API Overview

Unified Checkout Developer Guide
- Recent Revisions to This Document

Introduction to Unified Checkout

Unified Checkout Quick Start
- Step 1: Enable Unified Checkout
- Step 2: Set Up the Server-Side Component
- Step 3: Set Up the Client-Side Component
- Step 4: Configure Unified Checkout
- Step 5: Test Your Unified Checkout Integration

Unified Checkout Flow

Server-Side Set Up

Client-Side Set Up
- Loading the JavaScript Library
- Complete Integration Examples

Configuration
- Configure the Unified Checkout Merchant Experience
  - Enable Unified Checkout
  - Configure Payment Options
  - Customize the Unified Checkout Look and Feel
  - Look and Feel UI Examples
  - Configure Customer Data and Payment Flow
  - Capture Context Fields in the Smartpay Fuse Portal
  - Manage Permissions
    - Managing Permissions as an Administrator
- Process Payments with Unified Checkout
- Webhooks Support

Transient Tokens
- Transient Token Format
- Token Verification
- Dual-Branded Cards
- Authorizations with a Transient Token

Test Your Configuration
- Unified Checkout Test Cards
- Visa and Mastercard Click to Pay Test Cards
- Test Cards for Authentication by Click to Pay
- Test Authentication
- Handle Errors
- Reason Codes

Payment Details API

JavaScript API Reference

Appendix
- JSON Web Tokens
- Supported Countries for Digital Payments
- Supported Locales
- Update to Unified Checkout Version 1
  - Update Reason Codes
  - Version 1 Update Checklist
- Security Recommendations
- PCI Compliance

On This Page

Client Version

This field is used to specify the Unified CheckoutAPI version that your integration should use.

Barclays recommends that you do no include this field in your

uc/v1/sessions

API request. When you do not include this field, Unified Checkout automatically uses the latest available version. This ensures access to the most recent enhancements and updates without requiring integration changes.

When you include this field, the value must be provided in

MAJOR.MINOR

format (for example,

1.1

or

1.2

). For information about semantic versioning, see Versioning.

IMPORTANT

This field cannot be configured through the merchant experience screens in the Smartpay Fuse Portal.

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