Universal Containers (UC) wants to build a custom mobile app for their field reps to...

The OAuth 2.0 user-agent flow and the OAuth 2.0 web server flow are both suitable for building a custom mobile app that can access Salesforce data without prompting the user to log in again1. Both ofthese flows use a refresh token that can be used to obtain a new access token when the previous one expires2. The user-agent flow uses theCanvas JavaScript SDK to obtain an OAuth token by using the login function in the SDK2. The web server flow redirects the user to the Salesforce OAuth authorizationendpoint and then obtains an OAuth access token by making a POST request to the Salesforce OAuth token endpoint2. The mobile agent flow and the SAML assertion flow are not valid OAuth flows for Salesforce3.