Open Messaging API rejecting structured payload

NICE CXone API & Integrations
1

Trying to send a quick reply card via the Open Messaging API but getting a 400 Bad Request.

The endpoint is https://api.mypurecloud.com/api/v2/conversations/messaging/messages.

Here is the JSON body I’m sending:

{
 "mediaType": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
 "content": {
 "type": "card",
 "title": "Options"
 }
}

The response says Invalid mediaType. Not sure what the correct value is for a card message. I’ve tried text/plain but that just sends raw text. Any ideas?

2

You’re hitting a type mismatch on mediaType. The Open Messaging API expects application/json for structured content like cards, not that Word doc MIME type. Also, the content object needs specific properties depending on the card type you’re trying to render.

Here’s what a valid quick reply card payload looks like in Node using the SDK or direct fetch:

const payload = {
 mediaType: "application/json",
 content: {
 type: "card",
 title: "Options",
 description: "Choose an option",
 quickReplies: [
 { title: "Option 1", type: "text", value: "opt1" },
 { title: "Option 2", type: "text", value: "opt2" }
 ]
 }
};

// Example using fetch
await fetch('https://api.mypurecloud.com/api/v2/conversations/messaging/messages', {
 method: 'POST',
 headers: {
 'Content-Type': 'application/json',
 'Authorization': `Bearer ${accessToken}`
 },
 body: JSON.stringify(payload)
});

The mediaType tells the engine how to parse the content. If you send a non-JSON mediaType with a JSON body, it rejects it immediately. Make sure your content object has the required fields for the card type you’re using.