If you have different levels of permissions configured for users within your Salesforce application, those permissions will be inherited and remain unchanged through the OAuth flow as the Salesforce Sales Cloud element is integrated.
Salesforce has multiple types of accounts and editions. Only these allow you to use the API:
- Enterprise Edition
- Unlimited Edition
- Developer Edition
- Performance Edition
Visit https://help.salesforce.com/HTViewSolution?id=000005140&language=en_US for more information.