Salesforce: How do I enable the API?

To use the API, your organization must be on one of the following 4 editions (the API is enabled by default):
Enterprise Edition
Unlimited Edition
Developer Edition
Performance Edition

Editions with no API Access:
Contact Edition
Group Edition
Professional Edition
Spark Edition
You may reach out to your account executive for assistance about what option you can have to have access to API.
To contact Salesforce to make an enquiry:
Log in to Salesforce, then go to the Help and Training page.
At the bottom of the page, click Contact Support.
Select your support topic and category.
See if there’s an existing topic that relates to your issue.
If you don’t find the solution to your problem, click Create a Case.
Enter case details and click Submit.