Download report(Keyword performance) for all accounts and campaigns (single report) using the Adwords API

I am new to Adwords and I am trying to figure out if there is a way to download report(Keyword performance) for all accounts and campaigns (single report) using the Adwords API. I am able to get the report for individual ClientCustomerIds, but I want the report at the level of all accounts and

Download report using API for all accounts and Campaigns

I am new to Adwords and I am trying to figure out if there is a way to download report(Keyword performance) for all accounts and campaigns (single report) using the Adwords API. I am able to get the report for individual ClientCustomerIds, but I want it at the level of all accounts and campaign