llms.txt is an emerging specification file placed at your domain root that provides LLMs with structured information about your website — including site description, expertise areas, key pages, author credentials, and preferred citation format. While robots.txt controls crawler access, llms.txt helps AI models understand and properly cite your content.

Add 'User-agent: GPTBot' followed by 'Allow: /' to your robots.txt file. You can also specify 'Disallow' rules for private areas like /admin/ or /account/. Make sure no wildcard rules are inadvertently blocking GPTBot access.

If you want AI platforms to cite your content (recommended for most businesses), allow AI crawlers. Blocking GPTBot prevents ChatGPT citations, blocking PerplexityBot removes you from Perplexity results entirely, and blocking ClaudeBot prevents Claude citations. Only block if you have specific reasons to prevent AI from accessing your content.

The five most important schemas for AI citation optimization are: Organization (brand identity), Article (content metadata and authorship), FAQPage (extractable Q&A pairs), HowTo (structured instructions), and Review (social proof). These help AI models understand and extract citation-worthy information from your pages.

Three methods: validate robots.txt using Google's tester and manual review for AI bot rules, check server logs for GPTBot/PerplexityBot/ClaudeBot activity, and test relevant queries on AI platforms to verify your content appears in responses.