v1.0.0

circuit v1.0.0

First stable release of the circuit breaker library.

Features

• Generic Run[T] — type-safe execution with no type assertions
• Two-step mode — Allow/done pattern for HTTP middleware and gRPC interceptors
• Functional options — clean With* configuration API
• Lazy state evaluation — zero background goroutines, no Close() needed
• Probabilistic throttling — gradual recovery with 5 built-in backoff curves (Linear, Logarithmic, Exponential, EaseInOut, JitteredLinear)
• Error classification — WithIsSuccessful and WithIsExcluded callbacks
• Panic handling — panics in runners are recorded as failures and re-raised
• Observability — MetricsCollector interface with error detail, state change channel, OnStateChange callback, Snapshot() for health endpoints
• BreakerBox — manage multiple named breakers with centralized state change forwarding
• Contextual errors — all circuit errors carry breaker name and state, compatible with errors.Is and errors.As
• Production hardened — fast-path lock avoidance, throttled eviction, TOCTOU-safe LoadOrCreate

Requirements

• Go 1.22+
• Zero external dependencies