WebMCP (Shopify storefront adapter)

What ARC sees

Live: n = 3,308 stores with a completed HTTP check, latest as of 9 Oct 2026 (UTC). Live figures (n = 3,308) update hourly from saved checks. Downloads are the dated weekly snapshot 2026-10-09.r3, n = 3,308, so their counts can differ.

What ARC checks

• Detects Shopify's WebMCP adapter in the store's server HTML.
• The Index runs five browser shoppers per store that try to reach the cart and stop before payment.

What ARC can't check from outside

• Whether tools register in a live browser session.
• ARC's browser shoppers do not call WebMCP tools, so the Transacts figure is an association, not proof WebMCP was used.

Methodology

Counts use each store's latest completed HTTP check saved by ARC. Failed checks are left out of the denominator. Each host counts once.

Measured means ARC observed it directly. Inferred means ARC links two observations that do not prove each other. Not measured means ARC has no saved evidence, and the count is not zero adoption.

A checkout link means a cart was created for one real product. It is not a completed purchase. ARC never places orders.

The sample is ARC's curated store list plus stores people checked. It is not all of e-commerce. Treat percentages as rates in this sample.

Reads make no store requests and no model calls.