Imagine setting up a Telegram bot for order processing or lead capture. You deploy a public script named webhook.php , register its public URL with Telegram, and handle incoming user interaction. Without authentication and idempotency, this simple endpoint creates major production vulnerabilities. Anyone who discovers or guesses your public endpoint URL can send forged HTTP POST requests containing arbitrary JSON payloads, pretending to be Telegram servers or impersonating real users placing orders.

In addition, network hiccups, database latency, or script execution delays often cause your PHP script to take longer than Telegram's internal timeout threshold (around 5 seconds) to respond. When Telegram does not receive an HTTP 200 OK status code within that window, it terminates the connection and retries sending the exact same payload over and over.…