diff --git a/Integration/Base/Base.csproj b/Integration/Base/Base.csproj
index 6a869479a..607f889ef 100644
--- a/Integration/Base/Base.csproj
+++ b/Integration/Base/Base.csproj
@@ -6,6 +6,7 @@
 
     <ItemGroup>
       <PackageReference Include="mongodb.driver" />
+      <PackageReference Include="System.Reactive" />
       <PackageReference Include="Testcontainers" />
     </ItemGroup>
 </Project>
diff --git a/Integration/Orleans.InProcess/Orleans.InProcess.csproj b/Integration/Orleans.InProcess/Orleans.InProcess.csproj
index c79dc5101..f092ddcd7 100644
--- a/Integration/Orleans.InProcess/Orleans.InProcess.csproj
+++ b/Integration/Orleans.InProcess/Orleans.InProcess.csproj
@@ -14,6 +14,7 @@
     <ItemGroup>
       <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" />
       <PackageReference Include="Cratis.Applications.MongoDB" />
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 
     <ItemGroup>
diff --git a/Samples/Orleans/Orleans.csproj b/Samples/Orleans/Orleans.csproj
index 9eaa3d53b..5ce67a416 100644
--- a/Samples/Orleans/Orleans.csproj
+++ b/Samples/Orleans/Orleans.csproj
@@ -21,5 +21,6 @@
         <PackageReference Include="Microsoft.Orleans.Server" />
         <PackageReference Include="Microsoft.Orleans.Serialization.SystemTextJson" />
         <PackageReference Include="OrleansDashboard" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Api/Api.csproj b/Source/Api/Api.csproj
index 84a18a100..9c1a3fc89 100644
--- a/Source/Api/Api.csproj
+++ b/Source/Api/Api.csproj
@@ -27,5 +27,6 @@
       <PackageReference Include="Cratis.Applications" />
       <PackageReference Include="Microsoft.Orleans.Core.Abstractions" />
       <PackageReference Include="Cratis.Applications.ProxyGenerator.Build" />
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Clients/AspNetCore.Specs/AspNetCore.Specs.csproj b/Source/Clients/AspNetCore.Specs/AspNetCore.Specs.csproj
index 189dc8f13..de94191f5 100644
--- a/Source/Clients/AspNetCore.Specs/AspNetCore.Specs.csproj
+++ b/Source/Clients/AspNetCore.Specs/AspNetCore.Specs.csproj
@@ -7,6 +7,10 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../../../Source/Clients/AspNetCore/AspNetCore.csproj"/>
+        <ProjectReference Include="../../../Source/Clients/AspNetCore/AspNetCore.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Clients/AspNetCore/AspNetCore.csproj b/Source/Clients/AspNetCore/AspNetCore.csproj
index b305139c2..5eea64538 100644
--- a/Source/Clients/AspNetCore/AspNetCore.csproj
+++ b/Source/Clients/AspNetCore/AspNetCore.csproj
@@ -9,6 +9,10 @@
     </ItemGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../DotNET/DotNET.csproj"/>
+        <ProjectReference Include="../DotNET/DotNET.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Clients/AssemblyFixer/AssemblyFixer.csproj b/Source/Clients/AssemblyFixer/AssemblyFixer.csproj
index 28724bd2b..59af6656a 100644
--- a/Source/Clients/AssemblyFixer/AssemblyFixer.csproj
+++ b/Source/Clients/AssemblyFixer/AssemblyFixer.csproj
@@ -8,5 +8,6 @@
     </PropertyGroup>
     <ItemGroup>
       <PackageReference Include="Mono.Cecil" />
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Clients/DotNET.Specs/DotNET.Specs.csproj b/Source/Clients/DotNET.Specs/DotNET.Specs.csproj
index 5610bbb19..117691c6e 100644
--- a/Source/Clients/DotNET.Specs/DotNET.Specs.csproj
+++ b/Source/Clients/DotNET.Specs/DotNET.Specs.csproj
@@ -7,12 +7,13 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../DotNET/DotNET.csproj"/>
-        <ProjectReference Include="../../Kernel/Contracts/Contracts.csproj"/>
-        <ProjectReference Include="../../Infrastructure/Infrastructure.csproj"/>
+        <ProjectReference Include="../DotNET/DotNET.csproj" />
+        <ProjectReference Include="../../Kernel/Contracts/Contracts.csproj" />
+        <ProjectReference Include="../../Infrastructure/Infrastructure.csproj" />
     </ItemGroup>
 
     <ItemGroup>
         <PackageReference Include="Cratis.Applications" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Clients/Orleans.InProcess/Orleans.InProcess.csproj b/Source/Clients/Orleans.InProcess/Orleans.InProcess.csproj
index 6dfab0b27..625f7d0eb 100644
--- a/Source/Clients/Orleans.InProcess/Orleans.InProcess.csproj
+++ b/Source/Clients/Orleans.InProcess/Orleans.InProcess.csproj
@@ -74,5 +74,6 @@
         <PackageReference Include="protobuf-net.Grpc" />
         <PackageReference Include="Cratis.Applications.Orleans" />
         <PackageReference Include="NJsonSchema" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Clients/Orleans.XUnit/Orleans.XUnit.csproj b/Source/Clients/Orleans.XUnit/Orleans.XUnit.csproj
index c47b26905..244356ae6 100644
--- a/Source/Clients/Orleans.XUnit/Orleans.XUnit.csproj
+++ b/Source/Clients/Orleans.XUnit/Orleans.XUnit.csproj
@@ -7,8 +7,8 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../XUnit/XUnit.csproj"/>
-        <ProjectReference Include="../Orleans/Orleans.csproj"/>
+        <ProjectReference Include="../XUnit/XUnit.csproj" />
+        <ProjectReference Include="../Orleans/Orleans.csproj" />
 
         <ProjectReference Include="../../Kernel/Concepts/Concepts.csproj">
             <PrivateAssets>all</PrivateAssets>
@@ -17,6 +17,7 @@
     </ItemGroup>
 
     <ItemGroup>
+        <PackageReference Include="System.Reactive" />
         <PackageReference Include="xunit">
             <PrivateAssets>all</PrivateAssets>
         </PackageReference>
diff --git a/Source/Clients/Orleans/Orleans.csproj b/Source/Clients/Orleans/Orleans.csproj
index 25c4d97e3..49fed2e22 100644
--- a/Source/Clients/Orleans/Orleans.csproj
+++ b/Source/Clients/Orleans/Orleans.csproj
@@ -18,5 +18,6 @@
             <PrivateAssets>all</PrivateAssets>
         </PackageReference> -->
         <PackageReference Include="Microsoft.Orleans.Sdk" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Clients/XUnit/XUnit.csproj b/Source/Clients/XUnit/XUnit.csproj
index 8237ae377..d09325977 100644
--- a/Source/Clients/XUnit/XUnit.csproj
+++ b/Source/Clients/XUnit/XUnit.csproj
@@ -6,11 +6,12 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../DotNET/DotNET.csproj"/>
-        <ProjectReference Include="../../Infrastructure/Infrastructure.csproj"/>
+        <ProjectReference Include="../DotNET/DotNET.csproj" />
+        <ProjectReference Include="../../Infrastructure/Infrastructure.csproj" />
     </ItemGroup>
 
     <ItemGroup>
+        <PackageReference Include="System.Reactive" />
         <PackageReference Include="xunit">
             <PrivateAssets>all</PrivateAssets>
         </PackageReference>
diff --git a/Source/Infrastructure.Specs/Infrastructure.Specs.csproj b/Source/Infrastructure.Specs/Infrastructure.Specs.csproj
index 7e4103db5..fcd92cde8 100644
--- a/Source/Infrastructure.Specs/Infrastructure.Specs.csproj
+++ b/Source/Infrastructure.Specs/Infrastructure.Specs.csproj
@@ -7,10 +7,11 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../Infrastructure/Infrastructure.csproj"/>
+        <ProjectReference Include="../Infrastructure/Infrastructure.csproj" />
     </ItemGroup>
 
     <ItemGroup>
-        <PackageReference Include="Cratis.Applications"/>
+        <PackageReference Include="Cratis.Applications" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Kernel/Compliance.Specs/Compliance.Specs.csproj b/Source/Kernel/Compliance.Specs/Compliance.Specs.csproj
index a07d8f7cd..3b8c02921 100644
--- a/Source/Kernel/Compliance.Specs/Compliance.Specs.csproj
+++ b/Source/Kernel/Compliance.Specs/Compliance.Specs.csproj
@@ -7,8 +7,12 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../Compliance/Compliance.csproj"/>
-        <ProjectReference Include="../Concepts/Concepts.csproj"/>
+        <ProjectReference Include="../Compliance/Compliance.csproj" />
+        <ProjectReference Include="../Concepts/Concepts.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 
 </Project>
diff --git a/Source/Kernel/Compliance/Compliance.csproj b/Source/Kernel/Compliance/Compliance.csproj
index fc6589c70..6bf71ba55 100644
--- a/Source/Kernel/Compliance/Compliance.csproj
+++ b/Source/Kernel/Compliance/Compliance.csproj
@@ -5,9 +5,13 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../Storage/Storage.csproj"/>
+        <ProjectReference Include="../Storage/Storage.csproj" />
         <ProjectReference Include="../Concepts/Concepts.csproj">
             <PrivateAssets>all</PrivateAssets>
         </ProjectReference>
     </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
+    </ItemGroup>
 </Project>
diff --git a/Source/Kernel/Concepts.Specs/Concepts.Specs.csproj b/Source/Kernel/Concepts.Specs/Concepts.Specs.csproj
index c3bc03ea5..68724d97d 100644
--- a/Source/Kernel/Concepts.Specs/Concepts.Specs.csproj
+++ b/Source/Kernel/Concepts.Specs/Concepts.Specs.csproj
@@ -7,7 +7,11 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../Concepts/Concepts.csproj"/>
+        <ProjectReference Include="../Concepts/Concepts.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 
 </Project>
diff --git a/Source/Kernel/Concepts/Concepts.csproj b/Source/Kernel/Concepts/Concepts.csproj
index cf8a6435a..3e58d836c 100644
--- a/Source/Kernel/Concepts/Concepts.csproj
+++ b/Source/Kernel/Concepts/Concepts.csproj
@@ -12,4 +12,8 @@
             <PrivateAssets>all</PrivateAssets>
         </ProjectReference>
     </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
+    </ItemGroup>
 </Project>
diff --git a/Source/Kernel/Contracts/Contracts.csproj b/Source/Kernel/Contracts/Contracts.csproj
index 2dcb1fee1..059213e37 100644
--- a/Source/Kernel/Contracts/Contracts.csproj
+++ b/Source/Kernel/Contracts/Contracts.csproj
@@ -13,5 +13,6 @@
             <PrivateAssets>all</PrivateAssets>
         </PackageReference>
         <PackageReference Include="protobuf-net.Grpc" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Kernel/Diagnostics/Diagnostics.csproj b/Source/Kernel/Diagnostics/Diagnostics.csproj
index 706edb33d..d5d211992 100644
--- a/Source/Kernel/Diagnostics/Diagnostics.csproj
+++ b/Source/Kernel/Diagnostics/Diagnostics.csproj
@@ -11,6 +11,7 @@
         <PackageReference Include="OpenTelemetry.Instrumentation.Http" />
         <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" />
         <PackageReference Include="OpenTelemetry.Instrumentation.GrpcNetClient" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
     <ItemGroup>
         <ProjectReference Include="../Concepts/Concepts.csproj" />
diff --git a/Source/Kernel/Events/Events.csproj b/Source/Kernel/Events/Events.csproj
index e9f82a624..2280f6c44 100644
--- a/Source/Kernel/Events/Events.csproj
+++ b/Source/Kernel/Events/Events.csproj
@@ -10,4 +10,8 @@
         </ProjectReference>
     </ItemGroup>
 
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
+    </ItemGroup>
+
 </Project>
diff --git a/Source/Kernel/Grains.Interfaces.Specs/Grains.Interfaces.Specs.csproj b/Source/Kernel/Grains.Interfaces.Specs/Grains.Interfaces.Specs.csproj
index d4345869c..d46a5b709 100644
--- a/Source/Kernel/Grains.Interfaces.Specs/Grains.Interfaces.Specs.csproj
+++ b/Source/Kernel/Grains.Interfaces.Specs/Grains.Interfaces.Specs.csproj
@@ -11,4 +11,8 @@
         <ProjectReference Include="../Concepts/Concepts.csproj" />
     </ItemGroup>
 
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
+    </ItemGroup>
+
 </Project>
diff --git a/Source/Kernel/Grains.Interfaces/Grains.Interfaces.csproj b/Source/Kernel/Grains.Interfaces/Grains.Interfaces.csproj
index 8845c5577..fcbae7f35 100644
--- a/Source/Kernel/Grains.Interfaces/Grains.Interfaces.csproj
+++ b/Source/Kernel/Grains.Interfaces/Grains.Interfaces.csproj
@@ -17,5 +17,6 @@
     <ItemGroup>
         <PackageReference Include="Microsoft.Orleans.Sdk" />
         <PackageReference Include="Cratis.Applications.Orleans" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Kernel/Grains.Specs/Grains.Specs.csproj b/Source/Kernel/Grains.Specs/Grains.Specs.csproj
index 1947d77a5..738ab7a78 100644
--- a/Source/Kernel/Grains.Specs/Grains.Specs.csproj
+++ b/Source/Kernel/Grains.Specs/Grains.Specs.csproj
@@ -8,12 +8,13 @@
 
     <ItemGroup>
         <ProjectReference Include="../Grains/Grains.csproj" />
-        <ProjectReference Include="../Concepts/Concepts.csproj"/>
+        <ProjectReference Include="../Concepts/Concepts.csproj" />
     </ItemGroup>
 
     <ItemGroup>
         <PackageReference Include="OrleansTestKit" />
-        <PackageReference Include="protobuf-net.Grpc"/>
+        <PackageReference Include="protobuf-net.Grpc" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
 
 </Project>
diff --git a/Source/Kernel/Grains/Grains.csproj b/Source/Kernel/Grains/Grains.csproj
index e3aa458ee..c2c4459ee 100644
--- a/Source/Kernel/Grains/Grains.csproj
+++ b/Source/Kernel/Grains/Grains.csproj
@@ -23,5 +23,6 @@
       <PackageReference Include="Microsoft.Orleans.BroadcastChannel" />
       <PackageReference Include="Microsoft.Orleans.Sdk" />
       <PackageReference Include="Microsoft.Orleans.Reminders" />
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Kernel/Projections.Specs/Projections.Specs.csproj b/Source/Kernel/Projections.Specs/Projections.Specs.csproj
index ef9332f29..6a6856606 100644
--- a/Source/Kernel/Projections.Specs/Projections.Specs.csproj
+++ b/Source/Kernel/Projections.Specs/Projections.Specs.csproj
@@ -7,8 +7,12 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../Projections/Projections.csproj"/>
-        <ProjectReference Include="../Concepts/Concepts.csproj"/>
+        <ProjectReference Include="../Projections/Projections.csproj" />
+        <ProjectReference Include="../Concepts/Concepts.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 
 </Project>
diff --git a/Source/Kernel/Server/Server.csproj b/Source/Kernel/Server/Server.csproj
index 599a2f508..1a58e0e11 100644
--- a/Source/Kernel/Server/Server.csproj
+++ b/Source/Kernel/Server/Server.csproj
@@ -35,6 +35,7 @@
         <PackageReference Include="Serilog.Sinks.Console" />
         <PackageReference Include="Serilog.Sinks.PeriodicBatching" />
         <PackageReference Include="Serilog.Sinks.Seq" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
 
     <ItemGroup>
diff --git a/Source/Kernel/Setup/Setup.csproj b/Source/Kernel/Setup/Setup.csproj
index 42c473579..a7cee9dd5 100644
--- a/Source/Kernel/Setup/Setup.csproj
+++ b/Source/Kernel/Setup/Setup.csproj
@@ -7,6 +7,7 @@
     <ItemGroup>
         <PackageReference Include="Microsoft.Orleans.Server" />
         <PackageReference Include="Microsoft.Orleans.Serialization.SystemTextJson" />
+        <PackageReference Include="System.Reactive" />
     </ItemGroup>
 
     <ItemGroup>
diff --git a/Source/Kernel/Storage.MongoDB.Specs/Storage.MongoDB.Specs.csproj b/Source/Kernel/Storage.MongoDB.Specs/Storage.MongoDB.Specs.csproj
index 33b4afe06..0bc424452 100644
--- a/Source/Kernel/Storage.MongoDB.Specs/Storage.MongoDB.Specs.csproj
+++ b/Source/Kernel/Storage.MongoDB.Specs/Storage.MongoDB.Specs.csproj
@@ -7,7 +7,11 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../Storage.MongoDB/Storage.MongoDB.csproj"/>
-        <ProjectReference Include="../Concepts/Concepts.csproj"/>
+        <ProjectReference Include="../Storage.MongoDB/Storage.MongoDB.csproj" />
+        <ProjectReference Include="../Concepts/Concepts.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 </Project>
diff --git a/Source/Kernel/Storage.Specs/Storage.Specs.csproj b/Source/Kernel/Storage.Specs/Storage.Specs.csproj
index e5922db0f..2a4f7f33a 100644
--- a/Source/Kernel/Storage.Specs/Storage.Specs.csproj
+++ b/Source/Kernel/Storage.Specs/Storage.Specs.csproj
@@ -7,8 +7,12 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <ProjectReference Include="../Storage/Storage.csproj"/>
-        <ProjectReference Include="../Concepts/Concepts.csproj"/>
+        <ProjectReference Include="../Storage/Storage.csproj" />
+        <ProjectReference Include="../Concepts/Concepts.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
     </ItemGroup>
 
 </Project>
diff --git a/Source/Kernel/Storage/Storage.csproj b/Source/Kernel/Storage/Storage.csproj
index d7726241d..d7fb70c60 100644
--- a/Source/Kernel/Storage/Storage.csproj
+++ b/Source/Kernel/Storage/Storage.csproj
@@ -10,4 +10,8 @@
             <PrivateAssets>all</PrivateAssets>
         </ProjectReference>
     </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.Reactive" />
+    </ItemGroup>
 </Project>