Captcha

Tip: change one option at a time and verify the result in the group so false positives are easy to spot.

In short

Captcha protects new members and join requests. Choose the simplest challenge that stops the attack without hurting real users.

How it works

A new member joins the chat or submits a join request, depending on the selected mode.
Defendy presents the selected challenge and starts the timer and attempt counter.
A correct answer grants access; timeout or exhausted attempts applies the configured failure action.

Set it up step by step

Open Defendy in Telegram and choose the group you want to configure.
Compare the current values with the defaults explained below.
Change one option at a time; use the least disruptive value that meets your goal.
Check the result in the group after saving.

Every setting explained

Enable captcha

Default: Off.

Turns verification on for new members or join requests.

Captcha mode

Default: In chat.

In-chat challenge or join-request verification.

Captcha type

Default: Button.

Button, math, emoji, question or random. Adaptive (auto) exists in the contract but is deliberately hidden from the current WebApp.

Random type pool

Default: button, math, emoji, question.

Challenge types used in random mode. At least one type must remain enabled; the WebApp blocks turning off the last one.

Timeout

Default: 300 sec.

How long a member has to pass the challenge. The WebApp offers 30, 60, 90, 120, 180 or 300 seconds; the API accepts up to 600 seconds.

Attempts

Default: 1.

How many failed attempts are allowed: 1, 2, 3 or 5.

Fail action

Default: Kick.

Kick, mute or ban when captcha fails.

Fail-action duration

Default: 0 (permanent for ban).

Duration for a temporary mute or restriction. It appears only for an action that supports a duration; zero means permanent where applicable.

Captcha topic

Default: Not set.

Optional forum topic for captcha messages in in-chat mode.

Set captcha topic

Default: Not set.

When group topics are enabled and captcha works in chat, turn off “use global topic” and send /setcaptchatopic inside the target topic.

Practical example

Start with in-chat button captcha, five minutes, one attempt and kick. Join with a second account and test success, timeout and an incorrect answer before enabling it in a large group.

Recommendations

Button captcha is usually best for low-risk groups.
Join-request mode changes the user journey; test it before enabling in a large group.

Troubleshooting

Check that Defendy is still an administrator in the group.
Refresh the settings panel and make sure you are editing the correct group.
If a setting is saved but does not work, check the bot permissions in Telegram.
If you are not sure what happened, open the moderation log.