ExponentialBackoff

Retry policy with exponential delay growth and an upper delay bound.

ExponentialBackoff increases delay over time, reducing pressure on unstable upstream services.

Import

import { ExponentialBackoff } from "@zap-studio/retry/exponential-backoff";

Configuration

const policy = new ExponentialBackoff({
  maxAttempts: 6,
  baseDelayMs: 100,
  maxDelayMs: 5_000,
});

Delay Model

Delay grows exponentially and is capped:

attempt 1 -> baseDelayMs
attempt 2 -> baseDelayMs * 2
attempt 3 -> baseDelayMs * 4
...
capped at maxDelayMs

When to Use

Use ExponentialBackoff when:

retries target shared/networked services
transient failures are common
aggressive immediate retries could amplify outages

Example

import { $fetch } from "@zap-studio/fetch";

const policy = new ExponentialBackoff({
  maxAttempts: 5,
  baseDelayMs: 100,
  maxDelayMs: 2_000,
});

const user = await policy.run(async () => {
  const response = await $fetch("https://api.example.com/users/1", {
    throwOnFetchError: true,
  });
  return await response.json();
});

Last updated on

FixedDelay

Retry policy with a constant delay between attempts.

Running Policies

Use BaseRetryPolicy.run for built-in orchestration with optional custom sleep behavior.

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