How can I retrieve required fields from a module using REST v10 API ?

Do you need to know the 'required' fields or do you need to know all the fields? Please keep in mind that while you can get a list of fields for a specific module you should also know what is used and what types of fields Sugar has to offer. 

The endpoint you are looking for is: 
sugarinstance/.../metadata

This will return a list of all modules with their fields. Look for 'modules' -> 'modulename' -> fields in the returned json. This should give you a hint. 

Hi Sino, 

Just to add to Jeroen's feedback you can check some tips on how to use the metadata endpoint here:

sugarclub.sugarcrm.com/.../3-tips-for-using-the-sugar-metadata-api

Jeroen Somhorst I am looking for all the 'required' fields of a module

modules -> Leads-> required fields.

Hi Sino,

as answered by Andre Serrazina, metadata entrpoint will provided you all the required informations.