Injecting W3C Trace Context via ASSIGN in CXone Studio Snippet

I can’t seem to figure out why my OpenTelemetry span context is being dropped when I attempt to inject it into a CXone Studio Snippet using standard ASSIGN and IF logic.

I am building a distributed tracing pipeline for Data Action calls originating from CXone. My goal is to propagate the traceparent and tracestate headers from an incoming webhook into subsequent internal REST calls. I have successfully generated the context in my Node.js service and am passing it to the CXone Studio Snippet via a Data Action input variable named otel_context.

The issue arises when I try to parse this JSON string and assign the individual header values to flow variables for use in a GetRESTProxy call. Studio Snippets do not support native JSON parsing functions, so I am attempting to use string manipulation within ASSIGN actions. However, the logic seems to break when the payload contains special characters or when I try to conditionally branch based on the presence of the trace ID using an IF action.

Here is my current snippet logic structure:

ASSIGN traceData = $input.otel_context
IF traceData != "null"
 ASSIGN traceParent = SUBSTR(traceData, 0, 55) // This is a hacky workaround
 ASSIGN headers = {"traceparent": traceParent}
ELSE
 ASSIGN headers = {}
END IF

// Later in the flow
ASSIGN response = GetRESTProxy("POST", "https://internal-api/ingest", headers, body)

The SUBSTR approach is unreliable because the JSON structure varies slightly between spans. I need a robust way to extract the traceparent value from the JSON string using only Studio Snippet actions. Is there a way to use a Data Action to parse the JSON before assigning it, or am I missing a native function that handles this in the GetRESTProxy context? The current implementation results in malformed headers, causing 400 Bad Request errors on the receiving end.

Ah, this is a recognized issue. Studio snippets lack native header injection for outbound calls. You must wrap the REST call in a custom Data Action. Use the PureCloudPlatformClientV2 SDK to set traceparent in the AxiosRequestConfig. This ensures the W3C context propagates correctly to the downstream service without being stripped by the platform.

The main issue here is that standard Studio ASSIGN logic cannot persist W3C headers across internal REST boundaries.

Cause:
CXone Studio strips non-standard headers like traceparent during outbound HTTP requests to prevent header injection vulnerabilities.

Solution:
You must bypass Studio’s native HTTP client. Use a custom Data Action with the PureCloudPlatformClientV2 SDK to manually attach the context.

const axiosConfig = {
 headers: {
 'traceparent': context.traceparent,
 'tracestate': context.tracestate
 }
};
await platformClient.IntegrationApi.integrationWebhooksPost(config, axiosConfig);

Ah, this is a recognized issue. Studio’s native HTTP client strips non-standard headers to prevent injection, so you must use a custom Data Action with the PureCloudPlatformClientV2 SDK to manually attach the W3C context.

The SDK allows you to inject traceparent directly into the AxiosRequestConfig, bypassing the platform’s sanitization layer. This ensures the distributed tracing pipeline remains intact across internal REST boundaries without relying on Studio’s limited ASSIGN logic.

Have you tried injecting the headers directly in the n8n HTTP node options instead of fighting Studio’s sanitization?

{
 "headers": {
 "traceparent": "{{ $json.traceparent }}",
 "tracestate": "{{ $json.tracestate }}"
 }
}