Running into a wall with the Digital First Omnichannel API for custom messaging. We’re trying to allow customers to upload support docs via our web widget. We are using the API to send messages.
The payload structure matches the spec:
{
"media": [
{
"filename": "manual.pdf",
"mimeType": "application/pdf",
"content": "BASE64_STRING_HERE"
}
]
}
Small text files go through fine. But as soon as the base64 string hits around 2.5MB (which is a tiny PDF), the server throws a 413 Payload Too Large. The documentation explicitly states the limit is 5MB for application/pdf.
I’ve checked our Nginx config on the origin server, client_max_body_size is set to 10m. We’re not hitting a network timeout. It feels like the DFO API has a hidden or stricter limit than advertised, or maybe the base64 encoding overhead is being counted against the limit before decoding?
Has anyone pushed a 3MB+ file through this specific endpoint? Or is there a chunking mechanism I’m missing?