Sezzle's current v2 API documentation is based on the OpenAPI Specification (OAS), a standard, programming language-agnostic interface for RESTful APIs. You can read more about OpenAPI here.

The Sezzle v1 API is based on the immediate predecessor to OpenAPI, called Swagger 2.0

You can find a useful interactive visual guide to the differences between Swagger 2.0 and OpenAPI 3.x here.

Access the raw OpenAPI and Swagger specifications as .yaml files

View the Sezzle v2 OpenAPI Specification.

View the Sezzle v1 Swagger specification