Retry strategies

The API responds with transient codes (429, 5xx) and permanent ones (4xx except 429). Only the transient codes and network errors are worth retrying, always with exponential backoff and jitter.

Quick decision


function shouldRetry(err) {
  if (!err.response) return true;  // network error
  const status = err.response.status;
  if (status === 429) return true;
  if (status >= 500 && status < 600) return true;
  return false;
}

Exponential backoff with jitter


const backoffMs = (intento) => {
  const base = Math.min(1000 * Math.pow(2, intento), 30000);
  const jitter = Math.random() * 1000;
  return base + jitter;
};

Complete pattern


async function callWithRetry(fn, maxRetries = 5) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await fn();
    } catch (err) {
      if (!shouldRetry(err) || i === maxRetries - 1) throw err;
 
      // If there's a Retry-After, respect it
      const retryAfter = err.response?.headers['retry-after'];
      const waitMs = retryAfter ? parseInt(retryAfter) * 1000 : backoffMs(i);
      await sleep(waitMs);
    }
  }
}