Trello REST API POST permissions broken?

Hi people,

I can use the API project key and user token to view cards in trello REST API. Up until recently, I could also POST files onto those trello cards as attachments using the REST API. All of a sudden, now I can’t POST. Is the API partially broken at the moment or has something changed with API access?

The error I now receive (in myJson.response) is:

<Response [404]>

and in the myJson.text:

<!DOCTYPE html>
<html lang="en">
<meta charset="utf-8">
<pre>Cannot POST //1/cards/{card ID deleted}/attachments</pre>

I recreated my token and ensured it was marked for read and write permissions. From the 404 error, it appears to be a permissions issue, but the card being written to is newly created and using the same account tied to that token.

Any other ideas?




Here is my python function:

def addCardAttachment(trelloKey, trelloToken, filePath, cardId):
  import requests
  import json

  url = f"{cardId}/attachments"

  headers = {
    "Accept": "application/json"

  query = {
    'key' : trelloKey,
    'token' : trelloToken,

  files = {
    'file': open(filePath, 'rb'),

  response = requests.request(

  myJson = json.loads(response.text)
  return myJson

Based on that error, it looks like you’re trying to POST to //1/cards/ instead of /1/cards/. Does updating that make a difference?

@bentley Brilliant! I feel really stupid now. I’m not sure when that extra / crept in, but in the hours of trying to get this to work, I overlooked the obvious. Thanks very much!