---
title: "Create a custom API server plugin"
slug: "dpo-api-server-plugins-creation"
updated: 2026-10-27T20:13:33Z
published: 2026-10-27T20:13:33Z
canonical: "docs.onespan.com/dpo-api-server-plugins-creation"
---

> ## 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 DigipassONE Authenticate. First read the instructions for how to create a [Session Plugin](/dpoa/docs/s3suite94-create-a-session-plugin-1), a [Policy Plugin](/dpoa/docs/s3suite94-create-a-policy-plugin-1), a [Transaction Plugin](/dpoa/docs/s3suite94-create-a-transaction-plugin-1), or an [External Authentication Plugin](/dpoa/docs/s3suite94-create-an-external-authentication-plugin-1). If you need more information about these interfaces, request the DigipassONE API Server SDK from [OneSpan customer support](mailto:support@onespan.com).

Formerly known as Digipass S3 Authentication Software. Enables passkeys, multi-factor authentication (MFA), hardware authenticators, one-time password (OTP).

Formerly known as Digipass S3.