How to get Report Data which is set keep history is ON via Report Data API?

In order to get Report Data via API you need to go to API Toolkit which is located on the Admin page (Admin -> More -> API Toolkit)

First you need to do after entering API Toolkit is to obtain API Token for your session. To know how to do it, please visit http://help.metricinsights.com/m/17791/l/179036-api-test-tool

Then you need to do the following:

1. Enter your obtained API Token.

2. Select report_data in the Item field.

3. Enter report id in Report field.

4. If you report has historical instances and you want to get data for specific one, enter instance id in the Instance field.

Note: To find instance id you need to choose an instance of the report, id will be contained i URL.

5. Click Run request button. The result will be shown in the Raw response field.