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Bold Checkout APIs give you full control of your online store’s checkout. Use the APIs to customize the look and feel of your checkout to align with your brand, integrate payment gateways and flexible payment options, and remove the friction from your customers’ checkout experience.

Bold offers three Checkout APIs:

  • Checkout Backend API — As one portion of a headless checkout, the Checkout Backend API performs tasks such as initializing an order, adding an authenticated customer, and capturing payments. These calls are made from a secure server rather than from a browser, so they only require an API access token.
  • Checkout Frontend API — As one portion of a headless checkout, the Checkout Frontend API performs user-driven functions, such as adding and editing cart line items, editing billing and shipping addresses, and choosing a shipping method. Because these requests are triggered by customer actions in a browser or similar client, these requests require the use of a temporary JSON web token (JWT) to authenticate changes to an order on a customer's behalf.
  • Payment Isolation Gateway Interface (PIGI) API — The interface that a customer uses to input their payment information and add the payment method to an order. PIGI isolates customer payment information from everything else that happens during a checkout experience. This separation increases the security of the customer’s payment information by preventing any third party scripts from having access to information shoppers input into the payment fields.

The content in this section of the Developer Documentation applies only to Bold Checkout APIs (called Bold Cashier on Shopify) that access The same applies to the Checkout Backend and Checkout Frontend API specifications.

If you are looking for earlier versions of the Bold Checkout APIs, which access, refer to the following pages:

What are some example use cases?

You can use the Bold Checkout APIs to change and extend Checkout in a variety of ways. There are several mechanisms to do so:

  • Create a custom “head” for Bold Checkout by using the Checkout Frontend and Checkout Backend APIs on
  • Create an integration, which extends the functionality of Bold Checkout by using the Checkout Frontend and Checkout Backend APIs on
  • Create a plugin, which extends the functionality of Bold Checkout using events and actions.

The following table includes a variety of use cases and the mechanisms that enable them:

Use caseRecommended solution
Create transaction experiences anywhere, including emerging channels like IoT, voice, and kiosks.Custom head
Create a one-click checkout that enables customers to complete their transaction quickly, with payment methods they trust (i.e. wallet pays).Custom head
Customize the customers’ visual experience to create a unique, branded checkout that matches your store’s look and feel.Custom head
Use data from the Bold webhooks to inform marketing strategy (i.e. sending custom abandoned cart emails).Integration
Check that all orders adhere to your area’s compliance requirements, and cancel orders that violate these requirements.Plugin or Integration
Add a one-time fee to every order, such as an eco fee, cleaning fee, etc.Plugin
Provide a discount if the customer’s purchase is above a certain threshold.Plugin
Create a bridge between Bold Checkout and a third-party tax provider.Plugin
Create a bridge between Bold Checkout and a third-party shipping provider.Plugin
Flag an order as Buy Online, Pickup In Store (BOPIS) and set the shipping address to the store where the order should be picked up.Plugin

If you are not sure whether your use case requires a plugin, integration, or custom head for a headless checkout, reach out to [email protected].

What platforms are supported?

Bold’s Checkout APIs are headless and enable you to couple our APIs with any front-end experience you choose. You can choose any existing ecommerce platform, or create a store entirely from scratch.

While it is possible to use the Bold APIs with any ecommerce platform, most stores that Bold supports are on the following platforms:

  • BigCommerce
  • commercetools
  • Shopify

If you would like to use the Checkout APIs with another platform, reach out to our Partners team.


Bold Checkout is called Bold Cashier on Shopify. Bold Cashier is only available to merchants who installed the app prior to January 20, 2020. New enterprise customers can submit a request to Shopify to use Bold Cashier. Please reach out to our Partners Team for more information.

How do I get started?

If you are ready to jump in, the Checkout Getting Started page gives you everything you need to know to begin building a checkout with Bold APIs.