interlock¶

A modern circuit breaker for Python — sync and async in a single class, sliding-window rate and slow-call detection, a type-safe API, and transparent integrations at the transport level.

Why interlock¶

• Sync and async, one class. A single CircuitBreaker detects coroutine callables and dispatches to the right path — no Sync*/Async* twins.
• Sliding windows by rate. Both count-based and time-based windows, not the naive consecutive-failure counter found elsewhere in the ecosystem.
• Slow-call detection. Treat calls slower than a threshold as failures — not available in any other Python circuit breaker.
• Type-safe. ParamSpec + TypeVar decorators that preserve signatures; ships py.typed and passes mypy in strict mode.
• Zero-dependency core. Standard library only; everything external lives in optional extras.

Installation¶

uv add interlock-cb

Status¶

interlock ships v1.0-first: a polished core (state machine, windows, sync/async, slow-call detection) before breadth. Distributed state, retries, and a full resilience pipeline are planned for later releases.