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Fast Checkout
Simplify customer experience with one-click checkout
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Global payments coverage
We provide a single integration with over 150 payment providers to make sure that every customer will find the way to pay.
Localized experience
Terminal3 checkout will show your customers only relevant payment methods in local prices and language, simplifying their payment experience.
UI / UX customization
You can change colors and elements of the payment page, or go all the way and customize a complete payment flow.
Your sales, orders, customer behaviour and payment habits can be found in the dashboard to help you analyse business performance.
Fully-packed with Terminal3 features
  • Global coverage in over 190 countries.
  • VAT reporting and remittance.
  • In-house risk management systems.
  • Transactions tracking and sales analytics.
Explore more features
Add Fast Checkout with only few lines of code
With only a few lines of code and a single API integration, you can start selling your digital goods and services on a number of supported platforms.
Fast Checkout widget call
This shows a Terminal3 Fast Checkout widget, where products are available for payment and details are passed via API parameters dynamically (including amount, ID and name, quantity).
Request widget link
GET Example: https://your-store-name.terminal3.com/fast-checkout?
Fast Checkout widget call (server-side)
This allows using Non-Stored Product Call, but sending all the widget parameters via server side and getting a widget session key - one token that can be used for loading the widget. This allows sending data that shouldn't be visible via the browser, such as unique order ID. User can then be redirected to the widget using the generated widget session key.
Request method
POST Example: https://your-store-name.terminal3.com/api/store/your-store-name/fast-checkout?
API Return Value
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  "data": {
    "order_id": 42,
    "token": "c3c093fb66fb5c2200cfcf48c5ac65b2"
Request widget link
GET Example: https://your-store-name.terminal3.com/fast-checkout/42/c3c093fb66fb5c2200cfcf48c5ac65b2
API parameters
Parameter Required Example Description Format
product[0][name] yes coins Product name alphanumeric, up to 256 characters long
product[0][vat] yes 1 VAT category numeric
product[0][sku_id] yes 8904 Product ID alphanumeric
product[0][type] yes fixed Specify whether it is a one-time payment or a subscription with recurring billing. fixed, subscription
product[0][quantity] yes 100 Number of products to be purchased. numeric
product[0][amount] yes 10.00 Total amount to be paid numeric, with "." as decimal delimiter
currency_code yes USD Currency in which customer makes a payment in ISO 3166-1 alpha-2 code SO 3166-1 alpha-2 code of the country
ts no 1486448157 Time when request was initiated, represented as Unix timestamp. If it's older than 60 minutes, user sees an error message numeric, Unix timestamp
sig yes 35f09f1aaaf30ee8acb5f2e045cd332f Sign the checkout with unique code to secure it and disallow unauthorized widget access. Can be found in your Store Settings hexadecimal, 32 characters long, lowercase
sign_version yes 2 Signature version 2, 3
email no customer@example.com Your customer's email. Terminal3 will automatically send a payment receipt and products to the customer string
pingback_url yes https://mystore.com&sign_version=2 Optional URL of pingback listener script where pingbacks should be sent. Overrides the default Pingback URL set up in your Store Settings URL
uid yes customer@example.com ID of a customer in your system (email, unique login name) alphanumeric, up to 64 characters long
Signature calculation
Signature version 3
Signature version 3 is calculated as follows (uses SHA256 hash):
sign = SHA256("PARAM_NAME_1=PARAM_VALUE_1PARAM_NAME_2=PARAM_VALUE_2PARAM_NAME_3=PARAM_VALUE_3...SECRET_KEY") Where SECRET_KEY is your secret key. The additional parameters (e.g. PARAM_NAME_1=PARAM_VALUE_1PARAM_NAME_2=PARAM_VALUE_2) should be sorted alphabetically by the parameter name prior to hash calculation.

You can find secret key under store settings
Signature calculation sample
Please note that Paymentwall API Libraries automatically calculate signatures for the Widget Call as well as for Pingback Validation.

If you still need to calculate the signature explicitly, below is an example of how this can be done using Paymentwall PHP Library at GitHub.
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Paymentwall_Config::getInstance()->set(array('private_key' => 'YOUR_PRIVATE_KEY'));
$signature = (new Paymentwall_Signature_Widget())->calculate(
  $params, // widget params
  $signatureVersion // signature version
For other API libraries (Ruby, Python, Node.js, Java, .NET), signature can be calculated using Widget.calculateSignature method.
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