Detection is a claim about what is happening. This is the contract that acts on it, and you deploy, own and revoke it. Fuga Labs signs a statement and never touches the brake, which is why a total compromise of us buys an attacker one alert and nothing else.
This is the distinction the category is most often sold past. The Circuit Breaker is opt-in and ships disarmed; what follows is what it does once you arm it.
Your contract asks its own policy contract before it acts. When a transaction fails your rules it reverts inside that same transaction, with no round trip to us and no dependency on us being alive. This is the half that stops an atomic exploit.
Works with Fuga Labs completely offline.
A finding arrives and the standing policy gets stricter: a lower cap, a restricted account, a paused scope. This is slower than the transaction that triggered it, which is why it answers the other shape of attack, the drains that take minutes rather than microseconds.
Both are real. They answer different attacks.
The path a deployment travels. The order is a recommendation; what is enforced sits on the last two rungs, neither of which publishes until the shadow period has earned it.
Every deployment starts here and publishes nothing at all. It is also where the kill switch returns it, in one transaction you hold, without asking us and without waiting for us.
It evaluates everything and still publishes nothing, recording what it would have done against your own live traffic. This is the rung that manufactures the evidence the next two are gated on.
It publishes for an explicit allowlist of subjects under a tightened ceiling. Refused outright until the shadow period clears a measured soak, enough distinct subjects, and no legitimate transaction that would have been reverted.
It publishes for every subject under the policy you set. Each attestation carries a mandatory expiry, so nothing this breaker holds ever becomes a standing authority over your protocol.
One breaker, five sources. A wall does not ship a brake of its own; it reaches the same policy contract you already deployed.
Fuga Labs is read-and-attest, never custody-and-execute.
A scoping call decides which wall drives the breaker, what its one bounded action is, and what evidence must accumulate before you arm it. All three are written down first.