How we measure usage

What this site measures, the two first-party cookies it uses, and how to switch measurement off with one click.

This library exists to be a reference: something you find, read, come back to, and cite. To know whether a page is doing that job, we measure how it is actually used. Nothing here is advertising, profiling, or cross-site tracking. The numbers exist to decide which pages earn their place and which need work.

What gets recorded

When you read a page, the site sends a small measurement event to our own server (/api/engage). It records:

• which page you read, and how far down it you got
• how long you were actively reading (not just how long the tab was open)
• the website you arrived from (the site name only, never the full address)
• clicks on “what to read next” and links to our other sites
• whether you copied something from the page

It deliberately does not record your IP address, your full browser details, search terms, or anything you type. Raw measurement records are deleted after 90 days; only aggregate statistics (views, read-through rates, return visits per page) are kept.

The two cookies

Cookie	Purpose	Lifetime
nkda_mid	A random identifier with no personal meaning. It lets us count that the same browser came back to a page on a later day, which is the clearest sign a page works as a reference.	13 months
nkda_mopt	Records that you switched measurement off.	5 years

Both are first-party: they are set by this site, sent only to this site, and shared with nobody. There is no analytics vendor involved; the data goes to our own storage and stays there.

Switching it off

Use the Usage measurement toggle in the footer of any page. One click, no account, no questions. Opting out deletes the nkda_mid cookie and stops all measurement for this browser: you become invisible to it, not anonymised within it.

This site relies on the UK PECR statistical exception for first-party audience measurement, which is why there is no consent banner: the measurement is statistics-only, first-party, and paired with this notice and the one-click objection. Questions? Email martin@nkdagility.com.