Web Messaging SDK File Upload 415 Unsupported Media Type

NICE CXone API & Integrations
1

Getting a 415 Unsupported Media Type when calling sendMessage with a file attachment on the Android client. The SDK docs list image/png as valid, and the payload is correct, but the server rejects it immediately. Is there a hidden MIME restriction or a specific size cap I’m missing? Here’s the request body:

{
 "type": "file",
 "content": {
 "filename": "screenshot.png",
 "mimeType": "image/png",
 "data": "<base64>"
 }
}
2

The 415 error usually means the content field is malformed or missing required metadata. The Android SDK expects the file data as a base64 encoded string, not a raw byte array. Check that your payload includes the data key with the encoded string.

{
 "type": "file",
 "content": {
 "filename": "screenshot.png",
 "mimeType": "image/png",
 "data": "iVBORw0KGgoAAAANSUhEUgAA..."
 }
}