// challenge

what is arkose matchkey?

a captcha-widget challenge; used by arkose-labs; mints the arkose verify-token checked server-side token; escalation: low risk: a single short matchkey game (or suppressed) → elevated risk: more rounds, harder 3d/visual matches → block on repeated failure. funcaptcha successor: adaptive "matchkey" puzzles whose difficulty + round count scale with session risk; art rotates frequently to resist farming, making it the hardest challenge to automate cheaply.