Sending Feed Events with Attachments or Images

When sending feed events where the card includes an attachment section or an image section, it is possible to upload a document or image in the call to the Send Feed Event Endpoint and use it in the card.

Firstly, rather than calling the Send Feed Event Endpoint with a JSON body as per the documentation, you should call the endpoint with a Multipart form body. Simply put all the documented fields as key/value pairs in the multipart form.

Then, to send a document or image, add the document or image under the key attachment. You should also send an attachment id under the key attachment_id. Attachment ids must be in the form a-<UUID>. Generate sample UUIDs here. For example a-ca6eb2fd-1327-443f-bbec-5f0856ba25ac is a valid attachment id.

Because you're sending the atttachment id that will be assigned to the attachment you're uploading, you can use it in CardKit seciton fields such as image_url or download_url by specifying the value as https://api.joinblink.com/file/<attachment_id>.

For example, if you're uploading an image in the attachment field on the Send Feed Event Endpoint with attachment_id set to a-ca6eb2fd-1327-443f-bbec-5f0856ba25ac. You could then use the image in the CardKit JSON you send in the body field as follows:

{  
   "sections":[  
      {  
         "type":"text",
         "value":"Here's a nice image"
      },
      {  
         "type":"image",
         "image_url":"https://api.joinblink.com/file/a-ca6eb2fd-1327-443f-bbec-5f0856ba25ac"
      }
   ]
}