HI, PLEASE HOW MANY RECORDS DOES SAP ByDesign ACCEPT AT A TIME FROM AN API INTEGRATION.
I don't think there is such limitation defined and infact when huge number of documents are to be uploaded we recommend you to use Webservices(API,B2B etc). For example you can try 1000 at once( others in this forum may comment on this number)
The limitation we have in ByDesign is with number of items in a document that is given in below KBA
2956449 - Limitation on Number of Items in ByDesign Documents