Fraud Alert
Try it
A credit card alert that scales with certainty
THE IDEA
Most fraud alerts sound the alarm the same way whether the system is sure or just checking. I wanted one that matches its tone to its confidence. When it's certain, it pauses the charge and says so. When it's unsure, it just asks. The whole piece protects the cardholder's calm, not only their money.
WHAT I LEARNED
The model defaults to alarm. Its first pass went red at every level. Real apps like Monzo and Revolut reserve red for declined charges, so I moved the high tier to a protective amber.
A percentage needs an object. "94% confident" means nothing alone. I made it read "94% confident this wasn't you," and capped it at 99, because no system is ever fully sure.
I overrode the AI more than I accepted it. It proposed inverting the confidence number, which would have broken the meter. I turned it down. Directing the model mattered more than prompting it.
BUILT WITH
v0 · Cursor · Mobbin · Vercel · 2026
Fraud Alert
Try it
A credit card alert that scales with certainty
THE IDEA
Most fraud alerts sound the alarm the same way whether the system is sure or just checking. I wanted one that matches its tone to its confidence. When it's certain, it pauses the charge and says so. When it's unsure, it just asks. The whole piece protects the cardholder's calm, not only their money.
WHAT I LEARNED
The model defaults to alarm. Its first pass went red at every level. Real apps like Monzo and Revolut reserve red for declined charges, so I moved the high tier to a protective amber.
A percentage needs an object. "94% confident" means nothing alone. I made it read "94% confident this wasn't you," and capped it at 99, because no system is ever fully sure.
I overrode the AI more than I accepted it. It proposed inverting the confidence number, which would have broken the meter. I turned it down. Directing the model mattered more than prompting it.
BUILT WITH
v0 · Cursor · Mobbin · Vercel · 2026