Where to store data using bloackstack and API

#1

Hi everyone, ssuming am building a post and Commenting.
I know that I will authenticate users using blockstack.

Here is my 2 questions.

1.) Where do I store and Retrieve the Chat messages, Post, comments etc.
Do Blockstack have a storage or Retrieving API or do I have to store them in my own site database.

2.) Does BlockStack has Restful API or some sort of SDK(Eg. php sdk or any) that one can leverage in the application.

This is urgent. Thanks