Developer documentation

Generate a payment link

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A payment link is a hosted URL that opens the UnitPay payment form pre-filled with an amount, currency, and description. Customers pay through the same hosted experience as the API-driven flow; you receive the result through the same callback handler. Two ways to generate one:

  1. From the merchant cabinet — add a product, copy the link, share it. No code required.
  2. Programmatically — call initPayment from your server and reuse the returned redirectUrl as a one-time payment link.

Option 1 — create a link from the merchant cabinet

Use this when you sell a fixed catalogue of items, accept donations, or need a quick reusable link without integrating the API.

  1. Sign in to the merchant cabinet and open Settings → Products for your project.
  2. Click + Add product and fill in the fields:
    • Name — shown on the payment form and the receipt.
    • Price and Currency — IDR, USD, or EUR.
    • Description — optional details displayed alongside the product name.
    • Quantity policy — fixed price, customer-entered amount, or limited stock.
    • Locale — the form language, en or id.
  3. Save. The cabinet generates the payment link and a printable QR code that resolves to the same URL.
  4. Share the link by email, WhatsApp, or any other channel; embed the QR on a printed receipt or in-store sign.

You can edit, deactivate, or delete a product at any time. Deactivating an existing link prevents new payments but does not cancel pending or completed transactions.

Option 2 — reuse the redirectUrl from initPayment

Use this when each link must carry an order-specific amount, customer reference, or short expiry. Call initPayment with the order details, then deliver the redirectUrl from the response to the customer:

POST https://api.unitpay.net/api
Content-Type: application/x-www-form-urlencoded

method=initPayment
&params[paymentType]=card
&params[projectId]=123456
&params[sum]=150000.00
&params[currency]=IDR
&params[account]=invoice-2026-0184
&params[desc]=Invoice%20%232026-0184
&params[signature]=<sha256-hex-digest>

The response carries the hosted URL:

{
  "result": {
    "type": "redirect",
    "paymentId": 1231231234,
    "redirectUrl": "https://pay.unitpay.net/123456-1fc2f/card?..."
  }
}

Send the redirectUrl to the customer in your invoice email, ticketing system, or chatbot reply. The link is single-payment and expires when the payment is completed, abandoned, or after the project's payment-window timeout (15 minutes by default).

Choosing between the two options

NeedRecommended option
Fixed price catalogue, social-media checkout, donation pageCabinet product link
Per-invoice amount, server-generated reference, short expiryinitPayment + redirectUrl
Print on a physical receipt with QR codeCabinet product link
Embed in transactional email triggered by your backendinitPayment + redirectUrl

What you receive after a payment

Both options notify your callback handler the same way: a signed CHECK request followed by a signed PAY request, both verifiable using your project secret key. See Callback handler. The account field in the callback echoes the customer or order identifier you set on the link, so you can reconcile the payment to the originating order.

Limitations

  • Cabinet product links use the project's primary currency by default; multi-currency catalogue items require one product entry per currency.
  • redirectUrl values are not designed to be re-shared after the customer has used them — generate a fresh link per invoice.
  • Link domains are fixed to pay.unitpay.net. Custom domains are on the roadmap; ask onboarding for the current status.

Next steps