more fixes based on PR comments

crates/brightstaff/src/handlers/llm.rs

@@ -42,12 +42,9 @@ pub async fn llm_chat(
         .and_then(|h| h.to_str().ok())
         .map(|s| s.to_string())
         .unwrap_or_else(|| {
-            // No traceparent - this is a root span, generate a new trace ID
             use uuid::Uuid;
             let trace_id = Uuid::new_v4().to_string().replace("-", "");
-            let span_id = Uuid::new_v4().to_string().replace("-", "")[..16].to_string();
-            // Format: version-trace_id-parent_span_id-trace_flags
-            format!("00-{}-{}-01", trace_id, span_id)
+            format!("00-{}-0000000000000000-01", trace_id)
         });
 
     let mut request_headers = request_headers;
@@ -273,7 +270,6 @@ async fn build_llm_span(
 
     let mut span_builder = SpanBuilder::new(&operation_name)
         .with_trace_id(&trace_id)
-        .with_parent_span_id(&parent_span_id)
         .with_kind(SpanKind::Client)
         .with_start_time(start_time)
         .with_attribute(http::METHOD, "POST")
@@ -283,6 +279,11 @@ async fn build_llm_span(
         .with_attribute(llm::MODEL_NAME, resolved_model.to_string())
         .with_attribute(llm::IS_STREAMING, is_streaming.to_string());
 
+    // Only set parent span ID if it exists (not a root span)
+    if let Some(parent) = parent_span_id {
+        span_builder = span_builder.with_parent_span_id(&parent);
+    }
+
     // Add optional attributes
     if let Some(temp) = temperature {
         span_builder = span_builder.with_attribute(llm::TEMPERATURE, temp.to_string());

crates/brightstaff/src/handlers/router_chat.rs

@@ -219,7 +219,6 @@ async fn record_routing_span(
     // Build the routing span directly using constants
     let mut span_builder = SpanBuilder::new(&routing_operation_name)
         .with_trace_id(&trace_id)
-        .with_parent_span_id(&parent_span_id)
         .with_kind(SpanKind::Client)
         .with_start_time(start_system_time)
         .with_end_time(std::time::SystemTime::now())
@@ -227,6 +226,11 @@ async fn record_routing_span(
         .with_attribute(http::TARGET, routing_api_path.to_string())
         .with_attribute(routing::ROUTE_DETERMINATION_MS, start_time.elapsed().as_millis().to_string());
 
+    // Only set parent span ID if it exists (not a root span)
+    if let Some(parent) = parent_span_id {
+        span_builder = span_builder.with_parent_span_id(&parent);
+    }
+
     // Add all custom attributes
     for (key, value) in attrs {
         span_builder = span_builder.with_attribute(key, value);

crates/common/src/traces/collector.rs

@@ -9,15 +9,26 @@ use tracing::{debug, error, warn};
 /// Parse W3C traceparent header into trace_id and parent_span_id
 /// Format: "00-{trace_id}-{parent_span_id}-01"
 ///
-/// Returns (trace_id, parent_span_id) as strings
-pub fn parse_traceparent(traceparent: &str) -> (String, String) {
+/// Returns (trace_id, Option<parent_span_id>)
+/// - parent_span_id is None if it's all zeros (0000000000000000), indicating a root span
+pub fn parse_traceparent(traceparent: &str) -> (String, Option<String>) {
     let parts: Vec<&str> = traceparent.split('-').collect();
     if parts.len() == 4 {
-        (parts[1].to_string(), parts[2].to_string())
+        let trace_id = parts[1].to_string();
+        let parent_span_id = parts[2].to_string();
+
+        // If parent_span_id is all zeros, this is a root span with no parent
+        let parent = if parent_span_id == "0000000000000000" {
+            None
+        } else {
+            Some(parent_span_id)
+        };
+
+        (trace_id, parent)
     } else {
         warn!("Invalid traceparent format: {}", traceparent);
-        // Generate empty IDs if parsing fails
-        (String::new(), String::new())
+        // Return empty trace ID and None for parent if parsing fails
+        (String::new(), None)
     }
 }