Standards measurements

Each week APIs.io probes the website of every provider in the catalog for the well-known documents that agent and commerce standards define, and publishes what it finds. The counts always carry their denominators, and every week's file is kept, so the series can be compared over time. The data is free to use under CC BY-NC-SA 4.0.

Latest: 2026-10-30

Download: latest JSON · latest CSV

Every week

• 2026-10-30: JSON · CSV

Method

• Who is probed. The first Website listed on each provider's APIs.io profile, which is the company's own site. API and docs subdomains are not probed here.
• What counts as a hit. A document of the right shape, not just a 200: a ucp object for UCP, an agent card's name plus an interface field for A2A, and a linkset for RFC 9727 api-catalog. Every host also gets a nonsense control path. Thousands of sites answer 200 to any URL, and counting by status code alone would credit them with every standard.
• Who runs it. For UCP, the document's own endpoints decide the operator. It is shopify or wix when they point at the platform, and self when they are on the provider's own domain.
• What it does not show. A site that blocks automated requests reads as a miss, so these counts are lower bounds. The probe identifies itself as APIEvangelistBot.

Generated by scripts/probe_standard_wellknown.py and scripts/build_standard_evidence.py. Each standard's page shows the providers measured for it, for example UCP and A2A.