According to the Valence Docs,
Valence Learning Framework API calls are all made in isolation, by a known application, and by a known LMS user.
If I want to build an application that has admin access, I'm guessing that I would have to make a "service account" that has admin access, and have my application use the API as that user.
How would I go about obtaining a userId and userKey for users that aren't real people, and only exist for the application to connect to the valence API?
Once you create a Service Account, you need to manually harvest the user tokens using a utility such as the API Test Tool (https://apitesttool.desire2learnvalence.com/) to authenticate with your LMS. You then need to store those keys securely, and configure your LMS to ensure the user tokens are long-lived. Many systems have a token timeout of 30 days, but when a headless integration is in place like the one you're proposing, it's often a good idea to make the timeout infinite. You can contact Desire2Learn Support to verify the timeout value for the user tokens.
There's a similar question that addresses this issue as well: Authenticaton Method for Desire2Learn REST API vs SOAP.
来源：https://stackoverflow.com/questions/21712396/consuming-the-valence-api-as-an-application