Errors

const RETRYABLE_STATUS = new Set([429, 500, 502, 503, 504]);

class PermitcoreError extends Error {
  constructor(status, type, detail) {
    super(detail);
    this.status = status;
    // Stable identifier to branch on — e.g. ".../errors/invalid-credentials".
    this.type = type;
  }
}

async function callPermitcore(path) {
  const res = await fetch(`https://api.permitcore.io${path}`, {
    headers: {
      Authorization: `Bearer ${process.env.PERMITCORE_API_KEY}`,
      Accept: "application/json",
    },
  });
  if (!res.ok) {
    // RFC 9457 problem+json: { type, title, status, detail, instance, request_id }
    const body = await res.json().catch(() => ({}));
    throw new PermitcoreError(res.status, body?.type, body?.detail);
  }
  return res.json();
}

async function withRetries(fn, maxAttempts = 4) {
  let lastErr;
  for (let attempt = 1; attempt <= maxAttempts; attempt++) {
    try {
      return await fn();
    } catch (err) {
      lastErr = err;
      const retryable = err instanceof PermitcoreError && RETRYABLE_STATUS.has(err.status);
      if (!retryable || attempt === maxAttempts) throw err;
      const delay = Math.min(2 ** attempt * 1000, 30000);
      await new Promise((r) => setTimeout(r, delay));
    }
  }
  throw lastErr;
}

// Usage:
const data = await withRetries(() => callPermitcore("/v1/jurisdictions/nyc/cohorts/distribution"));