> For the complete documentation index, see [llms.txt](https://docs.parqex.com/-MUyxAVrX9S4wky8UoX6/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.parqex.com/-MUyxAVrX9S4wky8UoX6/oauth/overview.md).

# Overview

### ParqEx API Uses OAuth

All requests to the ParqEx service are governed by OAuth 2.0 ([quick primer](https://www.digitalocean.com/community/tutorials/an-introduction-to-oauth-2)) and follow the standard authorization-access token flow.

The ParqEx implementation closely follows [RFC 6749](https://tools.ietf.org/html/rfc6749).

### OAuth Flow Overview

When a user attempts to authorize their ParqEx account from your application, the following happens:

1. Your app generates the Authorization URL and displays the ParqEx login form to the user (see Step 1)
2. ParqEx attempts to authenticate the supplied credentials, and if successful, the user is asked to authorize access to their ParqEx account.
3. When the user authorizes access, an `authorization_code` is sent back to your app via a `GET` request (see Step 2)
4. Next, your app uses the `authorization_code` to request an `access_token` and `refresh_token` (see Step 3) 
5. Once you have an `access_token`, you can call the ParqEx API on the user's behalf (see Step 4)