Redeem codes with the API

customer types code ──► POST /v1/redemptions            201 reserved   (voucher locked, nothing charged)
                         │
     your side succeeds ─┼─► POST /v1/redemptions/{id}/capture   200 captured  → credit the customer
     your side fails    ─┴─► POST /v1/redemptions/{id}/cancel    200 cancelled → voucher usable again
     you do nothing     ──►  after ttl_seconds                   expired       → voucher usable again

import { Vouchereto, VoucheretoError } from './vouchereto-node';
const v = new Vouchereto({ apiKey: process.env.VOUCHERETO_API_KEY! });

export async function topUpWithVoucher(user: { id: string }, code: string, customerIp: string, topUpId: string) {
  let r;
  try {
    r = await v.redemptions.reserve({ code, currency: 'USD', customer_ref: user.id, ttl_seconds: 300 },
                                    { idempotencyKey: `topup-${topUpId}-reserve`, customerIp });
  } catch (e) {
    if (e instanceof VoucheretoError) return { ok: false, reason: e.code };   // show a message per code
    throw e;
  }
  try {
    await wallet.credit(user.id, r.amount_minor, r.currency, { redemptionId: r.id });   // idempotent on r.id
  } catch (e) {
    await v.redemptions.cancel(r.id, { idempotencyKey: `topup-${topUpId}-cancel` });
    throw e;
  }
  await v.redemptions.capture(r.id, { idempotencyKey: `topup-${topUpId}-capture` });
  return { ok: true, amountMinor: r.amount_minor };
}