Suppose I have a page, http://foo.com/bar. Is it possible to use the Graph API to let a use add a comment for that url to avoid the need to host the Facebook comment plugin?
I have a case where I want to let user sign in with Facebook but create my own comment UI. I know I can read all the comments with a call like this:
https://graph.facebook.com/comments?id=http://imdb.com
(assuming the link I care about is http://imdb.com).
However, I can't find a documented way to allow me to write a comment for a user given a specific access_token.
No, this is not possible. Previously there was a loophole to POST to the /comments endpoint with a messages parameter, but this is now closed. You must use the comments plugin to add comments.