Get total count of Custom variables

How to get the total count of custom variables using Piwik API?

Hi,
I am not sure about what do you mean by total count of custom variables.
The number of slots a Piwik installation has already used?
The sum of the amount of the different custom variables values?
I am not 100% familiar with the Piwik API, but I would probably play with: https://developer.piwik.org/api-reference/reporting-api#CustomVariables and add extra parameters to just export the data I want.
Just precise your demand and I will do my best to help.

Hi,

Thanks for your reply. I want to get total number of custom variable values which is useful for pagination purpose. Piwik report API will limited to fetch 100 rows. So that I need to implement pagination in my application.

Are you sure? You may want to look into the filter_limit parameter:
https://developer.piwik.org/api-reference/reporting-api