# Quickstart

> For the complete documentation index, see [llms.txt](/llms.txt).

Take a real payment in the Unipaas sandbox with a single server-to-server call, no vendor setup and no onboarding. You create a checkout, open the link Unipaas returns, and pay it with a test card. That same call hands you everything you need to choose your integration path next.

## Before you start

* A sandbox account. [Create one](https://portal.unipaas.com/signup); it is free and instant.
* Your sandbox private key, from your portal account settings.
* The sandbox base URL: `https://sandbox.unipaas.com/platform`.

## Create a checkout

Make one call from your server to create a checkout. It takes your private key in the `Authorization` header and four fields: the amount, the currency, the shopper's country, and their email. Amounts are in the major currency unit, so `10` is 10.00.

Caution

This call runs on your server. It uses your private key, your secret credential, which must never be exposed in the browser.

```curl
curl -X POST https://sandbox.unipaas.com/platform/pay-ins/checkout \
  -H "Authorization: Bearer <PLATFORM_API_KEY>" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 10,
    "currency": "GBP",
    "country": "GB",
    "email": "shopper@example.com"
  }'
```

## See it work

Unipaas responds with `201 Created` and the checkout object. Two fields matter right now:

```json
{
  "id": "6839...c1d",
  "status": "open",
  "amount": 10,
  "currency": "GBP",
  "shortLink": "https://sandbox-checkout.unipaas.com/-0_lisK298/",
  "sessionToken": "eyJhbGciOiJI...",
  "expiresAt": "2026-06-25T18:30:00.000Z"
}
```

* `shortLink` is a hosted checkout page. Open it in your browser.
* `sessionToken` is a short-lived token for the embedded Web SDK path; you use it below.

Open the `shortLink`. You will see a branded, PCI-compliant checkout for the amount you set. Pay it with a [test card](/docs/test-cards/) to complete your first sandbox payment.

## Next steps

You have taken a payment. Now choose how to integrate:

* **Hosted checkout** - redirect shoppers to the `shortLink` you just used. See [Checkout Page](/docs/checkout-page/).
* **Embedded Web SDK** - keep shoppers on your page with Unipaas-hosted secure card fields, using the `sessionToken` from the call above. See [Web SDK](/docs/web-sdk/).
* **Client-side calls** - if your app calls Unipaas from the browser, such as embedded onboarding, mint a scoped token first. See [Authentication](/docs/authentication/).