Permanently delete a key owned by the authenticated user. A missing key or a key owned by another user returns 404. Deletion cannot be undone. Current-format keys are checked for revocation on each Core API request.

Older keys may continue authenticating after deletion while legacy-key acceptance is enabled, until their expiration if one was set. Older keys without an expiration have no time-based cutoff. Replace older keys with newly created keys; replacement alone does not invalidate an old key.