Cloud APIs & SDKs for Microsoft Excel & OpenOffice Calc digital signature. Spreadsheets digital signature by the Cells Cloud API. SDK support kinds of development languages. They include Android, C#, Go, Java, NodeJS, Perl, PHP, Python, Ruby, and swift....Client Secret, Base URL & API version Call CellsWorkbookPostDig method...stream System Requirements go version go1.13.0 or newer...