From 3dd53f97bd284b6dd97b2d6729b005ea644f0f97 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Mon, 15 Dec 2025 23:47:18 +0000
Subject: [PATCH] feat: Include gen_ai.conversation.id in OTEL spans

This change adds the `gen_ai.conversation.id` attribute to the OpenTelemetry spans for LLM calls, tool calls, and merged tool calls. This allows for better linking of messages within a conversation in AI evaluation platforms.

The `gen_ai.conversation.id` attribute is populated with the existing session ID.

This addresses the issue where each message in a conversation was not linked together when using the OTEL integration.
---
 internal/llminternal/base_flow.go | 4 ++--
 internal/telemetry/telemetry.go   | 8 ++++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/internal/llminternal/base_flow.go b/internal/llminternal/base_flow.go
index 15937e23a..6f92d305f 100644
--- a/internal/llminternal/base_flow.go
+++ b/internal/llminternal/base_flow.go
@@ -406,7 +406,7 @@ func (f *Flow) handleFunctionCalls(ctx agent.InvocationContext, toolsDict map[st
 		ev.Author = ctx.Agent().Name()
 		ev.Branch = ctx.Branch()
 		ev.Actions = *toolCtx.Actions()
-		telemetry.TraceToolCall(spans, curTool, fnCall.Args, ev)
+		telemetry.TraceToolCall(spans, ctx, curTool, fnCall.Args, ev)
 		fnResponseEvents = append(fnResponseEvents, ev)
 	}
 	mergedEvent, err := mergeParallelFunctionResponseEvents(fnResponseEvents)
@@ -415,7 +415,7 @@ func (f *Flow) handleFunctionCalls(ctx agent.InvocationContext, toolsDict map[st
 	}
 	// this is needed for debug traces of parallel calls
 	spans := telemetry.StartTrace(ctx, "execute_tool (merged)")
-	telemetry.TraceMergedToolCalls(spans, mergedEvent)
+	telemetry.TraceMergedToolCalls(spans, ctx, mergedEvent)
 	return mergedEvent, nil
 }
 
diff --git a/internal/telemetry/telemetry.go b/internal/telemetry/telemetry.go
index cc3f65c03..142c5d72b 100644
--- a/internal/telemetry/telemetry.go
+++ b/internal/telemetry/telemetry.go
@@ -58,6 +58,7 @@ const (
 	genAiToolCallID       = "gen_ai.tool.call.id"
 	genAiSystemName       = "gen_ai.system"
 	genAiRequestModelName = "gen_ai.request.model"
+	genAiConversationID   = "gen_ai.conversation.id"
 
 	gcpVertexAgentLLMRequestName   = "gcp.vertex.agent.llm_request"
 	gcpVertexAgentToolCallArgsName = "gcp.vertex.agent.tool_call_args"
@@ -118,12 +119,13 @@ func StartTrace(ctx context.Context, traceName string) []trace.Span {
 }
 
 // TraceMergedToolCalls traces the tool execution events.
-func TraceMergedToolCalls(spans []trace.Span, fnResponseEvent *session.Event) {
+func TraceMergedToolCalls(spans []trace.Span, agentCtx agent.InvocationContext, fnResponseEvent *session.Event) {
 	if fnResponseEvent == nil {
 		return
 	}
 	for _, span := range spans {
 		attributes := []attribute.KeyValue{
+			attribute.String(genAiConversationID, agentCtx.Session().ID()),
 			attribute.String(genAiOperationName, executeToolName),
 			attribute.String(genAiToolName, mergeToolName),
 			attribute.String(genAiToolDescription, mergeToolName),
@@ -141,12 +143,13 @@ func TraceMergedToolCalls(spans []trace.Span, fnResponseEvent *session.Event) {
 }
 
 // TraceToolCall traces the tool execution events.
-func TraceToolCall(spans []trace.Span, tool tool.Tool, fnArgs map[string]any, fnResponseEvent *session.Event) {
+func TraceToolCall(spans []trace.Span, agentCtx agent.InvocationContext, tool tool.Tool, fnArgs map[string]any, fnResponseEvent *session.Event) {
 	if fnResponseEvent == nil {
 		return
 	}
 	for _, span := range spans {
 		attributes := []attribute.KeyValue{
+			attribute.String(genAiConversationID, agentCtx.Session().ID()),
 			attribute.String(genAiOperationName, executeToolName),
 			attribute.String(genAiToolName, tool.Name()),
 			attribute.String(genAiToolDescription, tool.Description()),
@@ -195,6 +198,7 @@ func TraceLLMCall(spans []trace.Span, agentCtx agent.InvocationContext, llmReque
 			attribute.String(genAiRequestModelName, llmRequest.Model),
 			attribute.String(gcpVertexAgentInvocationID, event.InvocationID),
 			attribute.String(gcpVertexAgentSessionID, agentCtx.Session().ID()),
+			attribute.String(genAiConversationID, agentCtx.Session().ID()),
 			attribute.String(gcpVertexAgentEventID, event.ID),
 			attribute.String(gcpVertexAgentLLMRequestName, safeSerialize(llmRequestToTrace(llmRequest))),
 			attribute.String(gcpVertexAgentLLMResponseName, safeSerialize(event.LLMResponse)),