What is the api function call to access NXT's Data Cloud feature? If I hosted a few files on the NXT's Decentralized Data Straoge Cloud, how can I access those files via an API?
You can download your file using this API

localhost:7876/nxt?requestType=downloadTaggedData&amp;transaction=nnnn&amp;retrieve=true

where nnnn = Txid of your uploaded file

You can search txid for all your uploads using requestType=getAccountTaggedData&amp;account=NXT-XXXX-XXXX-XXXX-XXXXX

where NXT-XXXX-XXXX-XXXX-XXXXX is your account number

If your localhost is not hosting prunable data, retrieve from a public node which is a Service Provider (with PE &amp; AI listed under Services) in your peer's list.



Examples:

Retrieve all Txids of all uploads for account NXT-TBAJ-LVLX-YCWY-5FRLD
23.94.134.161:7876/nxt?requestType=getAccountTaggedData&amp;account=NXT-TBAJ-LVLX-YCWY-5FRLD

Download PGP key of Core Dev
http://23.94.134.161:7876/nxt?requestType=downloadTaggedData&amp;transaction=633908232195174623&amp;retrieve=true

Full set of API for Nxt Data Cloud can be found at
localhost:7876/test?requestTag=DATA