overview / faq / Will it slow my session?
No meaningfully. The gate is deterministic native C++ and decides in 2.8 ms at the median (2.78 ms allow, 3.70 ms deny, n=40); the hook timeout it runs inside is measured in seconds. The hot path never calls a model. Reproduce the number with make bench — it prints the table BENCHMARK.md is built from.
One action is deliberately not free: a git push when code changed after the last green test run. There the gate runs your suite before it opens, so that one hook call costs whatever your tests cost.