The DigitalOcean API allows you to manage resources in the DigitalOcean cloud in a programmatic way using conventional HTTP requests. All of the functionality available in the DigitalOcean Control Panel is also available through the API.
See the API documentation on Droplets for more information.
doctl is a command-line interface for the DigitalOcean API and supports many of the same actions.
doctl documentation on Droplets for more information.