Send SSL certificate expiry alerts for your domains to Telegram

Quick overview

This workflow runs daily to check the SSL certificate expiry status of a configured list of domains using the NetworkCalc certificate API, then sends a single consolidated alert message to a Telegram chat when certificates are expiring, expired, mismatched, or cannot be checked.

How it works

1. Runs every day at 08:00 on a schedule.
2. Reads your configured domain list, cleans and deduplicates it, and limits processing to 50 valid domains.
3. Queries the NetworkCalc public certificate API for each domain to retrieve SSL certificate details.
4. Evaluates each result to detect expiry thresholds, already-expired certificates, hostname mismatches, and repeated check failures, while tracking previous alert state to avoid duplicate notifications.
5. Builds one prioritized Telegram message containing only the relevant alerts (or a full report when enabled).
6. Sends the formatted alert/report to your specified Telegram chat.

Setup

1. Create a Telegram bot with BotFather and add the Telegram credential (bot token) to the Telegram node.
2. Set the target Telegram chat ID in the workflow settings value for telegram_chat_id.
3. Update domains with your comma/whitespace-separated list of public domain names and adjust alert_days_before (and optionally report_all) to match your alerting needs.