What Does Fail-Closed Mean in Screening?
Fail-closed explained — and why it is the safe mode for agent payments.
TL;DR
TL;DR: Fail-closed means: if the screen cannot run, the payment does not happen. The alternative — fail-open — lets money move unscreened, which is how violations happen.
The two modes
| Mode | Screen down → | Risk |
|---|---|---|
| Fail-closed | Payment blocked | Availability (agents pause) |
| Fail-open | Payment proceeds | Missed violation ($356,000+) |
The honest trade
Fail-closed costs uptime; fail-open costs money. For payment paths, the asymmetry is decisive — a blocked payment is a retry, a missed violation is a fine.
The implementation
Screen before sign; on error, block and log. That is fail-closed in one sentence.