Question

Is it possible to post on a friend’s wall from an external source (a different website)?

I have a platform that manages birthdays, and I want the users to post a birthday wish/card on their friends wall without going into Facebook.

Is that possible?

Answer 1

Sure. You need to get the publish_stream permission which according to the official docs:

Enables your app to post content, comments, and likes to a user’s
stream and to the streams of the user’s friends. With this permission,
you can publish content to a user’s feed at any time, without
requiring offline_access. However, please note that Facebook
recommends a user-initiated sharing model.
(http://developers.facebook.com/docs/reference/api/permissions/)

You would then use whatever SDK your using (php/js/python/etc) to publish to https://graph.facebook.com/profile_id/feed

parameters you could use in addition

{"name": "Link name"
 "link": "http://www.example.com/",
 "caption": "{*actor*} posted a new review",
 "description": "This is a longer description of the attachment",
 "picture": "http://www.example.com/thumbnail.jpg"}