Connect Canvas Desktop. This page is ready
Canvas Desktop does not take a Shopify email or password. Open the Canvas app inside Shopify Admin so the store can issue a one-time device code.
canvas:// deep link, or paste the one-time code in Desktop → Your store.Codes expire in a few minutes. Each person uses their own staff login and their own computer. Drafts stay local until Review & publish.
ATH production is canvas-15 (client 3e4af208…). Do not open …/apps/athcli3 — that install 401s against buildwithcanvas.com.
/app in a normal browser window to log Desktop in — that path is for the embedded Admin app only.