Issue with /users/by-external route: The /users/by-external route does not support external_id values containing periods (.). This is a known issue in Rails, as discussed in this Stack Overflow thread.
Pull Request and Discussion: A pull request was submitted to address this issue, but the progress is uncertain. A related discussion about usernames with periods is also referenced.
Route Usage Clarification: The correct URL for the /users/by-external route is mydiscoursesite.com/users/by-external/1.json, but it’s unclear if mydiscoursesite.com/users/by-external/1 should work, where 1 is the external id from the SSO user table.
I noticed that the API includes a by-external route, which seems to allow you to get user data by the SSO external id, which is great. Unfortunately, it doesn’t seem to work with external_ids that have periods in them.