Pagination

Each list response has nextBefore. When it is a number, pass it as before to get the next page. When it is null, you've reached the end. nextBefore is set whenever a page is full, so the last page can occasionally be empty.

Non-numeric limit or before returns 400.

// Node 18+
const base = "https://brazen-raven-302.convex.site/api/v1/customers";
let before = null, all = [];
do {
  const url = before ? `${base}?limit=200&before=${before}` : `${base}?limit=200`;
  const res = await fetch(url, { headers: { Authorization: `Bearer ${process.env.FACTORA_API_KEY}` } });
  const page = await res.json();
  if (!page.ok) throw new Error(page.error);
  all.push(...page.data);
  before = page.nextBefore;
} while (before !== null);