Create Secure Human-in-the-Loop Approval Flows with Postgres and Telegram

🔐 Human-in-the-Loop Approval Flow (n8n + Postgres + Telegram)

👥 Who’s it for
Teams that need a manager approval step before a ticket or request can change status. Great for internal ops, IT requests, or any workflow where “a human must sign off.”

⚡ What it does
📨 Manager receives approval/reject link
🔑 Link is signed with HMAC + expiry (secure & tamper-proof)
🗄️ Postgres updates the ticket status
📝 Audit trail records every decision
📲 Telegram notifies both manager and requester
⏰ Expired or invalid links trigger alerts and logs

🛠 Requirements
n8n instance (self-hosted)
Postgres database (with tickets, ticket_audit, workflow_errors)
Telegram bot token
One environment variable set: SECRET_KEY

⚙️ How to set up
Set SECRET_KEY in .env
Create Postgres tables (SQL provided)
Add Telegram + Postgres credentials in n8n
Import the workflow JSON
Test by opening an approval/reject link in your browser

🎨 How to customize
Change who the “manager” is (currently hardcoded in the Code node).
Swap Telegram for Slack or email notifications.
Extend the audit schema to include more metadata (IP, username).