Hi, I'm launching an AI search engine (ex Perplexity like). I don't want to force people to sign up to use it. I want free visitors be able to discover it and use it. However, I've had issues in the past with bots spamming usage, which exploded my costs.

What are the best methdos to prevent those bots, while also having a frictionless UX ? I've heard of Cloudflare. Will that pop for every user or only for those who are trully suspicious ?

Thanks