This piece connects signals from the past year: Web Bot Auth signing, BotBase registration, Content Signals purpose declaration, and Cloudflare's Sept 15 default block on AI crawlers for ad-containing pages. The four-layer stack sounds complete, but the top three are voluntary—OpenAI's main crawler GPTBot still hasn't adopted signing, Googlebot hasn't either, and there's no public evidence Anthropic's crawlers have. Only the bottom default layer has teeth, and Cloudflare serves 24.3% of all websites, 84.1% of sites with identifiable reverse proxies. It's effectively making defense decisions on behalf of site owners.
I'd discount the completeness claim. Web Bot Auth has zero formally adopted IETF documents—nine proposals, all individual submissions—yet AWS already defaults to allowing signed agent traffic in production. The format has already forked: Google follows the new spec, OpenAI uses the old string format, and Cloudflare's verification docs list the new dictionary format as a failure case. Build to one vendor's guide and you'll hit interop bugs.
The top Hacker News comment nailed it: still the honors system. What I'm actually watching is Cloudflare's payment pipeline—per-request billing ran in private beta for a year, then shifted to per-referral in July 2026. Identity registration, signature verification, blocking policy all sit with one platform. Site owners just accept the classification output. Same playbook as Google and Yahoo tying DMARC to inbox delivery in February 2024: edge gateway enforcement moves faster than standards bodies.