Welcome to the Sezzle OpenAPI reference section, where you can find details on each of the Sezzle API endpoints.

Here are some of the features of this upgraded reference:

  • An interactive Try It feature enabling you to test API calls to the Sezzle sandbox.

  • Example code demonstrating how to make API requests in a variety of languages including Python, Node, and many others.


To learn about these and other features, follow the tutorial below.

Note: This guide is intended for merchants who are using the Sezzle API v2, which is the latest version. If you need to clarify which version your developers are using or have any other questions regarding our API please reach out to our team here: Submit Merchant Help Request

View the Sezzle OpenAPI v2 specification.

API Endpoints

To view documentation for Sezzle API endpoints, do one of the following:

  • Expand the categories in the menu at the left and select an endpoint name, as shown below.
  • Click the field labeled JUMP TO and select from the popup list of endpoints, or type words into the Filter field to narrow the choices.

To try out API calls you need:

  • secret and public keys that you can obtain from your Sezzle Merchant dashboard
  • a token that you generate using the keys described above

See the Integration Guide and the tutorial below for more details.

Tutorial: Making your first "Try It" call

This walk-through demonstrates how to use the interactive Try It features of this API reference section. Note : This is not a demonstration of how your company will use the API normally but only how you can try out making requests to API endpoints while reading the documentation.

To demonstrate, we'll get your authentication token, and use this to create a session.

Prerequisite: A Sezzle merchant account

  1. Access your Sezzle Merchant Dashboard

  2. Select API Key

  3. Locate your private key and public key (scroll to the right to see your public key if necessary), and as an option copy both of these to a note pad for convenience.

  4. Go to Get a Bearer Authentication Token in this API reference.

  5. Paste the private and public keys into the fields labeled private_key and public_key under BODY PARAMS

  1. Under URL click Base URL to access the menu and select *https://gateway.sezzle.com/v2.

Note that some of the images in this tutorial might show a different server URL. For this tutorial, we're making calls to your Merchant Dashboard just to try out the features of this interactive API documentation.

f you want to use the sandbox environment to develop and test API workflows, you can use the dummy information that we provide as described in the guide section here.

  1. Click Try It on the bottom right.
  2. From the RESPONSE box, copy the token.
  1. Go to Get a list of customers in this API reference.

  2. Under AUTHENTICATION in the Header field, enter Bearer followed by a space and then your token, as shown here.

  1. Click Try It to make the request. A successful response will be similar to the following:
    "uuid": "2cb73f3e-d5f0-4cb3-8654-de1796e7caf0",
    "links": [
        "href": "https://sandbox.gateway.sezzle.com/v2/customer/2cb73f3e-d5f0-4cb3-8654-de1796e7caf0",
        "rel": "self",
        "method": "GET"
        "href": "https://sandbox.gateway.sezzle.com/v2/customer/2cb73f3e-d5f0-4cb3-8654-de1796e7caf0",
        "rel": "self",
        "method": "DELETE"
        "href": "https://sandbox.gateway.sezzle.com/v2/customer/2cb73f3e-d5f0-4cb3-8654-de1796e7caf0/preapprove",
        "rel": "preapprove",
        "method": "POST"
        "href": "https://sandbox.gateway.sezzle.com/v2/customer/2cb73f3e-d5f0-4cb3-8654-de1796e7caf0/order",
        "rel": "order",
        "method": "POST"
    "expiration": "2022-07-23T21:17:33Z"

This response contains only one customer, whose ID is displayed in the line that starts with uuid. In most cases, multiple customers will be listed. With this customer ID, you can make other API calls, which are beyond the scope of this tutorial, provided to give you the experience of using Try It , a feature designed to test individual API requests directly from this API reference documentation, not to step through an entire workflow.

  1. To explore an additional feature of this API reference documentation, under LANGUAGE click the button labeled Python.

In the REQUEST box that previously showed the default Curl code for your request, the request code in Python now appears.

  1. Click the the vertical ellipsis (kebab) button at the right of the language buttons to see more language choices, as shown in the first image on this page. Try clicking some of the other languages to see examples.