Missing W3C headers (traceparent/tracestate) on Cross-Origin requests (Auto-injected RUM)

jocampom — Mon, 18 May 2026 16:07:23 GMT

Hello Community,

I am running a Proof of Concept (PoC) on a web application using the auto-injected RUM agent (created via Experience Vitals / Gen3). Our main goal is to link RUM with our distributed system by standardizing the W3C Trace Context.

The Scenario:

Frontend Domain: https://mywebsite.com
Backend Domain: https://mybackend.dev (Cross-Origin)

Current Configuration: Following the official documentation

https://docs.dynatrace.com/docs/observe/application-observability/distributed-tracing/tracking-transactions

I have globally enabled W3C propagation under Settings > Collect and capture > General monitoring settings > OneAgent features, by turning on "Send W3C Trace Context HTTP headers". Additionally, I have configured the correlation rules for Cross-Origin XHR actions using the correct regular expression for my backend's domain.

Observed Behavior (The Issue): Auto-injection is working, and the RUM agent intercepts requests correctly. However, when making a request to our backend, the agent only injects the proprietary x-dtc header. The standard traceparent and tracestate headers are missing entirely.

When inspecting the script's configuration string in the browser (data-dtconfig), I noticed that the tracking property still outputs tp=500,50,0 (W3C disabled for frontend), despite having the OneAgent feature enabled globally on the tenant.

My questions:

Given that the main frontend domain is completely different from the backend domain, is there a hidden setting or specific menu in Gen3 that I need to enable to force the auto-injected RUM agent to emit traceparent on CORS calls to third parties?
If this limitation of only injecting x-dtc for CORS is expected behavior (by design) for the current agent, would you recommend that we standardize this W3C injection manually from our frontend code to the backend, rather than trying to force the agent to handle it?

Looking forward to your insights. Thank you.

topic Missing W3C headers (traceparent/tracestate) on Cross-Origin requests (Auto-injected RUM) in Real User Monitoring

Missing W3C headers (traceparent/tracestate) on Cross-Origin requests (Auto-injected RUM)