Handle rate limits gracefully

Avoid the limit

Cache responses that rarely change (product data, loyalty tiers), coalesce duplicate in-flight requests, and throttle client-side so you never burst past the window. See Rate limits and 429.

Recover from a 429

On a 429, read Retry-After (seconds) and wait at least that long before retrying. Add jitter so many clients do not retry in lockstep.

if (res.status === 429) {
  const wait = (Number(res.headers.get('Retry-After')) || 1) + Math.random();
  await sleep(wait * 1000);
  return retry();
}

Design for it

Rate limiting is defence-in-depth, not a reliability gate. Treat a 429 as a normal, expected signal to slow down — not an error to surface to users.