feat(observability): derive OTLP IDs from Relay UUIDs

crates/core/src/observability/mod.rs

@@ -72,6 +72,18 @@ pub(crate) fn default_mark_exclude_names() -> Vec<String> {
     vec!["llm.chunk".to_string()]
 }
 
+#[cfg(any(feature = "otel", feature = "openinference"))]
+pub(crate) fn relay_trace_id(uuid: uuid::Uuid) -> opentelemetry::trace::TraceId {
+    opentelemetry::trace::TraceId::from_bytes(*uuid.as_bytes())
+}
+
+#[cfg(any(feature = "otel", feature = "openinference"))]
+pub(crate) fn relay_span_id(uuid: uuid::Uuid) -> opentelemetry::trace::SpanId {
+    let mut bytes = [0; 8];
+    bytes.copy_from_slice(&uuid.as_bytes()[8..]);
+    opentelemetry::trace::SpanId::from_bytes(bytes)
+}
+
 #[cfg(any(feature = "otel", feature = "openinference"))]
 pub(crate) fn push_common_optimization_attributes(
     attributes: &mut Vec<opentelemetry::KeyValue>,
@@ -561,3 +573,17 @@ where
 #[cfg(all(test, any(feature = "otel", feature = "openinference")))]
 #[path = "../../tests/unit/observability/attribute_projection_tests.rs"]
 mod attribute_projection_tests;
+
+#[cfg(all(test, any(feature = "otel", feature = "openinference")))]
+mod tests {
+    use super::{relay_span_id, relay_trace_id};
+    use uuid::Uuid;
+
+    #[test]
+    fn relay_id_conversions_preserve_zero_bytes() {
+        let uuid = Uuid::nil();
+
+        assert_eq!(relay_trace_id(uuid).to_bytes(), [0; 16]);
+        assert_eq!(relay_span_id(uuid).to_bytes(), [0; 8]);
+    }
+}

crates/core/src/observability/openinference.rs

@@ -25,7 +25,8 @@ use super::{
     attribute_mapping_inputs, default_mark_exclude_names, effective_mark_projection,
     estimate_cost_for_response_or_model, estimate_cost_for_response_or_requested_model, manual,
     merge_usage, model_name_for_llm_event, push_serialized_top_level_attributes,
-    push_session_identity_attributes, push_top_level_json_attributes, validate_attribute_mappings,
+    push_session_identity_attributes, push_top_level_json_attributes, relay_span_id,
+    relay_trace_id, validate_attribute_mappings,
 };
 use crate::api::event::{Event, EventNormalizationExt, ScopeCategory};
 use crate::api::runtime::EventSubscriberFn;
@@ -634,6 +635,8 @@ impl OpenInferenceEventProcessor {
             .span_builder(span_name(event))
             .with_kind(span_kind(event))
             .with_start_time(to_system_time(*event.timestamp()))
+            .with_trace_id(relay_trace_id(event.uuid()))
+            .with_span_id(relay_span_id(event.uuid()))
             .start_with_context(&self.tracer, &parent_context);
         let mut attributes = start_attributes(event);
         if is_trace_root {
@@ -703,6 +706,8 @@ impl OpenInferenceEventProcessor {
             .span_builder(format!("mark:{mark_name}"))
             .with_kind(SpanKind::Internal)
             .with_start_time(timestamp)
+            .with_trace_id(relay_trace_id(event.uuid()))
+            .with_span_id(relay_span_id(event.uuid()))
             .start_with_context(&self.tracer, &self.parent_context(event));
         attributes.push(KeyValue::new(
             oi::OPENINFERENCE_SPAN_KIND,
@@ -737,6 +742,8 @@ impl OpenInferenceEventProcessor {
             .span_builder(format!("mark:{}", event.name()))
             .with_kind(SpanKind::Internal)
             .with_start_time(timestamp)
+            .with_trace_id(relay_trace_id(event.uuid()))
+            .with_span_id(relay_span_id(event.uuid()))
             .start_with_context(&self.tracer, &self.parent_context(event));
         span.set_attributes(attributes);
         span.end_with_timestamp(timestamp);

crates/core/src/observability/otel.rs

@@ -25,7 +25,8 @@ use super::{
     attribute_mapping_inputs, default_mark_exclude_names, effective_mark_projection,
     estimate_cost_for_response_or_model, estimate_cost_for_response_or_requested_model, manual,
     model_name_for_llm_event, push_serialized_top_level_attributes,
-    push_session_identity_attributes, push_top_level_json_attributes, validate_attribute_mappings,
+    push_session_identity_attributes, push_top_level_json_attributes, relay_span_id,
+    relay_trace_id, validate_attribute_mappings,
 };
 use crate::api::event::{Event, EventNormalizationExt, ScopeCategory};
 use crate::api::runtime::EventSubscriberFn;
@@ -627,6 +628,8 @@ impl OtelEventProcessor {
             .span_builder(span_name(event))
             .with_kind(span_kind(event))
             .with_start_time(to_system_time(*event.timestamp()))
+            .with_trace_id(relay_trace_id(event.uuid()))
+            .with_span_id(relay_span_id(event.uuid()))
             .start_with_context(&self.tracer, &parent_context);
         let mut attributes = start_attributes(event);
         if is_trace_root {
@@ -697,6 +700,8 @@ impl OtelEventProcessor {
             .span_builder(format!("mark:{mark_name}"))
             .with_kind(SpanKind::Internal)
             .with_start_time(timestamp)
+            .with_trace_id(relay_trace_id(event.uuid()))
+            .with_span_id(relay_span_id(event.uuid()))
             .start_with_context(&self.tracer, &self.parent_context(event));
         attributes.push(KeyValue::new("nemo_relay.mark.orphan", true));
         apply_attribute_mappings(&mut attributes, &self.attribute_mappings);
@@ -723,6 +728,8 @@ impl OtelEventProcessor {
             .span_builder(format!("mark:{}", event.name()))
             .with_kind(SpanKind::Internal)
             .with_start_time(timestamp)
+            .with_trace_id(relay_trace_id(event.uuid()))
+            .with_span_id(relay_span_id(event.uuid()))
             .start_with_context(&self.tracer, &self.parent_context(event));
         span.set_attributes(attributes);
         span.end_with_timestamp(timestamp);

crates/core/tests/unit/observability/exporter_parity_tests.rs

@@ -819,7 +819,7 @@ fn test_manual_fallback_payload_parity() {
 }
 
 #[test]
-fn session_instance_correlates_distinct_otel_and_openinference_traces() {
+fn session_instance_correlates_otel_and_openinference_traces() {
     let scope_stack = create_scope_stack();
     let expected_root_uuid = scope_stack.read().unwrap().root_uuid().to_string();
     let uuid = Uuid::now_v7();
@@ -874,7 +874,7 @@ fn session_instance_correlates_distinct_otel_and_openinference_traces() {
         openinference_attributes["nemo_relay.session.instance_id"],
         expected_root_uuid
     );
-    assert_ne!(
+    assert_eq!(
         otel.span_context.trace_id(),
         openinference.span_context.trace_id()
     );

crates/core/tests/unit/observability/openinference_tests.rs

@@ -2361,13 +2361,17 @@ fn tool_semantic_names_exist_without_input_payload() {
 }
 
 #[test]
-fn preserves_parent_child_relationships() {
+fn derives_span_ids_from_relay_uuids() {
     let (provider, exporter) = make_provider();
-    let mut processor =
-        OpenInferenceEventProcessor::new(provider.clone(), "test-scope".to_string());
+    let mut processor = OpenInferenceEventProcessor::new_with_mark_projection(
+        provider.clone(),
+        "test-scope".to_string(),
+        MarkProjection::Tool,
+    );
 
-    let root_uuid = Uuid::now_v7();
-    let child_uuid = Uuid::now_v7();
+    let root_uuid = Uuid::from_u128(0x018f_0f0f_0f0f_7000_8123_4567_89ab_cdef);
+    let child_uuid = Uuid::from_u128(0x018f_0f0f_0f10_7000_8fed_cba9_8765_4321);
+    let orphan_uuid = Uuid::from_u128(0x018f_0f0f_0f11_7000_8011_2233_4455_6677);
 
     processor.process(&make_start_event(
         root_uuid,
@@ -2397,11 +2401,19 @@ fn preserves_parent_child_relationships() {
         ScopeType::Agent,
         None,
     ));
+    processor.process(&Event::Mark(MarkEvent::new(
+        BaseEvent::builder()
+            .uuid(orphan_uuid)
+            .name("checkpoint")
+            .build(),
+        None,
+        None,
+    )));
 
     processor.force_flush().unwrap();
 
     let spans = exporter.get_finished_spans().unwrap();
-    assert_eq!(spans.len(), 2);
+    assert_eq!(spans.len(), 3);
     let parent = spans
         .iter()
         .find(|span| span.name.as_ref() == "agent")
@@ -2410,13 +2422,37 @@ fn preserves_parent_child_relationships() {
         .iter()
         .find(|span| span.name.as_ref() == "model-call")
         .unwrap();
+    let orphan = spans
+        .iter()
+        .find(|span| span.name.as_ref() == "mark:checkpoint")
+        .unwrap();
 
+    assert_eq!(
+        parent.span_context.trace_id().to_bytes(),
+        *root_uuid.as_bytes()
+    );
+    assert_eq!(
+        parent.span_context.span_id().to_bytes(),
+        root_uuid.as_bytes()[8..]
+    );
     assert_eq!(
         child.span_context.trace_id(),
         parent.span_context.trace_id()
     );
+    assert_eq!(
+        child.span_context.span_id().to_bytes(),
+        child_uuid.as_bytes()[8..]
+    );
     assert_eq!(child.parent_span_id, parent.span_context.span_id());
     assert!(!child.parent_span_is_remote);
+    assert_eq!(
+        orphan.span_context.trace_id().to_bytes(),
+        *orphan_uuid.as_bytes()
+    );
+    assert_eq!(
+        orphan.span_context.span_id().to_bytes(),
+        orphan_uuid.as_bytes()[8..]
+    );
 }
 
 #[test]

crates/core/tests/unit/observability/otel_tests.rs

@@ -1049,12 +1049,17 @@ fn records_span_start_mark_and_end() {
 }
 
 #[test]
-fn preserves_parent_child_relationships() {
+fn derives_span_ids_from_relay_uuids() {
     let (provider, exporter) = make_provider();
-    let mut processor = OtelEventProcessor::new(provider.clone(), "test-scope".to_string());
+    let mut processor = OtelEventProcessor::new_with_mark_projection(
+        provider.clone(),
+        "test-scope".to_string(),
+        MarkProjection::Tool,
+    );
 
-    let root_uuid = Uuid::now_v7();
-    let child_uuid = Uuid::now_v7();
+    let root_uuid = Uuid::from_u128(0x018f_0f0f_0f0f_7000_8123_4567_89ab_cdef);
+    let child_uuid = Uuid::from_u128(0x018f_0f0f_0f10_7000_8fed_cba9_8765_4321);
+    let orphan_uuid = Uuid::from_u128(0x018f_0f0f_0f11_7000_8011_2233_4455_6677);
 
     processor.process(&make_start_event(
         root_uuid,
@@ -1084,11 +1089,19 @@ fn preserves_parent_child_relationships() {
         ScopeType::Agent,
         None,
     ));
+    processor.process(&Event::Mark(MarkEvent::new(
+        BaseEvent::builder()
+            .uuid(orphan_uuid)
+            .name("checkpoint")
+            .build(),
+        None,
+        None,
+    )));
 
     processor.force_flush().unwrap();
 
     let spans = exporter.get_finished_spans().unwrap();
-    assert_eq!(spans.len(), 2);
+    assert_eq!(spans.len(), 3);
     let parent = spans
         .iter()
         .find(|span| span.name.as_ref() == "agent")
@@ -1097,13 +1110,37 @@ fn preserves_parent_child_relationships() {
         .iter()
         .find(|span| span.name.as_ref() == "model-call")
         .unwrap();
+    let orphan = spans
+        .iter()
+        .find(|span| span.name.as_ref() == "mark:checkpoint")
+        .unwrap();
 
+    assert_eq!(
+        parent.span_context.trace_id().to_bytes(),
+        *root_uuid.as_bytes()
+    );
+    assert_eq!(
+        parent.span_context.span_id().to_bytes(),
+        root_uuid.as_bytes()[8..]
+    );
     assert_eq!(
         child.span_context.trace_id(),
         parent.span_context.trace_id()
     );
+    assert_eq!(
+        child.span_context.span_id().to_bytes(),
+        child_uuid.as_bytes()[8..]
+    );
     assert_eq!(child.parent_span_id, parent.span_context.span_id());
     assert!(!child.parent_span_is_remote);
+    assert_eq!(
+        orphan.span_context.trace_id().to_bytes(),
+        *orphan_uuid.as_bytes()
+    );
+    assert_eq!(
+        orphan.span_context.span_id().to_bytes(),
+        orphan_uuid.as_bytes()[8..]
+    );
 }
 
 #[test]