Captcha

Captcha is not only about visual tests but for confirming is a user human or not.

Are you just a member of a chat and not a chat administrator?

Read the captcha description for chat members: https://docs.fullyst.com/features/captcha/captcha-for-chat-members

Captcha configuration

For the current moment, you can configure a captcha with /settings command in DM with @FullystBot

Button

Button captcha in action (the user joined the chat but ignored the first captcha)

This type of captcha is simple and easy to solve, but some spam bots can bypass this captcha. We recommend it to use this captcha type only with other spam-protection features like AI-antispam, NSFW protection, and moderation tools like /report command

Math

Math captcha in action (the user joined the chat but ignored the first captcha)

This type of captcha provides an additional level of security and can protect your chat from 98% of spam bots.

With math type, all new users must solve a simple math problem (for example 28+7, 3+18, 45-8) with five options with only one correct. The user has only a limited number of attempts and each incorrect choice will regenerate the math problem and solutions, so this type of captcha is almost impossible to bypass by spambots. After reaching the maximum number of attempts, the user will be banned and you can unban them only with the /unban command or in chat's settings.