The most basic way to use LevelUp is simply as a method of payment. In this scenario, the user flow is as follows:

Online:

1. User logs in or registers for your site’s account.
2. On the checkout screen, your site displays payment options and ability to add new ones.
3. User selects “Pay with LevelUp”.
4. You pass the user’s email as the login_hint to LevelUp’s OAuth Flow along with the requested permissions, such as: create_orders or read_user_orders.
5. User is redirected back to your redirect_uri with a one-time-use code param.
6. Use the code param to request an access_token (as part of the OAuth Flow).
7. Store access_token on user’s account in your system.

In-App:

1. User logs in or registers for your app’s account.
2. On the checkout screen, you display payment options and ability to add new ones.
3. User selects “Pay with LevelUp” and is deep-linked into the LevelUp application. The deep-link URL must be configured with the desired permissions.
4. LevelUp presents a dialog to the user explaining the permission request.
5. The user accepts or rejects it and is redirected back to your app with an access_token. That access_token can now be used to charge the user money, read their basic info, etc. The access_token LevelUp passes back both online and in-app can be stored on that users account for future usage, allowing the user to authenticate just one time.