Is there any rest v10 API to retrieve available modules in v10 REST API version?

Hi I just created a custom field in in database(in user table, i don't know it is good way or not), now i want to get the custom field value using REST api,all value are retrieving except my custom field. Below is my rest api params $get_entries_parameters…

When upload document for certain account, the documents_accounts table stores both account id and document id. When upload the file from REST api, need to store the account_id and document_id in document_accounts table, but i can't store those values…