Circuit breaker

Add circuit when an upstream API is flaky or failing and you want the stitch to stop hammering it. After a run of failures the breaker opens and calls fast-fail for a cooldown: the stitch backs off, giving the unhealthy dependency room to recover before a single trial call probes it again — and shielding your app from the slow, cascading failures a dead upstream would otherwise pull it into.

Example

import { stitch } from 'stitchapi';

const orders = stitch({
    baseUrl: 'https://api.example.com',
    path: '/orders',
    circuit: { failures: 5, cooldown: 30_000 },
});

After 5 consecutive failures the breaker opens; for the next 30 seconds calls to orders() fast-fail instead of hitting api.example.com.

Options

The breaker moves through four states. It starts closed (calls pass through). After failures consecutive failures it trips open and calls fast-fail for cooldown. It then goes half-open and lets a single trial call through: a success closes it and clears the count, another failure re-opens it for a fresh cooldown. The breaker emits progress events with phase circuit.

failures and cooldown are both required — failures is the count of consecutive failures that trips the breaker open, and cooldown is the fast-fail window after opening, before a half-open trial is allowed.

halfOpenAfter controls when the half-open trial is permitted (default cooldown), letting you fast-fail and probe on different clocks.

key is a store namespace: give two stitches the same key plus a shared store to share one breaker, so a failing host opens the circuit for every stitch that talks to it. The default key is the stitch/host key.

See Reference → Config types for every field.

See also