You can integrate external systems with Workbooks using the Workbooks API. Using API keys allow external systems to access a specified Workbooks Database on the user's behalf, with all of their Capabilities and Permissions.

Creating an API Key in order to allow external systems to communicate with Workbooks removes the need for the external system to login using a username and password each time.

An API Key can be created by going to Start > Configuration > Email & Integration > API Keys > New API Key. 

Select a user using the dropdown picklist next to 'Access as User'. This determines which user the API Key will run as, with their Capabilities and Permissions. Give the API Key a name which you can use to easily identify what it is used for. It is also helpful to add a meaningful description 

Further to this, you can specify certain login restrictions, such as a range of dates for which the API Key is valid and one or more IP addresses from which the API Key can be used.  If you specify more than one IP address you should separate them using a comma. You can also restrict the API Key's Capabilities to a subset of those of the User which you have selected. If you do not, then the API Key will adopt the same Capabilities as specified in the "Access as User" field.

Click Save & Close. The API key will now appear in the grid on the right.