API & partners

Build payments
into your software

One REST integration gives your users all three ways to get paid — online, on a phone, on a terminal. The sandbox is available the moment you sign up, and you earn a recurring commission on every payment your merchants take.

Explore the API Become a partner

Test keys straight away, no commercial approval required.

REST / cURLNode.jsPythonWebhooksSandbox
Endpoints

One REST API, three ways to get paid

You create a payment with the same object, whether it's taken online, on a phone or on a terminal. Signed webhooks notify you of every status change.

POST/checkout-sessionsCreate a checkout — link, QR or hosted page
GET/checkout-sessions/{id}Status and full lifecycle of a checkout
GET/transactionsRead & reconcile, VAT per line
POST/refundsPartial or full refund
POST/subscriptionsRecurring billing on a stored card
POST/subscription-plansShareable plans your customers subscribe to
GET/terminalsList the terminals of a store
POST/terminal-chargesTrigger a payment on a physical terminal

Base URL https://app.nextepay.com/api/v1 · Authorization: Bearer your key · Idempotency-Key on every write

Full API referenceQuickstart, every parameter, errors, test cards — in your space, keys includedServer statusLive availability of the API, the payment page and the payouts
Webhooks

Signed, reliable, idempotent

Every event fires a webhook signed with HMAC-SHA256. Your backend checks the signature before doing anything — automatic retry if you don't respond.

  • HMAC-SHA256 over timestamp.body, sent as X-Nextepay-Signature
  • X-Nextepay-Timestamp, X-Nextepay-Event and X-Nextepay-Delivery-Id travel with it
  • Event fields live under data — your own reference comes back untouched
  • Automatic retry with backoff if your endpoint doesn't answer
  • Test and production keys, revocable from your space
Webhook — transaction.succeededsigned
{
  "event": "transaction.succeeded",
  "data": {
    "transaction_id": "…",
    "reference": "order-1234",
    "status": "succeeded",
    "amount_cents": 2500,
    "currency": "EUR"
  }
}
→ your backend verifies the signature, then confirms the order
Getting started

From the first request to production

1
pk_test_… / sk_test_…

Create your developer account

You get your test keys and make your first call within the day.

2
simulate: success · declined · timeout

Integrate and test

You wire up the webhooks and run your flows in the sandbox. Our engineering team answers your integration questions.

3
pk_live_… ✓ go-live

Go to production

We validate your integration with you, and your merchants start getting paid.

Partner programme

Every payment your merchants take
pays you

You earn a recurring commission on the volume taken by the merchants you've integrated. It's visible in real time in your partner space and paid out automatically every month.

  • The programme is contractual: the share, the calculation and the payout are set out in the partner agreement.
  • You track your volume and your commission merchant by merchant.
  • Your clients keep a Nextepay account in their own name; you keep the product relationship.
Become a partner
Partner space3 active merchants
Boutique Martin     12,480 €  +124.80 €
Café Central         8,920 €  +89.20 €
Studio Dupont        3,640 €  +36.40 €

— commission this month —
Total               250.40 €
Automatic payout on the 1st of the month
Free sandbox

Your test keys in a few minutes

You create your account, get your sandbox keys and make your first call within the day. For the partner programme, a technical and commercial call can be set up within a week.

Explore the API Contact our team