Set up captcha

Open Settings in your private chat with @defendy_bot, select the group under My groups, then open Captcha.

Configure verification#

1. Enable CAPTCHA.
2. Choose In group to verify newcomers after they join, or Join requests to verify an applicant through a private message.
3. Choose Button, Math, Emoji, Question or Random. Random mode requires at least one selected challenge type.
4. Set the response time and number of attempts.
5. Choose the failure action: Kick, Mute or Ban. For a temporary in-group mute, choose a finite duration after selecting the action: the form resets it to 0, which means no expiry for that mute.
6. Wait for the save to complete. Switches and selectors save when changed.

In group mode applies the selected kick, mute or ban. In Join requests mode, failure declines the application and selecting ban additionally attempts to block the account; selecting mute does not create a temporary in-group mute. Neither CAPTCHA mode applies the selected ban duration in the reviewed implementation, even when the duration field is visible. Do not rely on that ban expiring automatically; a mistaken ban needs to be removed separately.

Forum topics#

The shared group topic is used by default. To choose a separate topic, disable Use global topic, open the target topic in Telegram and send /setcaptchatopic. Return to verify the destination. Topic controls appear only for forum groups in In group mode. Join-request challenges are delivered privately.

Test the result#

Use a test group and a new ordinary member: a Telegram administrator is not a suitable target for restriction tests. Check a correct answer and a timeout; for incorrect answers, choose a challenge with wrong options, such as Math. The simple button has no such choice. For join requests, test approval, rejection and the additional block if you select ban. After reversing a mistaken sanction, verify re-entry and ordinary posting.

The bot needs permission to perform the selected actions. Verify the setup before increasing penalties. See parameters and troubleshooting.