Benzene

Correlation Ids

Cross-service correlation is handled by automatic W3C traceparent propagation (UseW3CTraceContext()), which continues a distributed trace from the incoming traceparent/tracestate headers on every transport — see the migration guide.

What remains

ICorrelationId and its log-scope enrichment are still available. WithCorrelationId() attaches a correlationId value to the logging scope (via ILogger.BeginScope):

.UseLogResult(x => x.WithCorrelationId());

With nothing populating it, ICorrelationId self-generates a GUID per scope — useful as a per-invocation marker in logs. To populate it from a custom source (e.g. a partner's proprietary header), register AddCorrelationId() and call ICorrelationId.Set(...) from your own middleware:

app.Use("PartnerCorrelation", resolver => async (context, next) =>
{
    var headers = resolver.GetService<IMessageHeadersGetter<MyContext>>();
    resolver.GetService<ICorrelationId>().Set(headers.GetHeader(context, "x-partner-request-id"));
    await next();
});

Outbound clients can still forward the value: .UseCorrelationId() on an outbound route pipeline (see Clients — Outbound middleware) stamps the current ICorrelationId onto the outgoing request's x-correlation-id header.

See Also