All stages · Demo 377

Guatemala NIT

Choice gt / vat / other. Seven digits plus 0–9 or K. Jev never mods 11. Seven digits need the check.

ChoiceGT mod-11 in JS

A digit tape. 12345679 books a SAT plate. A last-digit flip rejects. Seven digits never pass.

replaykind —gt —

STANDBY

All 4056 stages

Educational stage on jev.page — not the official TypeSafe console. Live calls go to POST https://api.typesafe.ai/v1/systemone from your browser when you paste a key. Without a key, the stage plays a recorded decision shaped like jev-1.13.0. Jev does not write the UI copy.