diff --git a/src/bundles/Elsa.WorkflowServer.Web/Elsa.WorkflowServer.Web.csproj b/src/bundles/Elsa.WorkflowServer.Web/Elsa.WorkflowServer.Web.csproj
index be0b00213..3f6bf4503 100644
--- a/src/bundles/Elsa.WorkflowServer.Web/Elsa.WorkflowServer.Web.csproj
+++ b/src/bundles/Elsa.WorkflowServer.Web/Elsa.WorkflowServer.Web.csproj
@@ -9,6 +9,7 @@
     </PropertyGroup>
 
     <ItemGroup>
+        <ProjectReference Include="..\..\modules\Elsa.EntityFrameworkCore.SqlServer\Elsa.EntityFrameworkCore.SqlServer.csproj" />
         <ProjectReference Include="..\Elsa\Elsa.csproj" />
         <ProjectReference Include="..\..\modules\Elsa.Elasticsearch\Elsa.Elasticsearch.csproj" />
         <ProjectReference Include="..\..\modules\Elsa.Email\Elsa.Email.csproj" />
@@ -34,6 +35,7 @@
     <ItemGroup>
         <PackageReference Include="Azure.Identity" Version="1.8.2" />
         <PackageReference Include="Proto.Persistence.Sqlite" Version="1.1.0" />
+        <PackageReference Include="Proto.Persistence.SqlServer" Version="1.3.1-alpha.0.2" />
     </ItemGroup>
 
 </Project>
diff --git a/src/bundles/Elsa.WorkflowServer.Web/Program.cs b/src/bundles/Elsa.WorkflowServer.Web/Program.cs
index 830b1d970..e6a06c5b8 100644
--- a/src/bundles/Elsa.WorkflowServer.Web/Program.cs
+++ b/src/bundles/Elsa.WorkflowServer.Web/Program.cs
@@ -1,3 +1,4 @@
+using Elsa.EntityFrameworkCore.Extensions;
 using Elsa.EntityFrameworkCore.Modules.Identity;
 using Elsa.EntityFrameworkCore.Modules.Management;
 using Elsa.EntityFrameworkCore.Modules.Runtime;
@@ -10,9 +11,11 @@ using Elsa.MongoDb.Modules.Runtime;
 using Elsa.WorkflowServer.Web;
 using Microsoft.Data.Sqlite;
 using Proto.Persistence.Sqlite;
+using Proto.Persistence.SqlServer;
 
 const bool useMongoDb = false;
-const bool useProtoActor = false;
+const bool useSqlServer = true;
+const bool useProtoActor = true;
 const bool useHangfire = false;
 
 var builder = WebApplication.CreateBuilder(args);
@@ -21,6 +24,7 @@ var configuration = builder.Configuration;
 var identitySection = configuration.GetSection("Identity");
 var identityTokenSection = identitySection.GetSection("Tokens");
 var sqliteConnectionString = configuration.GetConnectionString("Sqlite");
+var sqlServerConnectionString = configuration.GetConnectionString("SqlServer");
 var mongoDbConnectionString = configuration.GetConnectionString("MongoDb")!;
 
 // Add Elsa services.
@@ -43,7 +47,13 @@ services
                 if(useMongoDb)
                     identity.UseMongoDb();
                 else
-                    identity.UseEntityFrameworkCore();
+                    identity.UseEntityFrameworkCore(ef =>
+                    {
+                        if(useSqlServer)
+                            ef.UseSqlServer(sqlServerConnectionString!);
+                        else
+                            ef.UseSqlite(sqliteConnectionString);
+                    });
                 
                 identity.IdentityOptions = options => identitySection.Bind(options);
                 identity.TokenOptions = options => identityTokenSection.Bind(options);
@@ -57,7 +67,13 @@ services
                 if(useMongoDb)
                     management.UseMongoDb();
                 else
-                    management.UseEntityFrameworkCore();
+                    management.UseEntityFrameworkCore(ef =>
+                    {
+                        if(useSqlServer)
+                            ef.UseSqlServer(sqlServerConnectionString!);
+                        else
+                            ef.UseSqlite(sqliteConnectionString);
+                    });
                 
                 management.AddVariableType<ApiResponse<User>>("Api");
                 management.AddVariableType<User>("Api");
@@ -68,17 +84,37 @@ services
                 if(useMongoDb)
                     runtime.UseMongoDb();
                 else
-                    runtime.UseEntityFrameworkCore();
+                    runtime.UseEntityFrameworkCore(ef =>
+                    {
+                        if(useSqlServer)
+                            ef.UseSqlServer(sqlServerConnectionString!);
+                        else
+                            ef.UseSqlite(sqliteConnectionString);
+                    });
                 
                 if(useProtoActor)
-                    runtime.UseProtoActor(proto => proto.PersistenceProvider = _ => new SqliteProvider(new SqliteConnectionStringBuilder(sqliteConnectionString)));
+                {
+                    runtime.UseProtoActor(proto => proto.PersistenceProvider = _ =>
+                    {
+                        if(useSqlServer)
+                            return new SqlServerProvider(sqlServerConnectionString!, true, "", "proto_actor");
+                        else
+                            return new SqliteProvider(new SqliteConnectionStringBuilder(sqliteConnectionString));
+                    });
+                }
                 else
                     runtime.UseDefaultRuntime(dr =>
                     {
                         if(useMongoDb)
                             dr.UseMongoDb();
                         else
-                            dr.UseEntityFrameworkCore();
+                            dr.UseEntityFrameworkCore(ef =>
+                            {
+                                if(useSqlServer)
+                                    ef.UseSqlServer(sqlServerConnectionString!);
+                                else
+                                    ef.UseSqlite(sqliteConnectionString);
+                            });
                     });
                 
                 runtime.UseExecutionLogRecords(e =>
@@ -86,7 +122,13 @@ services
                     if(useMongoDb)
                         e.UseMongoDb();
                     else
-                        e.UseEntityFrameworkCore();
+                        e.UseEntityFrameworkCore(ef =>
+                        {
+                            if(useSqlServer)
+                                ef.UseSqlServer(sqlServerConnectionString!);
+                            else
+                                ef.UseSqlite(sqliteConnectionString);
+                        });
                 });
                 runtime.UseMassTransitDispatcher();
                 
diff --git a/src/modules/Elsa.EntityFrameworkCore.SqlServer/Modules/Runtime/Extensions.cs b/src/modules/Elsa.EntityFrameworkCore.SqlServer/Modules/Runtime/Extensions.cs
index 4569c45d3..268e3ac7e 100644
--- a/src/modules/Elsa.EntityFrameworkCore.SqlServer/Modules/Runtime/Extensions.cs
+++ b/src/modules/Elsa.EntityFrameworkCore.SqlServer/Modules/Runtime/Extensions.cs
@@ -6,6 +6,12 @@ namespace Elsa.EntityFrameworkCore.Extensions;
 
 public static partial class Extensions
 {
+    public static EFCoreWorkflowRuntimePersistenceFeature UseSqlServer(this EFCoreWorkflowRuntimePersistenceFeature feature, string connectionString, ElsaDbContextOptions? options = default)
+    {
+        feature.DbContextOptionsBuilder = (_, db) => db.UseElsaSqlServer(connectionString, options);
+        return feature;
+    }
+    
     public static EFCoreDefaultWorkflowRuntimePersistenceFeature UseSqlServer(this EFCoreDefaultWorkflowRuntimePersistenceFeature feature, string connectionString, ElsaDbContextOptions? options = default)
     {
         feature.DbContextOptionsBuilder = (_, db) => db.UseElsaSqlServer(connectionString, options);
diff --git a/src/modules/Elsa.EntityFrameworkCore.Sqlite/Modules/Runtime/Extensions.cs b/src/modules/Elsa.EntityFrameworkCore.Sqlite/Modules/Runtime/Extensions.cs
index f09a371f1..6cd791f83 100644
--- a/src/modules/Elsa.EntityFrameworkCore.Sqlite/Modules/Runtime/Extensions.cs
+++ b/src/modules/Elsa.EntityFrameworkCore.Sqlite/Modules/Runtime/Extensions.cs
@@ -11,8 +11,8 @@ public static partial class Extensions
     {
         feature.DbContextOptionsBuilder = (_, db) => db.UseElsaSqlite(connectionString, options);
         return feature;
-        
     }
+    
     public static EFCoreDefaultWorkflowRuntimePersistenceFeature UseSqlite(this EFCoreDefaultWorkflowRuntimePersistenceFeature feature, string connectionString = Constants.DefaultConnectionString, ElsaDbContextOptions? options = default)
     {
         feature.DbContextOptionsBuilder = (_, db) => db.UseElsaSqlite(connectionString, options);
diff --git a/src/modules/Elsa.ProtoActor/Elsa.ProtoActor.csproj b/src/modules/Elsa.ProtoActor/Elsa.ProtoActor.csproj
index 0f0bdc5d0..f14653f74 100644
--- a/src/modules/Elsa.ProtoActor/Elsa.ProtoActor.csproj
+++ b/src/modules/Elsa.ProtoActor/Elsa.ProtoActor.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-    <Import Project="..\..\..\common.props" />
-    <Import Project="..\..\..\configureawait.props" />
+    <Import Project="..\..\..\common.props"/>
+    <Import Project="..\..\..\configureawait.props"/>
 
     <PropertyGroup>
         <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
@@ -12,31 +12,35 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="Google.Protobuf" Version="3.23.4" />
+        <PackageReference Include="Google.Protobuf" Version="3.23.4"/>
         <PackageReference Include="Grpc.Tools" Version="2.51.0">
             <PrivateAssets>all</PrivateAssets>
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
         </PackageReference>
-        <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="7.0.0" />
+        <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="7.0.0"/>
     </ItemGroup>
 
     <ItemGroup Label="ProtoActor">
-        <PackageReference Include="Proto.Actor" Version="1.3.0" />
-        <PackageReference Include="Proto.Cluster" Version="1.3.0" />
-        <PackageReference Include="Proto.Cluster.CodeGen" Version="1.3.0" />
-        <PackageReference Include="Proto.Cluster.TestProvider" Version="1.3.0" />
-        <PackageReference Include="Proto.Persistence" Version="1.3.0" />
-        <PackageReference Include="Proto.Remote" Version="1.3.0" />
+        <PackageReference Include="Proto.Actor" Version="1.3.0"/>
+        <PackageReference Include="Proto.Cluster" Version="1.3.0"/>
+        <PackageReference Include="Proto.Cluster.CodeGen" Version="1.3.0"/>
+        <PackageReference Include="Proto.Cluster.TestProvider" Version="1.3.0"/>
+        <PackageReference Include="Proto.Persistence" Version="1.3.0"/>
+        <PackageReference Include="Proto.Remote" Version="1.3.0"/>
     </ItemGroup>
 
     <ItemGroup>
-        <ProjectReference Include="..\Elsa.Workflows.Core\Elsa.Workflows.Core.csproj" />
-        <ProjectReference Include="..\Elsa.Workflows.Runtime\Elsa.Workflows.Runtime.csproj" />
+        <ProjectReference Include="..\Elsa.Workflows.Core\Elsa.Workflows.Core.csproj"/>
+        <ProjectReference Include="..\Elsa.Workflows.Runtime\Elsa.Workflows.Runtime.csproj"/>
     </ItemGroup>
 
-    <ItemGroup Label="Protos">
-        <Protobuf Include="Protos\Messages.proto" />
-        <ProtoGrain Include="Protos\Grains.proto" AdditionalImportDirs="Protos" />
+    <ItemGroup Label="Proto">
+        <Protobuf Include="Proto\Shared.proto" AdditionalImportDirs="./Proto"/>
+        <Protobuf Include="Proto\RunningWorkflows.Messages.proto" AdditionalImportDirs="./Proto"/>
+        <Protobuf Include="Proto\WorkflowInstance.Messages.proto" AdditionalImportDirs="./Proto"/>
+        <ProtoGrain Include="Proto\RunningWorkflows.proto" AdditionalImportDirs="./Proto"/>
+        <ProtoGrain Include="Proto\WorkflowInstance.proto" AdditionalImportDirs="./Proto"/>
     </ItemGroup>
 
+
 </Project>
diff --git a/src/modules/Elsa.ProtoActor/Extensions/ClusterExtensions.cs b/src/modules/Elsa.ProtoActor/Extensions/ClusterExtensions.cs
index 2613d3fdc..b13bcf4a2 100644
--- a/src/modules/Elsa.ProtoActor/Extensions/ClusterExtensions.cs
+++ b/src/modules/Elsa.ProtoActor/Extensions/ClusterExtensions.cs
@@ -1,5 +1,5 @@
 using Elsa.ProtoActor.Grains;
-using Elsa.ProtoActor.Protos;
+using Elsa.ProtoActor.ProtoBuf;
 using Proto.Cluster;
 
 // ReSharper disable once CheckNamespace
@@ -7,6 +7,6 @@ namespace Elsa.Extensions;
 
 internal static class ClusterExtensions
 {
-    public static RunningWorkflowsGrainClient GetNamedRunningWorkflowsGrain(this Cluster cluster) => cluster.GetRunningWorkflowsGrain(nameof(RunningWorkflowsGrain));
-    public static WorkflowGrainClient GetNamedWorkflowGrain(this Cluster cluster, string workflowInstanceId) => cluster.GetWorkflowGrain($"{nameof(WorkflowGrain)}-{workflowInstanceId}");
+    public static RunningWorkflowsClient GetNamedRunningWorkflowsGrain(this Cluster cluster) => cluster.GetRunningWorkflows(nameof(RunningWorkflows));
+    public static WorkflowInstanceClient GetNamedWorkflowGrain(this Cluster cluster, string workflowInstanceId) => cluster.GetWorkflowInstance($"{nameof(WorkflowInstance)}-{workflowInstanceId}");
 }
\ No newline at end of file
diff --git a/src/modules/Elsa.ProtoActor/Extensions/ProtoInputExtensions.cs b/src/modules/Elsa.ProtoActor/Extensions/ProtoInputExtensions.cs
index abdfb3a32..2c85267f7 100644
--- a/src/modules/Elsa.ProtoActor/Extensions/ProtoInputExtensions.cs
+++ b/src/modules/Elsa.ProtoActor/Extensions/ProtoInputExtensions.cs
@@ -1,5 +1,5 @@
 using System.Text.Json;
-using Elsa.ProtoActor.Protos;
+using Elsa.ProtoActor.ProtoBuf;
 using Elsa.Workflows.Core.Serialization.Converters;
 
 namespace Elsa.ProtoActor.Extensions;
diff --git a/src/modules/Elsa.ProtoActor/Features/ProtoActorFeature.cs b/src/modules/Elsa.ProtoActor/Features/ProtoActorFeature.cs
index 9294788cc..b9f0278e8 100644
--- a/src/modules/Elsa.ProtoActor/Features/ProtoActorFeature.cs
+++ b/src/modules/Elsa.ProtoActor/Features/ProtoActorFeature.cs
@@ -5,7 +5,7 @@ using Elsa.Features.Services;
 using Elsa.ProtoActor.Grains;
 using Elsa.ProtoActor.HostedServices;
 using Elsa.ProtoActor.Mappers;
-using Elsa.ProtoActor.Protos;
+using Elsa.ProtoActor.ProtoBuf;
 using Elsa.ProtoActor.Services;
 using Elsa.Workflows.Core.Features;
 using Elsa.Workflows.Runtime.Features;
@@ -95,8 +95,8 @@ public class ProtoActorFeature : FeatureBase
 
             var clusterProvider = ClusterProvider(sp);
             var system = new ActorSystem(systemConfig).WithServiceProvider(sp);
-            var workflowGrainProps = system.DI().PropsFor<WorkflowGrainActor>();
-            var workflowRegistryGrainProps = system.DI().PropsFor<RunningWorkflowsGrainActor>();
+            var workflowGrainProps = system.DI().PropsFor<WorkflowInstanceActor>();
+            var workflowRegistryGrainProps = system.DI().PropsFor<RunningWorkflowsActor>();
 
             var clusterConfig = ClusterConfig
                     .Setup(ClusterName, clusterProvider, new PartitionIdentityLookup())
@@ -104,8 +104,8 @@ public class ProtoActorFeature : FeatureBase
                     .WithActorRequestTimeout(TimeSpan.FromHours(1))
                     .WithActorActivationTimeout(TimeSpan.FromHours(1))
                     .WithActorSpawnVerificationTimeout(TimeSpan.FromHours(1))
-                    .WithClusterKind(WorkflowGrainActor.Kind, workflowGrainProps)
-                    .WithClusterKind(RunningWorkflowsGrainActor.Kind, workflowRegistryGrainProps)
+                    .WithClusterKind(WorkflowInstanceActor.Kind, workflowGrainProps)
+                    .WithClusterKind(RunningWorkflowsActor.Kind, workflowRegistryGrainProps)
                 ;
 
             ActorSystemConfig(sp, systemConfig);
@@ -143,8 +143,8 @@ public class ProtoActorFeature : FeatureBase
 
         // Actors.
         services
-            .AddTransient(sp => new WorkflowGrainActor((context, _) => ActivatorUtilities.CreateInstance<WorkflowGrain>(sp, context)))
-            .AddTransient(sp => new RunningWorkflowsGrainActor((context, _) => ActivatorUtilities.CreateInstance<RunningWorkflowsGrain>(sp, context)))
+            .AddTransient(sp => new WorkflowInstanceActor((context, _) => ActivatorUtilities.CreateInstance<WorkflowInstance>(sp, context)))
+            .AddTransient(sp => new RunningWorkflowsActor((context, _) => ActivatorUtilities.CreateInstance<RunningWorkflows>(sp, context)))
             ;
     }
 
@@ -154,6 +154,6 @@ public class ProtoActorFeature : FeatureBase
 
     private static GrpcNetRemoteConfig CreateDefaultRemoteConfig(IServiceProvider serviceProvider) =>
         GrpcNetRemoteConfig.BindToLocalhost()
-            .WithProtoMessages(MessagesReflection.Descriptor)
+            .WithProtoMessages(SharedReflection.Descriptor)
             .WithProtoMessages(EmptyReflection.Descriptor);
 }
\ No newline at end of file
diff --git a/src/modules/Elsa.ProtoActor/Grains/RunningWorkflowsGrain.cs b/src/modules/Elsa.ProtoActor/Grains/RunningWorkflows.cs
similarity index 76%
rename from src/modules/Elsa.ProtoActor/Grains/RunningWorkflowsGrain.cs
rename to src/modules/Elsa.ProtoActor/Grains/RunningWorkflows.cs
index 6dc887b1a..966b7de9e 100644
--- a/src/modules/Elsa.ProtoActor/Grains/RunningWorkflowsGrain.cs
+++ b/src/modules/Elsa.ProtoActor/Grains/RunningWorkflows.cs
@@ -1,5 +1,6 @@
 using Elsa.ProtoActor.Extensions;
-using Elsa.ProtoActor.Protos;
+using Elsa.ProtoActor.Models;
+using Elsa.ProtoActor.ProtoBuf;
 using Proto;
 using Proto.Cluster;
 using Proto.Persistence;
@@ -7,19 +8,18 @@ using Proto.Persistence.SnapshotStrategies;
 
 namespace Elsa.ProtoActor.Grains;
 
-// TODO: Replace this grain with a store-based implementation that stores metrics.
 /// <summary>
 /// Represents a registry of workflow instances for a given workflow definition version.
 /// </summary>
-public class RunningWorkflowsGrain : RunningWorkflowsGrainBase
+public class RunningWorkflows : RunningWorkflowsBase
 {
-    private const int EventsPerSnapshot = 100;
+    private const int EventsPerSnapshot = 1;
     private readonly Persistence _persistence;
-    private IDictionary<string, WorkflowInstanceEntry> _lookupByInstanceId = new Dictionary<string, WorkflowInstanceEntry>();
-    private IDictionary<string, WorkflowInstanceEntry> _lookupByCorrelationId = new Dictionary<string, WorkflowInstanceEntry>();
+    private IDictionary<string, RunningWorkflowInstanceEntry> _lookupByInstanceId = new Dictionary<string, RunningWorkflowInstanceEntry>();
+    private IDictionary<string, RunningWorkflowInstanceEntry> _lookupByCorrelationId = new Dictionary<string, RunningWorkflowInstanceEntry>();
 
     /// <inheritdoc />
-    public RunningWorkflowsGrain(IProvider provider, IContext context) : base(context)
+    public RunningWorkflows(IProvider provider, IContext context) : base(context)
     {
         _persistence = Persistence.WithEventSourcingAndSnapshotting(
             provider, 
@@ -31,6 +31,12 @@ public class RunningWorkflowsGrain : RunningWorkflowsGrainBase
             GetState);
     }
 
+    /// <inheritdoc />
+    public override async Task OnStarted()
+    {
+        await _persistence.RecoverStateAsync();
+    }
+
     /// <inheritdoc />
     public override async Task Register(RegisterRunningWorkflowRequest request) => await _persistence.PersistRollingEventAsync(request, EventsPerSnapshot);
 
@@ -58,7 +64,7 @@ public class RunningWorkflowsGrain : RunningWorkflowsGrainBase
     
     private void ApplySnapshot(Snapshot snapshot)
     {
-        var registrySnapshot = (WorkflowRegistrySnapshot)snapshot.State;
+        var registrySnapshot = (RunningWorkflowsSnapshot)snapshot.State;
         _lookupByCorrelationId = registrySnapshot.Entries.Where(x => !string.IsNullOrEmpty(x.CorrelationId)).ToDictionary(x => x.CorrelationId!);
         _lookupByInstanceId = registrySnapshot.Entries.ToDictionary(x => x.InstanceId);
     }
@@ -76,11 +82,11 @@ public class RunningWorkflowsGrain : RunningWorkflowsGrainBase
         }
     }
 
-    private object GetState() => new WorkflowRegistrySnapshot(_lookupByInstanceId.Values);
+    private object GetState() => new RunningWorkflowsSnapshot(_lookupByInstanceId.Values.ToList());
     
     private void RegisterInternal(RegisterRunningWorkflowRequest request)
     {
-        var entry = new WorkflowInstanceEntry(request.DefinitionId, request.Version, request.InstanceId, request.CorrelationId);
+        var entry = new RunningWorkflowInstanceEntry(request.DefinitionId, request.Version, request.InstanceId, request.CorrelationId);
         _lookupByInstanceId[request.InstanceId] = entry;
 
         if (!string.IsNullOrEmpty(request.CorrelationId))
@@ -96,6 +102,4 @@ public class RunningWorkflowsGrain : RunningWorkflowsGrainBase
         
         _lookupByInstanceId.Remove(request.InstanceId);
     }
-}
-
-internal record WorkflowInstanceEntry(string DefinitionId, int Version, string InstanceId, string? CorrelationId);
\ No newline at end of file
+}
\ No newline at end of file
diff --git a/src/modules/Elsa.ProtoActor/Grains/WorkflowGrain.cs b/src/modules/Elsa.ProtoActor/Grains/WorkflowInstance.cs
similarity index 97%
rename from src/modules/Elsa.ProtoActor/Grains/WorkflowGrain.cs
rename to src/modules/Elsa.ProtoActor/Grains/WorkflowInstance.cs
index ba6dc4c8f..e32c2e17d 100644
--- a/src/modules/Elsa.ProtoActor/Grains/WorkflowGrain.cs
+++ b/src/modules/Elsa.ProtoActor/Grains/WorkflowInstance.cs
@@ -1,7 +1,8 @@
 using Elsa.Common.Models;
+using Elsa.Extensions;
 using Elsa.ProtoActor.Extensions;
 using Elsa.ProtoActor.Mappers;
-using Elsa.ProtoActor.Protos;
+using Elsa.ProtoActor.ProtoBuf;
 using Elsa.Workflows.Core.Contracts;
 using Elsa.Workflows.Core.State;
 using Elsa.Workflows.Management.Contracts;
@@ -11,14 +12,14 @@ using Proto.Cluster;
 using Proto.Persistence;
 using Exception = System.Exception;
 using WorkflowStatus = Elsa.Workflows.Core.WorkflowStatus;
-using ProtoBookmark = Elsa.ProtoActor.Protos.Bookmark;
+using ProtoBookmark = Elsa.ProtoActor.ProtoBuf.Bookmark;
 
 namespace Elsa.ProtoActor.Grains;
 
 /// <summary>
 /// Executes a workflow.
 /// </summary>
-internal class WorkflowGrain : WorkflowGrainBase
+internal class WorkflowInstance : WorkflowInstanceBase
 {
     private const int MaxSnapshotsToKeep = 5;
     private readonly IWorkflowDefinitionService _workflowDefinitionService;
@@ -38,7 +39,7 @@ internal class WorkflowGrain : WorkflowGrainBase
     private WorkflowState _workflowState = default!;
 
     /// <inheritdoc />
-    public WorkflowGrain(
+    public WorkflowInstance(
         IWorkflowDefinitionService workflowDefinitionService,
         IWorkflowHostFactory workflowHostFactory,
         IWorkflowStateSerializer workflowStateSerializer,
@@ -140,7 +141,7 @@ internal class WorkflowGrain : WorkflowGrainBase
         var startWorkflowOptions = new StartWorkflowHostOptions(instanceId, correlationId, input, request.TriggerActivityId);
         await _workflowHost.StartWorkflowAsync(startWorkflowOptions, cancellationToken);
         var workflowState = _workflowHost.WorkflowState;
-        var result = workflowState.Status == WorkflowStatus.Finished ? Protos.RunWorkflowResult.Finished : Protos.RunWorkflowResult.Suspended;
+        var result = workflowState.Status == WorkflowStatus.Finished ? ProtoBuf.RunWorkflowResult.Finished : ProtoBuf.RunWorkflowResult.Suspended;
 
         _workflowState = workflowState;
 
@@ -261,7 +262,7 @@ internal class WorkflowGrain : WorkflowGrainBase
             await _persistence.PersistRollingSnapshotAsync(GetState(), MaxSnapshotsToKeep);
     }
 
-    private object GetState() => new WorkflowSnapshot(_definitionId, _instanceId, _version, _workflowState, _input);
+    private object GetState() => new WorkflowSnapshot(_definitionId, _instanceId, _version, _workflowState, _input?.ToDictionary(x => x.Key, x => x.Value));
 
     private async Task<IWorkflowHost> CreateWorkflowHostAsync(string definitionId, VersionOptions versionOptions, CancellationToken cancellationToken)
     {
diff --git a/src/modules/Elsa.ProtoActor/Handlers/StopRunningWorkflows.cs b/src/modules/Elsa.ProtoActor/Handlers/StopRunningWorkflows.cs
index 3e9a8472e..91b6f128a 100644
--- a/src/modules/Elsa.ProtoActor/Handlers/StopRunningWorkflows.cs
+++ b/src/modules/Elsa.ProtoActor/Handlers/StopRunningWorkflows.cs
@@ -1,6 +1,6 @@
 using Elsa.Extensions;
 using Elsa.Mediator.Contracts;
-using Elsa.ProtoActor.Protos;
+using Elsa.ProtoActor.ProtoBuf;
 using Elsa.Workflows.Management.Notifications;
 using JetBrains.Annotations;
 using Proto.Cluster;
diff --git a/src/modules/Elsa.ProtoActor/Handlers/UpdateRunningWorkflows.cs b/src/modules/Elsa.ProtoActor/Handlers/UpdateRunningWorkflows.cs
index eb61a4011..015896fe8 100644
--- a/src/modules/Elsa.ProtoActor/Handlers/UpdateRunningWorkflows.cs
+++ b/src/modules/Elsa.ProtoActor/Handlers/UpdateRunningWorkflows.cs
@@ -2,7 +2,7 @@ using Elsa.Extensions;
 using Elsa.Mediator.Contracts;
 using Elsa.ProtoActor.Extensions;
 using Elsa.ProtoActor.Grains;
-using Elsa.ProtoActor.Protos;
+using Elsa.ProtoActor.ProtoBuf;
 using Elsa.Workflows.Core.Notifications;
 using JetBrains.Annotations;
 using Proto.Cluster;
@@ -11,7 +11,7 @@ using WorkflowStatus = Elsa.Workflows.Core.WorkflowStatus;
 namespace Elsa.ProtoActor.Handlers;
 
 /// <summary>
-/// Updates the <see cref="RunningWorkflowsGrain"/> with running workflow instances.
+/// Updates the <see cref="RunningWorkflows"/> with running workflow instances.
 /// </summary>
 [PublicAPI]
 internal class UpdateRunningWorkflows : INotificationHandler<WorkflowExecuted>
diff --git a/src/modules/Elsa.ProtoActor/Mappers/BookmarkMapper.cs b/src/modules/Elsa.ProtoActor/Mappers/BookmarkMapper.cs
index cf2de23c3..a5b918c5b 100644
--- a/src/modules/Elsa.ProtoActor/Mappers/BookmarkMapper.cs
+++ b/src/modules/Elsa.ProtoActor/Mappers/BookmarkMapper.cs
@@ -1,7 +1,7 @@
 using Elsa.ProtoActor.Extensions;
 using Elsa.Workflows.Core.Contracts;
 using Elsa.Workflows.Core.Models;
-using ProtoBookmark = Elsa.ProtoActor.Protos.Bookmark;
+using ProtoBookmark = Elsa.ProtoActor.ProtoBuf.Bookmark;
 
 namespace Elsa.ProtoActor.Mappers;
 
diff --git a/src/modules/Elsa.ProtoActor/Mappers/ExceptionMapper.cs b/src/modules/Elsa.ProtoActor/Mappers/ExceptionMapper.cs
index d8c6a4786..68d888ba7 100644
--- a/src/modules/Elsa.ProtoActor/Mappers/ExceptionMapper.cs
+++ b/src/modules/Elsa.ProtoActor/Mappers/ExceptionMapper.cs
@@ -1,5 +1,5 @@
 using Elsa.Workflows.Core.State;
-using ProtoException = Elsa.ProtoActor.Protos.ExceptionState;
+using ProtoException = Elsa.ProtoActor.ProtoBuf.ExceptionState;
 
 namespace Elsa.ProtoActor.Mappers;
 
diff --git a/src/modules/Elsa.ProtoActor/Mappers/WorkflowExecutionResultMapper.cs b/src/modules/Elsa.ProtoActor/Mappers/WorkflowExecutionResultMapper.cs
index ea4f9f98b..f00a87fdf 100644
--- a/src/modules/Elsa.ProtoActor/Mappers/WorkflowExecutionResultMapper.cs
+++ b/src/modules/Elsa.ProtoActor/Mappers/WorkflowExecutionResultMapper.cs
@@ -1,6 +1,6 @@
 using Elsa.ProtoActor.Extensions;
 using Elsa.Workflows.Runtime.Contracts;
-using ProtoWorkflowExecutionResponse = Elsa.ProtoActor.Protos.WorkflowExecutionResponse;
+using ProtoWorkflowExecutionResponse = Elsa.ProtoActor.ProtoBuf.WorkflowExecutionResponse;
 
 namespace Elsa.ProtoActor.Mappers;
 
diff --git a/src/modules/Elsa.ProtoActor/Mappers/WorkflowFaultStateMapper.cs b/src/modules/Elsa.ProtoActor/Mappers/WorkflowFaultStateMapper.cs
index 8fafbc819..a65b3b027 100644
--- a/src/modules/Elsa.ProtoActor/Mappers/WorkflowFaultStateMapper.cs
+++ b/src/modules/Elsa.ProtoActor/Mappers/WorkflowFaultStateMapper.cs
@@ -1,5 +1,5 @@
 using Elsa.Workflows.Core.State;
-using ProtoWorkflowFault = Elsa.ProtoActor.Protos.WorkflowFault;
+using ProtoWorkflowFault = Elsa.ProtoActor.ProtoBuf.WorkflowFault;
 
 namespace Elsa.ProtoActor.Mappers;
 
diff --git a/src/modules/Elsa.ProtoActor/Mappers/WorkflowStatusMapper.cs b/src/modules/Elsa.ProtoActor/Mappers/WorkflowStatusMapper.cs
index b6073fe79..80b599aff 100644
--- a/src/modules/Elsa.ProtoActor/Mappers/WorkflowStatusMapper.cs
+++ b/src/modules/Elsa.ProtoActor/Mappers/WorkflowStatusMapper.cs
@@ -1,5 +1,5 @@
 using Elsa.Workflows.Core;
-using ProtoWorkflowStatus = Elsa.ProtoActor.Protos.WorkflowStatus;
+using ProtoWorkflowStatus = Elsa.ProtoActor.ProtoBuf.WorkflowStatus;
 
 namespace Elsa.ProtoActor.Mappers;
 
diff --git a/src/modules/Elsa.ProtoActor/Mappers/WorkflowSubStatusMapper.cs b/src/modules/Elsa.ProtoActor/Mappers/WorkflowSubStatusMapper.cs
index aa996f33d..8ebdc92ff 100644
--- a/src/modules/Elsa.ProtoActor/Mappers/WorkflowSubStatusMapper.cs
+++ b/src/modules/Elsa.ProtoActor/Mappers/WorkflowSubStatusMapper.cs
@@ -1,5 +1,5 @@
 using Elsa.Workflows.Core;
-using ProtoWorkflowSubStatus = Elsa.ProtoActor.Protos.WorkflowSubStatus;
+using ProtoWorkflowSubStatus = Elsa.ProtoActor.ProtoBuf.WorkflowSubStatus;
 
 namespace Elsa.ProtoActor.Mappers;
 
diff --git a/src/modules/Elsa.ProtoActor/Models/RunningWorkflowInstanceEntry.cs b/src/modules/Elsa.ProtoActor/Models/RunningWorkflowInstanceEntry.cs
new file mode 100644
index 000000000..d0b0d93fa
--- /dev/null
+++ b/src/modules/Elsa.ProtoActor/Models/RunningWorkflowInstanceEntry.cs
@@ -0,0 +1,10 @@
+namespace Elsa.ProtoActor.Models;
+
+/// <summary>
+/// A snapshot of information about a running workflow instance.
+/// </summary>
+/// <param name="DefinitionId">The workflow definition id.</param>
+/// <param name="Version">The workflow definition version.</param>
+/// <param name="InstanceId">The workflow instance ID.</param>
+/// <param name="CorrelationId">The workflow instance correlation ID.</param>
+public record RunningWorkflowInstanceEntry(string DefinitionId, int Version, string InstanceId, string? CorrelationId);
\ No newline at end of file
diff --git a/src/modules/Elsa.ProtoActor/Proto/RunningWorkflows.Messages.proto b/src/modules/Elsa.ProtoActor/Proto/RunningWorkflows.Messages.proto
new file mode 100644
index 000000000..974657bb2
--- /dev/null
+++ b/src/modules/Elsa.ProtoActor/Proto/RunningWorkflows.Messages.proto
@@ -0,0 +1,27 @@
+syntax = "proto3";
+option csharp_namespace = "Elsa.ProtoActor.ProtoBuf";
+package Elsa.ProtoActor.ProtoBuf;
+
+import "google/protobuf/empty.proto";
+import "Shared.proto";
+
+message RegisterRunningWorkflowRequest {
+  string DefinitionId = 1;
+  int32 Version = 2;
+  string InstanceId = 3;
+  optional string CorrelationId = 6;
+}
+
+message UnregisterRunningWorkflowRequest {
+  string InstanceId = 1;
+}
+
+message CountRunningWorkflowsRequest {
+  string DefinitionId = 1;
+  int32 Version = 2;
+  optional string CorrelationId = 3;
+}
+
+message CountRunningWorkflowsResponse {
+  optional int32 Count = 1;
+}
\ No newline at end of file
diff --git a/src/modules/Elsa.ProtoActor/Proto/RunningWorkflows.proto b/src/modules/Elsa.ProtoActor/Proto/RunningWorkflows.proto
new file mode 100644
index 000000000..22bba7b54
--- /dev/null
+++ b/src/modules/Elsa.ProtoActor/Proto/RunningWorkflows.proto
@@ -0,0 +1,13 @@
+syntax = "proto3";
+option csharp_namespace = "Elsa.ProtoActor.ProtoBuf";
+package Elsa.ProtoActor.ProtoBuf;
+
+import "google/protobuf/empty.proto";
+import "Shared.proto";
+import "RunningWorkflows.Messages.proto";
+
+service RunningWorkflows {
+  rpc Register(RegisterRunningWorkflowRequest) returns (google.protobuf.Empty);
+  rpc Unregister(UnregisterRunningWorkflowRequest) returns (google.protobuf.Empty);
+  rpc Count (CountRunningWorkflowsRequest) returns (CountRunningWorkflowsResponse);
+}
\ No newline at end of file
diff --git a/src/modules/Elsa.ProtoActor/Proto/Shared.proto b/src/modules/Elsa.ProtoActor/Proto/Shared.proto
new file mode 100644
index 000000000..de2453b4b
--- /dev/null
+++ b/src/modules/Elsa.ProtoActor/Proto/Shared.proto
@@ -0,0 +1,15 @@
+syntax = "proto3";
+option csharp_namespace = "Elsa.ProtoActor.ProtoBuf";
+package Elsa.ProtoActor.ProtoBuf;
+
+import "google/protobuf/empty.proto";
+import "google/protobuf/wrappers.proto";
+
+// Shared.
+message Json {
+  string text = 1;
+}
+
+message Input {
+  map<string, Json> Data = 1;
+}
\ No newline at end of file
diff --git a/src/modules/Elsa.ProtoActor/Protos/Messages.proto b/src/modules/Elsa.ProtoActor/Proto/WorkflowInstance.Messages.proto
similarity index 76%
rename from src/modules/Elsa.ProtoActor/Protos/Messages.proto
rename to src/modules/Elsa.ProtoActor/Proto/WorkflowInstance.Messages.proto
index 11d7f673f..213719c06 100644
--- a/src/modules/Elsa.ProtoActor/Protos/Messages.proto
+++ b/src/modules/Elsa.ProtoActor/Proto/WorkflowInstance.Messages.proto
@@ -1,19 +1,11 @@
 syntax = "proto3";
+option csharp_namespace = "Elsa.ProtoActor.ProtoBuf";
+package Elsa.ProtoActor.ProtoBuf;
+
 import "google/protobuf/empty.proto";
 import "google/protobuf/wrappers.proto";
-package Elsa.ProtoActor.Protos;
-option csharp_namespace = "Elsa.ProtoActor.Protos";
+import "Shared.proto";
 
-// Shared.
-message Json {
-  string text = 1;
-}
-
-message Input {
-  map<string, Json> Data = 1;
-}
-
-// WorkflowGrain.
 message CanStartWorkflowResponse {
   bool CanStart = 1;
 }
@@ -102,26 +94,4 @@ message Bookmark {
   optional bool AutoBurn = 8;
   optional string CallbackMethodName = 9;
   string CreatedAt = 10; // ISO 8601
-}
-
-// RunningWorkflowsGrain.
-message RegisterRunningWorkflowRequest {
-  string DefinitionId = 1;
-  int32 Version = 2;
-  string InstanceId = 3;
-  optional string CorrelationId = 6;
-}
-
-message UnregisterRunningWorkflowRequest {
-  string InstanceId = 1;
-}
-
-message CountRunningWorkflowsRequest {
-  string DefinitionId = 1;
-  int32 Version = 2;
-  optional string CorrelationId = 3;
-}
-
-message CountRunningWorkflowsResponse {
-  optional int32 Count = 1;
 }
\ No newline at end of file
diff --git a/src/modules/Elsa.ProtoActor/Protos/Grains.proto b/src/modules/Elsa.ProtoActor/Proto/WorkflowInstance.proto
similarity index 55%
rename from src/modules/Elsa.ProtoActor/Protos/Grains.proto
rename to src/modules/Elsa.ProtoActor/Proto/WorkflowInstance.proto
index f38d4a901..1e5b533ac 100644
--- a/src/modules/Elsa.ProtoActor/Protos/Grains.proto
+++ b/src/modules/Elsa.ProtoActor/Proto/WorkflowInstance.proto
@@ -1,21 +1,17 @@
 syntax = "proto3";
-
-option csharp_namespace = "Elsa.ProtoActor.Protos";
+option csharp_namespace = "Elsa.ProtoActor.ProtoBuf";
+package Elsa.ProtoActor.ProtoBuf;
 
 import "google/protobuf/empty.proto";
-import "Messages.proto";
+import "google/protobuf/wrappers.proto";
+import "Shared.proto";
+import "WorkflowInstance.Messages.proto";
 
-service WorkflowGrain {
+service WorkflowInstance {
   rpc CanStart (StartWorkflowRequest) returns (CanStartWorkflowResponse);
   rpc Start (StartWorkflowRequest) returns (WorkflowExecutionResponse);
   rpc Stop (Empty) returns (Empty);
   rpc Resume (ResumeWorkflowRequest) returns (WorkflowExecutionResponse);
   rpc ExportState(ExportWorkflowStateRequest) returns (ExportWorkflowStateResponse);
   rpc ImportState(ImportWorkflowStateRequest) returns (ImportWorkflowStateResponse);
-}
-
-service RunningWorkflowsGrain {
-  rpc Register(RegisterRunningWorkflowRequest) returns (google.protobuf.Empty);
-  rpc Unregister(UnregisterRunningWorkflowRequest) returns (google.protobuf.Empty);
-  rpc Count (CountRunningWorkflowsRequest) returns (CountRunningWorkflowsResponse);
 }
\ No newline at end of file
diff --git a/src/modules/Elsa.ProtoActor/Services/ProtoActorWorkflowRuntime.cs b/src/modules/Elsa.ProtoActor/Services/ProtoActorWorkflowRuntime.cs
index 399e87cb3..c7f750a1d 100644
--- a/src/modules/Elsa.ProtoActor/Services/ProtoActorWorkflowRuntime.cs
+++ b/src/modules/Elsa.ProtoActor/Services/ProtoActorWorkflowRuntime.cs
@@ -2,7 +2,7 @@ using Elsa.Common.Models;
 using Elsa.Extensions;
 using Elsa.ProtoActor.Extensions;
 using Elsa.ProtoActor.Mappers;
-using Elsa.ProtoActor.Protos;
+using Elsa.ProtoActor.ProtoBuf;
 using Elsa.Workflows.Core.Contracts;
 using Elsa.Workflows.Core.State;
 using Elsa.Workflows.Management.Contracts;
@@ -11,12 +11,12 @@ using Elsa.Workflows.Runtime.Entities;
 using Elsa.Workflows.Runtime.Filters;
 using Proto.Cluster;
 using Bookmark = Elsa.Workflows.Core.Models.Bookmark;
-using ProtoWorkflowStatus = Elsa.ProtoActor.Protos.WorkflowStatus;
-using ProtoWorkflowSubStatus = Elsa.ProtoActor.Protos.WorkflowSubStatus;
-using ProtoWorkflowFault = Elsa.ProtoActor.Protos.WorkflowFault;
-using ProtoException = Elsa.ProtoActor.Protos.ExceptionState;
-using ProtoWorkflowExecutionResponse = Elsa.ProtoActor.Protos.WorkflowExecutionResponse;
-using ProtoBookmark = Elsa.ProtoActor.Protos.Bookmark;
+using ProtoWorkflowStatus = Elsa.ProtoActor.ProtoBuf.WorkflowStatus;
+using ProtoWorkflowSubStatus = Elsa.ProtoActor.ProtoBuf.WorkflowSubStatus;
+using ProtoWorkflowFault = Elsa.ProtoActor.ProtoBuf.WorkflowFault;
+using ProtoException = Elsa.ProtoActor.ProtoBuf.ExceptionState;
+using ProtoWorkflowExecutionResponse = Elsa.ProtoActor.ProtoBuf.WorkflowExecutionResponse;
+using ProtoBookmark = Elsa.ProtoActor.ProtoBuf.Bookmark;
 
 namespace Elsa.ProtoActor.Services;
 
diff --git a/src/modules/Elsa.ProtoActor/Snapshots.cs b/src/modules/Elsa.ProtoActor/Snapshots.cs
index 5acafc12e..b6c52265f 100644
--- a/src/modules/Elsa.ProtoActor/Snapshots.cs
+++ b/src/modules/Elsa.ProtoActor/Snapshots.cs
@@ -1,8 +1,8 @@
-using Elsa.ProtoActor.Grains;
+using Elsa.ProtoActor.Models;
 using Elsa.Workflows.Core.State;
 
 namespace Elsa.ProtoActor;
 
-internal record WorkflowSnapshot(string DefinitionId, string InstanceId, int Version, WorkflowState WorkflowState, IDictionary<string, object>? Input);
+internal record WorkflowSnapshot(string DefinitionId, string InstanceId, int Version, WorkflowState WorkflowState, Dictionary<string, object>? Input);
 
-internal record WorkflowRegistrySnapshot(ICollection<WorkflowInstanceEntry> Entries);
\ No newline at end of file
+internal record RunningWorkflowsSnapshot(List<RunningWorkflowInstanceEntry> Entries);
\ No newline at end of file
diff --git a/src/samples/aspnet/Elsa.Samples.AspNet.ProtoActorRuntime.AzureContainerApps/Program.cs b/src/samples/aspnet/Elsa.Samples.AspNet.ProtoActorRuntime.AzureContainerApps/Program.cs
index d1ca285a9..9a85fe692 100644
--- a/src/samples/aspnet/Elsa.Samples.AspNet.ProtoActorRuntime.AzureContainerApps/Program.cs
+++ b/src/samples/aspnet/Elsa.Samples.AspNet.ProtoActorRuntime.AzureContainerApps/Program.cs
@@ -3,7 +3,7 @@ using Elsa.EntityFrameworkCore.Modules.Labels;
 using Elsa.EntityFrameworkCore.Modules.Management;
 using Elsa.EntityFrameworkCore.Modules.Runtime;
 using Elsa.Extensions;
-using Elsa.ProtoActor.Protos;
+using Elsa.ProtoActor.ProtoBuf;
 using Google.Protobuf.WellKnownTypes;
 using Microsoft.Data.Sqlite;
 using Proto.Cluster.AzureContainerApps;
@@ -69,7 +69,7 @@ services
                 protoActor.RemoteConfig = _ => GrpcNetRemoteConfig
                     .BindTo(advertisedHost)
                     .WithProtoMessages(EmptyReflection.Descriptor)
-                    .WithProtoMessages(MessagesReflection.Descriptor)
+                    .WithProtoMessages(SharedReflection.Descriptor)
                     .WithLogLevelForDeserializationErrors(LogLevel.Critical)
                     .WithRemoteDiagnostics(true); // required by proto.actor dashboard