asyncbreaker 2.0.1

Asyncio Circuit Breaker pattern with optional Redis storage.

asyncbreaker is an asyncio-first Python implementation of the Circuit Breaker pattern from Michael T. Nygard’s book Release It!.

Circuit breakers let one subsystem fail without taking down the whole application: you wrap risky calls (often I/O or integration boundaries) so that repeated failures trip the breaker, subsequent calls fail fast for a reset timeout, then a single trial call may close the circuit again.

Lineage

• pybreaker (Daniel Fernandes Martins) — original design.

• aiobreaker fork (Alexander Lyon) — asyncio instead of Tornado, packaging experiments.

• Current line — maintained by Sergey Turbinov; substantial rewrite toward a pure async API, async storage, and async listeners. Contact: @freems on Telegram.

Features

• Async CircuitBreaker — use await breaker.call(...)

• Configurable failure threshold (fail_max) and reset window (timeout_duration)

• Excluded exceptions and predicate callables (business vs system errors)

• Multiple async CircuitBreakerListener instances

• Pluggable async storage: in-process memory or Redis via redis.asyncio

• Optional redis extra for Redis-backed storage

Requirements

Python 3.10+ (async patterns and typing used throughout).

Installation

pip install asyncbreaker

With Redis support (redis package):

pip install asyncbreaker[redis]

Usage

Create a breaker per integration point. Only async callables are supported; the decorator rejects ordinary def functions.

from datetime import timedelta

from asyncbreaker import CircuitBreaker

api_breaker = CircuitBreaker(fail_max=5, timeout_duration=timedelta(seconds=60))

@api_breaker
async def fetch_remote():
    ...

# or explicitly:
await api_breaker.call(fetch_remote)

See the Usage chapter in the full documentation (docs/) for listeners, storage, manual open / close / half_open, and exclusion rules.

Documentation

Build locally:

pip install -e '.[docs]'
sphinx-build docs/source docs/build

The HTML entry point is docs/build/index.html.

License

BSD 3-Clause; see license.md. This project bundles copyright from the pybreaker lineage; additional copyright applies to the asyncio rewrite (see license.md).