Other plugins on your site (WP Consent API)

WP Consent API is a free plugin on wordpress.org that other plugins read before they set a cookie: WooCommerce's order attribution, Google's Site Kit (for its consent mode) and a growing list of others. With it installed and active, this plugin registers as your site's consent tool and hands each visitor's answer over in their browser, so those plugins follow it. There is no setting: installing WP Consent API is the switch.

Our kinds of cookie map onto theirs: Necessary is their functional (always allowed), Preferences is preferences, Measurement is both statistics and statistics-anonymous, and Advertising is marketing. A kind your banner does not ask about is handed over as refused. The answer is kept in five first-party cookies that WP Consent API writes on your own site; nothing is sent anywhere else. On a network set up with sub-directories they are named for each site too (wp_consent_3_marketing on site 3), as the answer's own cookie is (see Multisite).

It also tells WP Consent API that your site asks first. Without that, WP Consent API treats a visitor who has not answered as having agreed to everything. A visitor you do not ask, because of Who is asked, is handed over in their browser as not asked, which WP Consent API treats as agreed. On your server the same visitor counts as not having agreed to anything: where a visitor is cannot be worked out for a page that is cached, and an answer worked out for one visitor would be served to everybody after them. So a plugin that decides on the server, rather than in the browser, treats visitors from places you do not ask as having refused. WooCommerce's order attribution is not one of those: it is told in the browser.

WP Consent API keeps its cookies for 30 days and writes them again on every page, so they can outlive an answer given here: one that has run out (Remember an answer for), one the visitor deleted, or one given before you pressed Ask everybody again. Until that visitor answers again, other plugins are told nothing is agreed: in the browser, on the first page they see, and on your server, where a page such as the checkout is never cached, from their first request.

What it does not do: it does not install WP Consent API for you, and it does not change what other plugins do with the answer. A plugin that does not read WP Consent API is still held back the usual way, if this plugin recognises it.