API keys can be used to authenticate requests in Core while impersonating another user; however, note the following:
Impersonation can only be enabled by a member of Resolver Support at the time the key was created. Should you wish to enable impersonation, contact Resolver Support to create a new API key.
Any user can be impersonated, provided you've obtained their user ID and the user is active in the org the API key was created for.
Actions performed while impersonating using an API key are captured in the audit trail as "[API User's Name] impersonating [Impersonated User's Name]".
If a user is impersonated using an external system (integration), the Modified By property on an object will show "[API User's Name]", but would still be captured in the audit trail as "[API User's Name] impersonating [Impersonated User's Name]".
To impersonate a user with an API key, open a supported endpoint in Swagger, enter the API key in the x-api-key field and the ID of the user to be impersonated in the impersonate-user-id field. The user ID can be obtained from the address bar of your browser after navigating to the Edit User page for the user (e.g., 1732).
The Edit User page. The user ID is displayed in the address bar.