Agentic standards, measured
Most writing about these standards explains what they are. These pages count how many sites actually implement them, and separate the sites that carry the code from the sites where it works. Every figure is dated and carries the population it was measured against.
WebMCP
WebMCP lets a page register tools an agent can call, in the page itself, rather than at a separate endpoint. The site declares what can be done and the agent calls it directly — the page becomes the API.
580 of 6472026-08-31
Markdown negotiation
A site that answers Accept: text/markdown with actual markdown hands an agent the content without the navigation, scripts and layout it would otherwise have to strip. The same URL, a cleaner representation.
10,877 of 14,3512026-08-23
Model Context Protocol
MCP is the protocol an agent uses to discover and call a server's tools. On the open web a site advertises one through a server card, and an agent connects to the endpoint the card names.
6,026 of 8,8172026-08-23
llms.txt
A file at /llms.txt listing the pages a site considers worth reading, in markdown, as a curated entry point rather than a crawl.
11,154 of 14,3512026-08-23
API catalog
A machine-readable catalogue of a site's APIs at a well-known location, so an agent can find the interface without reading the documentation. Usually an OpenAPI document, discovered through /.well-known/api-catalog.
5,399 of 14,3512026-08-23
Observed
Link headers
Capability and relation links delivered in the HTTP response header rather than the document body. We serve them.
no countARD (Agentic Resource Discovery)
A manifest at a well-known path listing the agentic resources a site offers. We serve one, at /.well-known/ard.json.
no countUCP (Universal Commerce Protocol)
A discovery layer that advertises a site's commerce endpoints to an agent. We do not serve it.
no countWeb Bot Auth
Signed HTTP requests that let a site verify which bot is calling it. We do not serve it.
no countx402
Agent-payable HTTP: a 402 response an agent can settle to obtain the resource. We do not serve it.
no countACP · MPP · AP2
Commerce protocols for agent-initiated purchase and payment. We do not serve them.
no countDNS-AID
Agent discovery at the DNS layer, published as records rather than over HTTP. We do not serve it.
no count