gistfile1.txt

POST to /api/post with the following json as the body of the document

{
    "assignment_id": null, ( or the assignment id )
    "contents": "this is the text contents of my post!"
}

POST to /api/media_objects as a form submit ( as we had been doing before )

media_type = audio|video|image
media_file = <file being uploaded>
post_id = <the post idea the media object is being assigned to>