const openfuse = new OpenfuseCloud(...);

what happens when your service goes down

It is answered in the FAQ at the bottom of the page

"The SDK is fail-open by design. If our service is unreachable, it falls back to the last known breaker state.

If no state has ever been cached (e.g., a cold start with no connectivity), it defaults to closed, meaning your protected calls keep executing normally. Your app is never blocked by Openfuse unavailability."

Yup, that is true for both Cloud and Self-hosted, it never blocks any executions by any external factors other than the breaker is KNOWN as open. The state sync and the hot path are 2 completely separated flows.

Feel free to take a look at the SDK code if you want to, it's open :) https://github.com/openfuseio/openfuse-sdk-node