API access must be enabled for your Cirrus Insight users to connect to your Salesforce org.
Note: This setting is only available if you have the Enterprise Edition of Salesforce.
Your Salesforce administrator controls your profile and permission set.
To access the API (to issue calls and receive the call results), your user must be granted the “API Enabled” permission.
Client applications such as Cirrus Insight can query or update only those objects and fields to which they have access via your permission set.
To edit your profile, your admin will need to go to Setup | Manage Users | Profiles in the Salesforce user interface to grant the "API Enabled" permission.