---
title: "Customize"
slug: "customize"
updated: 2026-10-27T18:42:23Z
published: 2026-10-27T18:42:23Z
canonical: "docs.onespan.com/customize"
---

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

# Customize

This section provides instructions for extending beyond the configuration options described in the **Operate** section to customize almost every aspect of the S3 Suite:

- The App SDKs allow you to customize or completely replace the user interface that they display in your application.
- Customize the provided Nok Nok Passport App to easily enable out-of-band authentication for end users.
- Customize the behavior of the API Server by implementing plugins for session tokens, transactions, and external authentication.
- The Authentication Server exposes an interface that allows integration with an external cryptographic service provider and/or an external secrets vault.
- The S3 Suite includes an Android and an iOS authenticator SDK that allow you to create authenticator specific modules (ASMs).