API Docs: File Upload API

Hi @gleblanc1783,

Your code looks good, except you've got a small typo when preparing the file to attach to the request.

    files = {"file": open(file_, 'rb'), "filename": file_} # incorrect

This should have refer to the file you're uploading as "files" since this API route can receive multiple files at once.

    files = {"files": open(file_, 'rb'), "filename": file_} # correct

You'll then get back a filename that you can attach to a Post object when making sending a message.

Also, regarding the Slack compatibility, that's only for our Webhooks and Slash commands. The REST api doesn't try to be compatible with Slack.