Class CircuitBreaker

Circuit breaker preventing cascading MCP failures.

CLOSED — normal operation; all requests pass through.
OPEN — fast-fail; requests are rejected for resetTimeoutMs ms.
HALF_OPEN — probe state; one request is allowed to test recovery.

Index

Constructors

Properties

state consecutiveFailures nextAttemptAt halfOpenProbeInFlight failureThreshold resetTimeoutMs

Methods

canRequest recordSuccess recordFailure getState getStats

Constructors

constructor

new CircuitBreaker(options?: CircuitBreakerOptions): CircuitBreaker
Parameters
- options: CircuitBreakerOptions = {}
Returns CircuitBreaker
- Defined in generators/pipeline/fetch-stage.ts:83

Properties

`Private`state

state: CircuitState = 'CLOSED'

`Private`consecutiveFailures

consecutiveFailures: number = 0

`Private`nextAttemptAt

nextAttemptAt: number = 0

`Private`halfOpenProbeInFlight

halfOpenProbeInFlight: boolean = false

`Private` `Readonly`failureThreshold

failureThreshold: number

`Private` `Readonly`resetTimeoutMs

resetTimeoutMs: number

Methods

canRequest

canRequest(): boolean
Whether a request may proceed given the current circuit state.

In HALF_OPEN state only a single probe is allowed at a time; subsequent calls return false until the in-flight probe records success or failure.

Returns boolean
true when the circuit is CLOSED, or HALF_OPEN with no probe in flight
- Defined in generators/pipeline/fetch-stage.ts:96

recordSuccess

recordSuccess(): void
Record a successful request and close the circuit

Returns void
- Defined in generators/pipeline/fetch-stage.ts:114

recordFailure

recordFailure(): void
Record a failed request.
- When in HALF_OPEN the circuit re-opens immediately (the probe failed).
- When in CLOSED the circuit opens only once the failure threshold is reached.
Returns void
- Defined in generators/pipeline/fetch-stage.ts:126

getState

getState(): CircuitState
Return the current circuit state.

Returns CircuitState
Current circuit state
- Defined in generators/pipeline/fetch-stage.ts:150

getStats

getStats(): Readonly<{ state: CircuitState; consecutiveFailures: number }>
Return current statistics for observability.

Returns Readonly<{ state: CircuitState; consecutiveFailures: number }>
Snapshot of state and consecutive failure count
- Defined in generators/pipeline/fetch-stage.ts:159