CXone Studio GetRESTProxy returning null response body

NICE CXone API & Integrations
1

Hey everyone, I’ve run into a really strange issue with the GetRESTProxy action in Studio when trying to parse a JSON response.

  • I am making a POST request to a custom internal endpoint that returns a simple JSON object with a nested status field.
  • The action succeeds with a 200 OK, but when I try to ASSIGN the response body to a string variable, it comes back as null.
  • I have verified the Content-Type header is set to application/json and the endpoint works fine in Postman.
  • Here is the snippet configuration I am using:
Action: GetRESTProxy
Method: POST
URL: https://internal.api.example.com/status
Headers: Content-Type: application/json
Body: {"check": true}
  • Why is the response body null even though the HTTP status is 200?
2 Likes
2

The quickest way to resolve this is to explicitly convert the response body to text within your Studio data mapping, as CXone sometimes struggles with complex JSON.

ToString(GetRESTProxy.ResponseBody)

Studio can occasionally fail to automatically deserialize nested JSON structures, leading to a null value despite a successful 200 OK response.

3

Yep, this is a known issue… especially with high-volume interactions where the GetRESTProxy action might return a raw buffer instead of a parsed object. Casting to a string is a quick fix, but often leaves escaped quotes that break downstream JSON parsing. For complex payloads in my monitoring integrations, I usually bypass the Studio proxy and use an outbound webhook to trigger a serverless function instead. This lets us handle the payload and explicitly parse the JSON with retries.

If you must stay in Studio, ensure your internal endpoint returns a simple JSON string without extra whitespace, as the deserializer is strict. Test by logging the raw response body to a debug variable before the assignment. If it looks like [object Object], the issue is likely the response header Content-Type. I recommend adding a Log to Console action to log the full response headers to verify it’s exactly application/json; charset=utf-8. Also, check your endpoint’s CORS settings.

4

The core issue likely stems from how CXone Studio’s GetRESTProxy handles the underlying HTTP transport. It’s a HTTP/1.1 wrapper that buffers responses. If your endpoint uses persistent connections or chunked transfer encoding, the proxy might time out or return an incomplete buffer before receiving the full JSON payload. Assigning to a string is a workaround, masking a potential race condition or incomplete read.

Inspect the response headers in the Studio trace; look specifically for Transfer-Encoding. If it’s chunked, Studio often struggles to aggregate the response correctly.

Consider using the Event Stream API instead, which handles streaming JSON natively.

// Example of subscribing to an Event Stream
const eventStream = new EventSource('https://events.cxone.com/stream'); // Replace with your stream URL

eventStream.onmessage = (event) => {
 const msg = JSON.parse(event.data);
 console.log(msg);
};

eventStream.onerror = (error) => {
 console.error('Event Stream Error:', error);
};

Avoid HTTP proxies for streaming data; they’re inherently fragile. Always be mindful of CXone API rate limits and security best practices when implementing custom integrations.

2 Likes
5

The problem is that studio’s getrestproxy buffers the stream, so chunked responses often result in null bodies. check the response headers for transfer-encoding: chunked. if present, switch to a webhook pattern instead.