The vividLMS API has a rate limit on the number of calls you can make.
The Client Rate Limit
You can make 200 API requests per minute for each IP address that has authorized access to LMS data. This rate limit is applied when you make an API request using your application's admin id and token.
Hitting the Rate Limit
Your application will receive a HTTP 403 FORBIDDEN response from the vividLMS API when a request is not fulfilled due to reaching the rate limit. You will need to contact firstname.lastname@example.org to have your rate limit reset and begin making calls again.