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The Bold Checkout APIs give you full control of your checkout. Use the APIs to customize the look and feel of your checkout to align with your brand, extend Bold Checkout's capabilities, and remove the friction from your customers’ checkout experience.

Checkout flows

Bold Checkout is designed around checkout flows (Patent Pending): optimized checkout experiences individually designed to serve a specific set of shoppers based user-defined criteria, such as the device they're using, their screen size, or the items in their cart.

Checkout flows fall broadly into two categories:

  • Bold-hosted flows are built and hosted by Bold. These flows can be used without any development work.


    Bold currently supports the use of only one Bold-hosted flow at a time.

  • Self-hosted flows are built and hosted by the merchant (or a merchant vendor). These flows can either have completely custom frontends, or they can take advantage of the Checkout Experience Templates. Bold supports the use of any number of self-hosted flows at a time. For more information, refer to Create a Self-Hosted Checkout-Flow.

  • Partner flows are built by one of Bold's partners. These flows are often intended for a specific platform, technology partner, or other use case.

For more information about flows and their components, refer to the conceptual Checkout flows page.

Bold Checkout APIs

Bold offers a series of OpenAPI specifications that reflect our API capabilities:

APIAuthentication methodDescription
Checkout Backend APIAPI access tokenPerforms tasks such as initializing an order, adding an authenticated customer, and capturing payments.
Checkout Frontend APIJSON web token (JWT)Performs user-driven functions, such as adding and editing cart line items, editing billing and shipping addresses, and choosing a shipping method.
Checkout Admin APIAPI access tokenConfigures store-level settings, including overrides and external payment gateways.

Bold provides several other non-OpenAPI specifications, which outline the requests and responses of custom interfaces between a client and Bold:

  • Secure Payments Interface API — The interface that a customer uses to input their payment information and add the payment method to an order. The SPI 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.
  • External Payment Gateway Connector API and External Payment Gateway Actions and Events — The interfaces that Bold uses to communicate with an external payment gateway that is not already officially supported by Bold.

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 Bold Cashier API.

Extending Bold Checkout

You can use the Bold Checkout APIs to change and extend Checkout using integrations, external payment gateways, or platform connectors. Refer to Extend Bold Checkout for more information about the various ways that you can integrate different technologies into Bold Checkout.

Getting started

Ready to jump in? The Checkout Getting Started page gives you everything you need to know to begin using Bold APIs.