Rate limits & throttling

{
  "detail": "API Calls limit reached."
}

const response = await fetch(url);

if (response.status === 429) {
  const error = await response.json();
  console.log('API limit reached:', error.detail);
  // Check Retry-After header and wait until the monthly reset
}

# Bad — triggers a redirect, counts as 2 API calls
GET /v2/posts?auth_token=TOKEN

# Good — single request, counts as 1 API call
GET /v2/posts/?auth_token=TOKEN

# Fetch multiple collections in one request
GET /content/?keys=categories,tags,authors

# Let ButterCMS resolve references automatically
GET /pages/homepage/?levels=2

const cache = new Map();
const CACHE_TTL = 5 * 60 * 1000; // 5 minutes

async function fetchCached(url) {
  const cached = cache.get(url);

  if (cached && Date.now() - cached.timestamp < CACHE_TTL) {
    return cached.data;
  }

  const response = await fetch(url);
  const data = await response.json();

  cache.set(url, { data, timestamp: Date.now() });

  return data;
}

let requestCount = 0;
const requestLog = [];

async function trackedFetch(url) {
  requestCount++;
  const start = Date.now();

  const response = await fetch(url);

  requestLog.push({
    url,
    status: response.status,
    duration: Date.now() - start,
    timestamp: new Date().toISOString()
  });

  return response;
}

// Periodically review usage
setInterval(() => {
  console.log(`API requests in last hour: ${requestCount}`);
  requestCount = 0;
}, 3600000);