns rows.
2. Telegram error 403 – The user hasn’t started a chat with your bot. Ask the customer to click “Start” in Telegram.

Performance Tips

• Batch database updates instead of row-by-row when dealing with thousands of records.
• Cache Supabase responses if you expect multiple workflows to query the same data within seconds.

Pro Tips:

• Use the Cron node inside n8n instead of external schedulers for a fully self-contained setup.
• Add an Email node after the Telegram node for multi-channel reminders.
• Store template messages in Supabase so non-developers can update wording without editing the workflow.