I started this while waiting for the bus to the festival. I have Hermes, an AI coding agent running on my VPS, connected to a Telegram group. I sent it a short request: “Build me the timetable.”I kept using the app during the festival and requesting changes from my phone. An unfamiliar artist led to Spotify links, finding stages led to an interactive map, and the cashless wristband led to the most interesting feature: estimating its balance from the credit-limit error returned by the official checkout flow.The project was intentionally temporary and practical. The balance feature no longer works because the event checkout has ended, but the PWA and its revision timeline remain available to explore. I’d be interested in feedback on this kind of software built for a very specific, short-lived problem.