The AI Domain Data Standard (AIDD) is a simple, open, & vendor-neutral way for websites to publish authoritative, machine-readable identity data for AI systems, search engines, and agents. It provides a canonical JSON profile via /.well-known/ plus an optional DNS txt record fallback. AIDD reduces AI hallucinations about websites, improves domain understanding. Plugins available for WordPress(pending), Jekyll, Next.js, and CI validation. More integrations on the way.