I’m working on a Telegram bot project and need help with user verification. I want to restrict certain bot features to specific users only, similar to how websites use login systems.
I found information about using deep linking for this purpose, but I’m confused about the implementation steps. Here’s what I understand so far:
Bot Creation - Already done
Webhook Setup - This is where I’m getting lost
Token Generation - Creating random strings for verification
User Linking - Connecting users to chat IDs
From what I can tell, the process involves:
Creating a verification token
Storing it temporarily (like in cache)
Having users click a special bot link with the token
The bot receives a message when they start the conversation
The system matches the token to link the user account with their Telegram chat ID
My main confusion is about the webhook part. I think the Telegram servers send updates to my bot server through a webhook URL when users interact with the bot. Is this correct?
Can someone explain how to properly implement this authentication flow? What happens after the webhook receives the start message with the token?
One thing that tripped me up when implementing similar functionality was handling the deep link format correctly. The telegram bot deep link should look like https://t.me/yourbotname?start=TOKEN_HERE where the token gets passed as a parameter after the start command.
When setting up your webhook endpoint, make sure it can handle the volume of requests if you expect many users. I learned this the hard way when my simple Flask server started timing out during peak usage. Also, be careful with your token storage - I initially used a simple dictionary but that caused issues when the server restarted and all pending tokens were lost.
Regarding webhook implementation, your server needs to be accessible via HTTPS (Telegram requires this) and should respond quickly to avoid timeouts. I found that processing the verification logic asynchronously works better than doing everything synchronously in the webhook handler, especially if you need to make database calls to verify and store the user association.
just a heads up - dont forget to validate the chat_id format before storing it in your db. i made that mistake once and ended up with corrupted data when someone sent weird payload. also telegram sometimes sends duplicate updates so implementing idempotency checks saved me from double-processing tokens.
You’re on the right track with your understanding of the webhook. When users interact with your bot, Telegram does send POST requests to your webhook URL. Your webhook should process these incoming updates and parse the accompanying JSON payload.
Regarding the authentication flow, when your webhook receives the /start command along with the token, you need to extract that token from the message text and check it against your database. If it matches, you can then associate the user’s Telegram chat ID with their account in your system, and remove the token to prevent reuse.
Consider implementing token expiration (typically set for 5-10 minutes) to enhance security. Additionally, ensure that your webhook sends a response with an HTTP 200 status code to confirm receipt; otherwise, Telegram will continue to resend the same update. Based on my experience, sending a confirmation message back to the user upon successful verification can be very helpful, as it provides immediate feedback that the linking process was successful.