First call from App1 to App2 is missing

[sundarv85]

I'm currently testing Coroot Node Agent with a basic Node.js setup, and I'm not seeing the first call from App1 to App2 being captured. PS: I am trying not to use OpenTelemetry setup as of now. An example would be:

I have three separate Node.js applications, all are running locally:

*App1 → port 3000
*App2 → port 3001
*App3 → port 3002

App1 calls App2, which in turn calls App3. Example flow:
App1 → App2 → App3

Yet, only App2 → App3 trace is visible in Coroot, and the call from App1 to App2 is NOT captured.

What might be the reason for this missing trace? Is there any header propagation or manual instrumentation steps needed in Node.js apps to get full trace visibility?

Environment Info:
Node.js version: v23.3.0
Coroot Node Agent version: 1.23.22
OS: Ubuntu

Please let me know what I may be missing or if it will work ONLY with explicit OpenTelemetry instrumentation for this case. This is because, a vendor which we are using already supports this auto instrumentation from App1 to App2 also without OTEL. Hence the question here.

[def]

eBPF-based spans have their limitations. Coroot is an observer-only tool and doesn’t inject headers into requests, so while it can capture a span from app1 to app2 and another from app2 to app3, it can’t reliably connect them into a single trace.