To some extent, T166605: Loading links content only once on hover [Proposal] and T161284: Minimise incidental HTTP requests caused by Page Previews both suggest that API responses should be cached in-memory. However, Page Previews (PP) uses APIs that can be – and are! – cached by the browser:

In T166605#3317476, @phuedx wrote:

… PP leverages the browser's cache rather than maintaining its own. We rely on Grade A browsers implementing HTTP caching correctly and their vendors making accessing them as efficient as possible in order to avoid incurring the incidental complexity of writing our own cache in JavaScript. I think this is reasonable.

This reads like an architecture decision and should be documented as such.

AC

• An ADR is added to the PP codebase explaining this decision.