> ## Documentation Index
> Fetch the complete documentation index at: https://pleo-preview.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

## What is OAuth?

**OAuth 2.0**, or simply **OAuth**, is an industry standard for secured authorisation of web applications, allowing them to request access to user-owned resources from external resource providers, without asking users for their access credentials, such as passwords.

A few important characteristics of OAuth 2.0:

* In order to grant access, OAuth does not request for users' credentials.
* OAuth 2.0 also restricts actions — it keeps a check on what an external website/application performs on the resources hosted on other websites/applications.

## Roles

OAuth is a standard designed for access delegation. This includes the following four roles participating in the OAuth protocol (explained here in the context of integrating with Pleo):

* **Resource owner**: Pleo's customer - a company or an organisation (multi-entity set up) that owns a number of protected resources, such as accounting data, list of employees, etc.

* **Resource server**: Pleo APIs provides access to the protected resources.

* **Client** : Third-party applications that the Developer Partner wants to integrate with Pleo.

* **Authorisation server**: Pleo provides an OAuth implementation that fulfils the following:

  * Allows clients to request access to resource servers.
  * Helps resources owners to grant access to clients.

## Use of OAuth in Pleo

In Pleo, we provide an implementation of an OAuth authorisation server to help you with the following:

* Integrate third-part applications with Pleo using OAuth as the authorisation method.

* Use OAuth to access the Pleo APIs.

## How to use OAuth?

In order to integrate your application with Pleo using OAuth, you must perform the following:

1. [Register your application](https://pleo-preview.mintlify.site/docs/oauth-client-registration.md) and receive OAuth client credentials - client identifier and client secret.
2. [Integrate an OAuth client library](https://pleo-preview.mintlify.site/docs/implementing-the-oauth-client) in your application.
3. [Configure your OAuth client](https://pleo-preview.mintlify.site/docs/client-configuration.md) to work with Pleo's authorisation server.

After completing these steps, users of your application could successfully and securely transition data from Pleo.


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