We are testing the Guest API for file attachments in web messaging. The documentation lists accepted MIME types but the size limit is vague. Sending a 5MB PDF to POST /api/v2/conversations/messages returns a 413 Request Entity Too Large immediately. The body is empty so it’s hard to debug. Here is the request payload structure we are using.
var message = new {
conversationId = “abc-123”,
to = new { new { id = “user-456”, type = “user” } },
type = “text”,
text = “Please see attached report.”,
attachments = new { new { name = “report.pdf”, mimeType = “application/pdf”, content = base64String } }
};
We tried reducing the file to 2MB and it worked. Is there a hard cap at 5MB for the Guest API or is it configurable on the org level? The .NET SDK doesn’t throw a specific exception for this, just the HTTP error. We need to know the exact threshold to implement client-side validation. The error happens before any business logic runs. It’s a generic Nginx or API gateway block. We don’t see any Genesys specific error codes in the response headers. Just 413. What is the actual limit? We are hitting this on every test run with files over 4.5MB. It’s consistent. We need a definitive answer. The docs say ‘large files’ which is not helpful for code. We can’t guess. Is it 5MB exactly? Or 10MB? The error is abrupt. No retry logic helps. We are stuck on this validation step.