---
title: "Create a custom API Server plugin"
slug: "s3suite94-create-a-custom-api-server-plugin"
updated: 2026-10-27T18:42:23Z
published: 2026-10-27T18:42:23Z
canonical: "docs.onespan.com/s3suite94-create-a-custom-api-server-plugin"
---

> ## 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.

# Create a custom API Server plugin

# Introduction

When you create a custom API Server plugin, you implement an interface defined by Nok Nok. First read the instructions for how to create a [Session Plugin](/dpoa/docs/s3suite94-create-a-session-plugin), a [Policy Plugin](/dpoa/docs/s3suite94-create-a-policy-plugin), a [Transaction Plugin](/dpoa/docs/s3suite94-create-a-transaction-plugin), or an [External Authentication Plugin](/dpoa/docs/s3suite94-create-an-external-authentication-plugin). If you need more information about these interfaces, request the Nok Nok API Server SDK from [Nok Nok customer support](mailto:support@onespan.com).