Captcha can be enabled for this home server. This file explains how to do that. The captcha mechanism used is Google's ReCaptcha. This requires API keys from Google. Getting keys ------------ Requires a public/private key pair from: https://developers.google.com/recaptcha/ Must be a reCAPTCHA v2 key using the "I'm not a robot" Checkbox option Setting ReCaptcha Keys ---------------------- The keys are a config option on the home server config. If they are not visible, you can generate them via --generate-config. Set the following value:: recaptcha_public_key: YOUR_PUBLIC_KEY recaptcha_private_key: YOUR_PRIVATE_KEY In addition, you MUST enable captchas via:: enable_registration_captcha: true Configuring IP used for auth ---------------------------- The ReCaptcha API requires that the IP address of the user who solved the captcha is sent. If the client is connecting through a proxy or load balancer, it may be required to use the X-Forwarded-For (XFF) header instead of the origin IP address. This can be configured using the x_forwarded directive in the listeners section of the homeserver.yaml configuration file.