diff --git a/pkgs/telemetry/src/LaunchDarkly.ServerSdk.Telemetry.csproj b/pkgs/telemetry/src/LaunchDarkly.ServerSdk.Telemetry.csproj
index db6c783f..95ef789a 100644
--- a/pkgs/telemetry/src/LaunchDarkly.ServerSdk.Telemetry.csproj
+++ b/pkgs/telemetry/src/LaunchDarkly.ServerSdk.Telemetry.csproj
@@ -37,7 +37,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="LaunchDarkly.ServerSdk" Version="8.*" />
+    <PackageReference Include="LaunchDarkly.ServerSdk" Version="[8.7, 9.0)" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'net462'">
diff --git a/pkgs/telemetry/src/TracingHook.cs b/pkgs/telemetry/src/TracingHook.cs
index f33acd4c..81323cf0 100644
--- a/pkgs/telemetry/src/TracingHook.cs
+++ b/pkgs/telemetry/src/TracingHook.cs
@@ -16,11 +16,13 @@ public class TracingHookBuilder
     {
         private bool _createActivities;
         private bool _includeVariant;
+        private string _environmentId;
 
         internal TracingHookBuilder()
         {
             _createActivities = false;
             _includeVariant = false;
+            _environmentId = null;
         }
 
         /// <summary>
@@ -51,6 +53,22 @@ public TracingHookBuilder IncludeVariant(bool includeVariant = true)
             return this;
         }
 
+        /// <summary>
+        /// The environment ID associated with the SDK configuration. In typical usage the environment ID should not be
+        /// specified. The environment ID only needs to be manually specified if it cannot be retrieved from the SDK.
+        /// <para>
+        /// This is not the same as the SDK key. The environment ID is equivalent to the client-side ID in the
+        /// LaunchDarkly UI and documentation.
+        /// </para>
+        /// </summary>
+        /// <param name="environmentId">The environment the SDK is configured to connect to.</param>
+        /// <returns>this builder</returns>
+        public TracingHookBuilder EnvironmentId(string environmentId)
+        {
+            _environmentId = environmentId;
+            return this;
+        }
+
         /// <summary>
         /// Builds the <see cref="TracingHook"/> with the configured options.
         ///
@@ -59,7 +77,7 @@ public TracingHookBuilder IncludeVariant(bool includeVariant = true)
         /// <returns>the new hook</returns>
         public TracingHook Build()
         {
-            return new TracingHook(new TracingHook.Options(_createActivities, _includeVariant));
+            return new TracingHook(new TracingHook.Options(_createActivities, _includeVariant, _environmentId));
         }
     }
 
@@ -92,6 +110,7 @@ private static class SemanticAttributes
             public const string FeatureFlagProviderName = "feature_flag.provider_name";
             public const string FeatureFlagVariant = "feature_flag.variant";
             public const string FeatureFlagContextKeyAttributeName = "feature_flag.context.key";
+            public const string FeatureFlagSetId = "feature_flag.set.id";
         }
 
         internal struct Options
@@ -99,10 +118,13 @@ internal struct Options
             public bool CreateActivities { get; }
             public bool IncludeVariant { get; }
 
-            public Options(bool createActivities, bool includeVariant)
+            public string EnvironmentId { get; }
+
+            public Options(bool createActivities, bool includeVariant, string environmentId = null)
             {
                 CreateActivities = createActivities;
                 IncludeVariant = includeVariant;
+                EnvironmentId = environmentId;
             }
         }
 
@@ -185,6 +207,15 @@ public override SeriesData AfterEvaluation(EvaluationSeriesContext context, Seri
                 {SemanticAttributes.FeatureFlagContextKeyAttributeName, context.Context.FullyQualifiedKey},
             };
 
+            if (_options.EnvironmentId != null)
+            {
+                attributes[SemanticAttributes.FeatureFlagSetId] = _options.EnvironmentId;
+            }
+            else if (context.EnvironmentId != null)
+            {
+                attributes[SemanticAttributes.FeatureFlagSetId] = context.EnvironmentId;
+            }
+
             if (_options.IncludeVariant)
             {
                 attributes.Add(SemanticAttributes.FeatureFlagVariant, detail.Value.ToJsonString());
diff --git a/pkgs/telemetry/test/TracingHookTests.cs b/pkgs/telemetry/test/TracingHookTests.cs
index 912429a0..70c2402c 100644
--- a/pkgs/telemetry/test/TracingHookTests.cs
+++ b/pkgs/telemetry/test/TracingHookTests.cs
@@ -19,6 +19,13 @@ public void CanConstructTracingHook()
             Assert.Equal("LaunchDarkly Tracing Hook", hook.Metadata.Name);
         }
 
+        [Fact]
+        public void CanConstructTracingHookWithEnvironmentId()
+        {
+            var hook = TracingHook.Builder().EnvironmentId("env-123").Build();
+            Assert.NotNull(hook);
+        }
+
         [Fact]
         public void CanRetrieveActivitySourceName()
         {
@@ -64,12 +71,14 @@ public void TracingHookCreatesRootSpans(bool createSpans)
             var featureKey = "feature-key";
             var context = Context.New("foo");
 
-            var evalContext1 = new EvaluationSeriesContext(featureKey, context, LdValue.Of(true), "LdClient.BoolVariation");
+            var evalContext1 =
+                new EvaluationSeriesContext(featureKey, context, LdValue.Of(true), "LdClient.BoolVariation");
             var data1 = hookUnderTest.BeforeEvaluation(evalContext1, new SeriesDataBuilder().Build());
             hookUnderTest.AfterEvaluation(evalContext1, data1,
                 new EvaluationDetail<LdValue>(LdValue.Of(true), 0, EvaluationReason.FallthroughReason));
 
-            var evalContext2 = new EvaluationSeriesContext(featureKey, context, LdValue.Of("default"), "LdClient.StringVariation");
+            var evalContext2 =
+                new EvaluationSeriesContext(featureKey, context, LdValue.Of("default"), "LdClient.StringVariation");
             var data2 = hookUnderTest.BeforeEvaluation(evalContext2, new SeriesDataBuilder().Build());
             hookUnderTest.AfterEvaluation(evalContext2, data2,
                 new EvaluationDetail<LdValue>(LdValue.Of("default"), 0, EvaluationReason.FallthroughReason));
@@ -117,12 +126,14 @@ public void TracingHookCreatesChildSpans(bool createSpans)
 
             var rootActivity = testSource.StartActivity("root-activity");
 
-            var evalContext1 = new EvaluationSeriesContext(featureKey, context, LdValue.Of(true), "LdClient.BoolVariation");
+            var evalContext1 =
+                new EvaluationSeriesContext(featureKey, context, LdValue.Of(true), "LdClient.BoolVariation");
             var data1 = hookUnderTest.BeforeEvaluation(evalContext1, new SeriesDataBuilder().Build());
             hookUnderTest.AfterEvaluation(evalContext1, data1,
                 new EvaluationDetail<LdValue>(LdValue.Of(true), 0, EvaluationReason.FallthroughReason));
 
-            var evalContext2 = new EvaluationSeriesContext(featureKey, context, LdValue.Of("default"), "LdClient.StringVariation");
+            var evalContext2 =
+                new EvaluationSeriesContext(featureKey, context, LdValue.Of("default"), "LdClient.StringVariation");
             var data2 = hookUnderTest.BeforeEvaluation(evalContext2, new SeriesDataBuilder().Build());
             hookUnderTest.AfterEvaluation(evalContext2, data2,
                 new EvaluationDetail<LdValue>(LdValue.Of("default"), 0, EvaluationReason.FallthroughReason));
@@ -173,12 +184,14 @@ public void TracingHookIncludesVariant(bool includeVariant)
 
             var rootActivity = testSource.StartActivity("root-activity");
 
-            var evalContext1 = new EvaluationSeriesContext(featureKey, context, LdValue.Of(true), "LdClient.BoolVariation");
+            var evalContext1 =
+                new EvaluationSeriesContext(featureKey, context, LdValue.Of(true), "LdClient.BoolVariation");
             var data1 = hookUnderTest.BeforeEvaluation(evalContext1, new SeriesDataBuilder().Build());
             hookUnderTest.AfterEvaluation(evalContext1, data1,
                 new EvaluationDetail<LdValue>(LdValue.Of(true), 0, EvaluationReason.FallthroughReason));
 
-            var evalContext2 = new EvaluationSeriesContext(featureKey, context, LdValue.Of("default"), "LdClient.StringVariation");
+            var evalContext2 =
+                new EvaluationSeriesContext(featureKey, context, LdValue.Of("default"), "LdClient.StringVariation");
             var data2 = hookUnderTest.BeforeEvaluation(evalContext2, new SeriesDataBuilder().Build());
             hookUnderTest.AfterEvaluation(evalContext2, data2,
                 new EvaluationDetail<LdValue>(LdValue.Of("default"), 0, EvaluationReason.FallthroughReason));
@@ -207,5 +220,123 @@ public void TracingHookIncludesVariant(bool includeVariant)
                 Assert.All(items, i => i.Events.All(e => e.Tags.All(kvp => kvp.Key != "feature_flag.variant")));
             }
         }
+
+
+        [Fact]
+        public void TracingHookIncludesEnvironmentIdWhenSpecified()
+        {
+            ICollection<Activity> exportedItems = new Collection<Activity>();
+
+            _ = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+                .AddSource("test-source")
+                .SetResourceBuilder(
+                    ResourceBuilder.CreateDefault()
+                        .AddService(serviceName: "test-source", serviceVersion: "1.0.0"))
+                .AddInMemoryExporter(exportedItems)
+                .Build();
+
+            var testSource = new ActivitySource("test-source", "1.0.0");
+
+            var hookUnderTest = TracingHook.Builder().EnvironmentId("env-123").Build();
+            var featureKey = "feature-key";
+            var context = Context.New("foo");
+
+            var rootActivity = testSource.StartActivity("root-activity");
+
+            var evalContext1 =
+                new EvaluationSeriesContext(featureKey, context, LdValue.Of(true), "LdClient.BoolVariation");
+            var data1 = hookUnderTest.BeforeEvaluation(evalContext1, new SeriesDataBuilder().Build());
+            hookUnderTest.AfterEvaluation(evalContext1, data1,
+                new EvaluationDetail<LdValue>(LdValue.Of(true), 0, EvaluationReason.FallthroughReason));
+
+            rootActivity.Stop();
+
+            var items = exportedItems.ToList();
+
+            Assert.Single(items);
+            Assert.Equal("root-activity", items[0].OperationName);
+
+            var events = items[0].Events;
+            Assert.Single(events.Where(e =>
+                e.Tags.Contains(new KeyValuePair<string, object>("feature_flag.set.id", "env-123"))));
+        }
+
+        [Fact]
+        public void TracingHookUsesEnvironmentIdFromContext()
+        {
+            ICollection<Activity> exportedItems = new Collection<Activity>();
+
+            _ = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+                .AddSource("test-source")
+                .SetResourceBuilder(
+                    ResourceBuilder.CreateDefault()
+                        .AddService(serviceName: "test-source", serviceVersion: "1.0.0"))
+                .AddInMemoryExporter(exportedItems)
+                .Build();
+
+            var testSource = new ActivitySource("test-source", "1.0.0");
+
+            var hookUnderTest = TracingHook.Builder().Build();
+            var featureKey = "feature-key";
+            var context = Context.New("foo");
+
+            var rootActivity = testSource.StartActivity("root-activity");
+
+            var evalContext1 = new EvaluationSeriesContext(featureKey, context, LdValue.Of(true),
+                "LdClient.BoolVariation", "env-456");
+            var data1 = hookUnderTest.BeforeEvaluation(evalContext1, new SeriesDataBuilder().Build());
+            hookUnderTest.AfterEvaluation(evalContext1, data1,
+                new EvaluationDetail<LdValue>(LdValue.Of(true), 0, EvaluationReason.FallthroughReason));
+
+            rootActivity.Stop();
+
+            var items = exportedItems.ToList();
+
+            Assert.Single(items);
+            Assert.Equal("root-activity", items[0].OperationName);
+
+            var events = items[0].Events;
+            Assert.Single(events.Where(e =>
+                e.Tags.Contains(new KeyValuePair<string, object>("feature_flag.set.id", "env-456"))));
+        }
+
+        [Fact]
+        public void TracingHookPrioritizesEnvironmentIdFromOptions()
+        {
+            ICollection<Activity> exportedItems = new Collection<Activity>();
+
+            _ = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+                .AddSource("test-source")
+                .SetResourceBuilder(
+                    ResourceBuilder.CreateDefault()
+                        .AddService(serviceName: "test-source", serviceVersion: "1.0.0"))
+                .AddInMemoryExporter(exportedItems)
+                .Build();
+
+            var testSource = new ActivitySource("test-source", "1.0.0");
+
+            var hookUnderTest = TracingHook.Builder().EnvironmentId("env-123").Build();
+            var featureKey = "feature-key";
+            var context = Context.New("foo");
+
+            var rootActivity = testSource.StartActivity("root-activity");
+
+            var evalContext1 = new EvaluationSeriesContext(featureKey, context, LdValue.Of(true),
+                "LdClient.BoolVariation", "env-456");
+            var data1 = hookUnderTest.BeforeEvaluation(evalContext1, new SeriesDataBuilder().Build());
+            hookUnderTest.AfterEvaluation(evalContext1, data1,
+                new EvaluationDetail<LdValue>(LdValue.Of(true), 0, EvaluationReason.FallthroughReason));
+
+            rootActivity.Stop();
+
+            var items = exportedItems.ToList();
+
+            Assert.Single(items);
+            Assert.Equal("root-activity", items[0].OperationName);
+
+            var events = items[0].Events;
+            Assert.Single(events.Where(e =>
+                e.Tags.Contains(new KeyValuePair<string, object>("feature_flag.set.id", "env-123"))));
+        }
     }
 }