How to encode attachments for use via Trello web API [closed]

Question

The file parameter documentation for the POST /1/cards/[card id or shortlink]/attachments API call does not specify how the file should be encoded. For "Valid Values" it simply says "A file". I was wondering if anyone has a working example of how to get files into Trello cards using the API.

Answer 1

You should be able to add an attachment using the multipart/form-data content type:

<form action="https://api.trello.com/1/cards/REPLACE_WITH_CARD_ID/attachments"
      method="POST" enctype="multipart/form-data">
   <input type="hidden" name="key" value="REPLACE_WITH_YOUR_KEY" />
   <input type="hidden" name="token" value="REPLACE_WITH_YOUR_WRITE_TOKEN" />
   <input type="file" name="file">
   <input type="submit" value="Upload">
</form>

(You don't necessarily have to be POSTing from a webpage, but that's an easy example)