> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sezzle.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

* Sezzle supports individually-authorized transactions for single purchases, with the latest version enabling customer tokenization for future transactions.
* Integration options include:
  * Direct API integration
  * Lightweight JavaScript SDK
  * Integrations with popular eCommerce platforms
* [Contact the Sezzle team](https://merchant-help.sezzle.com/hc/en-us/requests/new) for API-related questions.
* An approved Sezzle account is required to start integration; [sign up](https://dashboard.sezzle.com/merchant/signup) if you don’t have one.

<Warning>
  Assume that all API methods require an [Authorization bearer token](./core/authentication/postauthentication#authenticated-call-http-header).
</Warning>

## Direct Integration Quick Start

1. Use API keys to obtain an [authentication token](./core/authentication/postauthentication)
2. [Create a session](./core/sessions/postv2session) with an [order object](./core/sessions/postv2session#body-order)
3. Redirect user to Sezzle checkout URL
4. User completes Sezzle checkout
5. Sezzle redirects user back to [merchant complete URL](./core/sessions/postv2session#body-complete-url)
6. Manage the order with the [Order API](./core/orders/getv2order)

## Open API Specification

* The [OpenAPI Specification (OAS)](https://swagger.io/specification/) offers a standard, language-independent interface for RESTful APIs, allowing humans and machines to understand service capabilities without source code, documentation, or network traffic analysis.
* Access the [Sezzle v2 OpenAPI Specification](https://gateway.sezzle.com/v2api.yaml) for integration details.
* Import the Sezzle v2 OpenAPI Specification into the [Swagger Editor](https://editor.swagger.io/?url=https://gateway.sezzle.com/v2api.yaml) to generate a Sezzle client in multiple programming languages.
* For languages unsupported by Swagger, use [OpenAPI Generator](https://openapi-generator.tech/) as an alternative tool.