Since version 1.5.3 Hatta now has build-in support for ReCAPTCHA. To enable it, you need to add two configuration variables to your Config:

• recaptcha_public_key
• recaptcha_private_key

You'll also need to install the recaptcha-client library.

Note that at the moment only editing text pages and uploading files requires CAPTCHA – reverting changes to pages doesn't. That's because the latter is not targetted by spammers, possibly because it doesn't contain a <textarea> tag.