Restructure folders in API client and add WorkflowInstances API client

src/clients/Elsa.Api.Client/Activities/FlowSwitch.cs

@@ -1,5 +1,5 @@
 using Elsa.Api.Client.Extensions;
-using Elsa.Api.Client.Models;
+using Elsa.Api.Client.Shared.Models;
 
 namespace Elsa.Api.Client.Activities;
 

src/clients/Elsa.Api.Client/Activities/Flowchart.cs

@@ -1,5 +1,5 @@
 using Elsa.Api.Client.Extensions;
-using Elsa.Api.Client.Models;
+using Elsa.Api.Client.Shared.Models;
 
 namespace Elsa.Api.Client.Activities;
 

src/clients/Elsa.Api.Client/Converters/VersionOptionsJsonConverter.cs

@@ -1,6 +1,6 @@
 using System.Text.Json;
 using System.Text.Json.Serialization;
-using Elsa.Api.Client.Models;
+using Elsa.Api.Client.Shared.Models;
 
 namespace Elsa.Api.Client.Converters;
 

src/clients/Elsa.Api.Client/Converters/VersionOptionsTypeConverter.cs

@@ -1,6 +1,6 @@
 using System.ComponentModel;
 using System.Globalization;
-using Elsa.Api.Client.Models;
+using Elsa.Api.Client.Shared.Models;
 
 namespace Elsa.Api.Client.Converters;
 

src/clients/Elsa.Api.Client/Elsa.Api.Client.csproj

@@ -18,4 +18,8 @@
       <PackageReference Include="Refit.HttpClientFactory" Version="6.3.2" />
     </ItemGroup>
 
+    <ItemGroup>
+      <Folder Include="Shared\Enums\" />
+    </ItemGroup>
+
 </Project>

src/clients/Elsa.Api.Client/Extensions/ActivityExtensions.cs

@@ -1,5 +1,5 @@
 using Elsa.Api.Client.Activities;
-using Elsa.Api.Client.Models;
+using Elsa.Api.Client.Shared.Models;
 
 namespace Elsa.Api.Client.Extensions;
 

src/clients/Elsa.Api.Client/Extensions/DependencyInjectionExtensions.cs

@@ -10,6 +10,7 @@ using Elsa.Api.Client.Resources.StorageDrivers.Contracts;
 using Elsa.Api.Client.Resources.VariableTypes.Contracts;
 using Elsa.Api.Client.Resources.WorkflowActivationStrategies.Contracts;
 using Elsa.Api.Client.Resources.WorkflowDefinitions.Contracts;
+using Elsa.Api.Client.Resources.WorkflowInstances.Contracts;
 using Elsa.Api.Client.Services;
 using JetBrains.Annotations;
 using Microsoft.Extensions.DependencyInjection;
@@ -34,6 +35,7 @@ public static class DependencyInjectionExtensions
         services.AddActivityTypeService();
 
         services.AddApi<IWorkflowDefinitionsApi>(CreateRefitSettings);
+        services.AddApi<IWorkflowInstancesApi>(CreateRefitSettings);
         services.AddApi<IActivityDescriptorsApi>(CreateRefitSettings);
         services.AddApi<IStorageDriversApi>(CreateRefitSettings);
         services.AddApi<IVariableTypesApi>(CreateRefitSettings);

src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Contracts/IWorkflowDefinitionsApi.cs

@@ -1,4 +1,6 @@
 using Elsa.Api.Client.Resources.ActivityDescriptors.Models;
+using Elsa.Api.Client.Resources.ActivityDescriptors.Requests;
+using Elsa.Api.Client.Resources.ActivityDescriptors.Responses;
 using Refit;
 
 namespace Elsa.Api.Client.Resources.ActivityDescriptors.Contracts;

src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Enums/ActivityKind.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.ActivityDescriptors.Models;
+namespace Elsa.Api.Client.Resources.ActivityDescriptors.Enums;
 
 /// <summary>
 /// Represents the kind of an activity, which affects how it is executed.

src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Enums/PortType.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.ActivityDescriptors.Models;
+namespace Elsa.Api.Client.Resources.ActivityDescriptors.Enums;
 
 /// <summary>
 /// The type of a port.

src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Models/ActivityDescriptor.cs

@@ -1,3 +1,5 @@
+using Elsa.Api.Client.Resources.ActivityDescriptors.Enums;
+
 namespace Elsa.Api.Client.Resources.ActivityDescriptors.Models;
 
 /// <summary>

src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Models/Port.cs

@@ -1,3 +1,5 @@
+using Elsa.Api.Client.Resources.ActivityDescriptors.Enums;
+
 namespace Elsa.Api.Client.Resources.ActivityDescriptors.Models;
 
 /// <summary>

src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Requests/ListActivityDescriptorsRequest.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.ActivityDescriptors.Models;
+namespace Elsa.Api.Client.Resources.ActivityDescriptors.Requests;
 
 /// <summary>
 /// Represents a request to list activity descriptors.

src/clients/Elsa.Api.Client/Resources/ActivityDescriptors/Responses/ListActivityDescriptorsResponse.cs

@@ -1,4 +1,6 @@
-namespace Elsa.Api.Client.Resources.ActivityDescriptors.Models;
+using Elsa.Api.Client.Resources.ActivityDescriptors.Models;
+
+namespace Elsa.Api.Client.Resources.ActivityDescriptors.Responses;
 
 /// <summary>
 /// Represents a response from listing activity descriptors.

src/clients/Elsa.Api.Client/Resources/Identity/Contracts/ILoginApi.cs

@@ -1,4 +1,5 @@
-using Elsa.Api.Client.Resources.Identity.Models;
+using Elsa.Api.Client.Resources.Identity.Requests;
+using Elsa.Api.Client.Resources.Identity.Responses;
 using Refit;
 
 namespace Elsa.Api.Client.Resources.Identity.Contracts;

src/clients/Elsa.Api.Client/Resources/Identity/Requests/LoginRequest.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.Identity.Models;
+namespace Elsa.Api.Client.Resources.Identity.Requests;
 
 /// <summary>
 /// Represents a request to log in.

src/clients/Elsa.Api.Client/Resources/Identity/Responses/LoginResponse.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.Identity.Models;
+namespace Elsa.Api.Client.Resources.Identity.Responses;
 
 /// <summary>
 /// The response of logging in.

src/clients/Elsa.Api.Client/Resources/StorageDrivers/Contracts/IStorageDriversApi.cs

@@ -1,4 +1,5 @@
 using Elsa.Api.Client.Resources.StorageDrivers.Models;
+using Elsa.Api.Client.Resources.StorageDrivers.Responses;
 using Refit;
 
 namespace Elsa.Api.Client.Resources.StorageDrivers.Contracts;

src/clients/Elsa.Api.Client/Resources/StorageDrivers/Responses/ListStorageDriversResponse.cs

@@ -1,4 +1,6 @@
-namespace Elsa.Api.Client.Resources.StorageDrivers.Models;
+using Elsa.Api.Client.Resources.StorageDrivers.Models;
+
+namespace Elsa.Api.Client.Resources.StorageDrivers.Responses;
 
 /// <summary>
 /// The response containing the storage drivers.

src/clients/Elsa.Api.Client/Resources/VariableTypes/Contracts/IStorageDriversApi.cs

@@ -1,4 +1,5 @@
 using Elsa.Api.Client.Resources.VariableTypes.Models;
+using Elsa.Api.Client.Resources.VariableTypes.Responses;
 using Refit;
 
 namespace Elsa.Api.Client.Resources.VariableTypes.Contracts;

src/clients/Elsa.Api.Client/Resources/VariableTypes/Responses/ListVariableTypesResponse.cs

@@ -1,4 +1,6 @@
-namespace Elsa.Api.Client.Resources.VariableTypes.Models;
+using Elsa.Api.Client.Resources.VariableTypes.Models;
+
+namespace Elsa.Api.Client.Resources.VariableTypes.Responses;
 
 /// <summary>
 /// A response containing a list of variable types.

src/clients/Elsa.Api.Client/Resources/WorkflowActivationStrategies/Contracts/IStorageDriversApi.cs

@@ -1,5 +1,5 @@
-using Elsa.Api.Client.Models;
 using Elsa.Api.Client.Resources.WorkflowActivationStrategies.Models;
+using Elsa.Api.Client.Shared.Models;
 using Refit;
 
 namespace Elsa.Api.Client.Resources.WorkflowActivationStrategies.Contracts;

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Contracts/IWorkflowDefinitionsApi.cs

@@ -1,6 +1,8 @@
 using System.Net.Mime;
-using Elsa.Api.Client.Models;
 using Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+using Elsa.Api.Client.Resources.WorkflowDefinitions.Requests;
+using Elsa.Api.Client.Resources.WorkflowDefinitions.Responses;
+using Elsa.Api.Client.Shared.Models;
 using JetBrains.Annotations;
 using Refit;
 

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Enums/OrderByWorkflowDefinition.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Enums;
 
 /// <summary>
 /// Defines the order by options for workflow definitions.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Models/WorkflowDefinition.cs

@@ -1,5 +1,5 @@
 using Elsa.Api.Client.Activities;
-using Elsa.Api.Client.Models;
+using Elsa.Api.Client.Shared.Models;
 
 namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
 

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Models/WorkflowDefinitionModel.cs

@@ -6,62 +6,28 @@ namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
 /// <summary>
 /// Represents a serializable workflow definition.
 /// </summary>
-/// <param name="Id"></param>
-/// <param name="DefinitionId"></param>
-/// <param name="Name"></param>
-/// <param name="Description"></param>
-/// <param name="CreatedAt"></param>
-/// <param name="Version"></param>
-/// <param name="Variables"></param>
-/// <param name="Inputs"></param>
-/// <param name="Outputs"></param>
-/// <param name="Outcomes"></param>
-/// <param name="CustomProperties"></param>
-/// <param name="IsReadonly"></param>
-/// <param name="IsLatest"></param>
-/// <param name="IsPublished"></param>
-/// <param name="Options">The type of <c>IWorkflowActivationStrategy</c> to apply when new instances are requested to be created.</param>
-/// <param name="Root"></param>
 [PublicAPI]
-public record WorkflowDefinitionModel(
-    string Id,
-    string DefinitionId,
-    string? Name,
-    string? Description,
-    DateTimeOffset CreatedAt,
-    int Version,
-    Version? ToolVersion,
-    ICollection<VariableDefinition>? Variables,
-    ICollection<InputDefinition>? Inputs,
-    ICollection<OutputDefinition>? Outputs,
-    ICollection<string>? Outcomes,
-    IDictionary<string, object>? CustomProperties,
-    bool IsReadonly,
-    bool IsLatest,
-    bool IsPublished,
-    WorkflowOptions? Options,
-    Activity? Root
-)
+public class WorkflowDefinitionModel
 {
-    /// <inheritdoc />
-    public WorkflowDefinitionModel() : this(
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!,
-        default!)
-    {
-    }
+    public string Id { get; set; } = default!;
+    public string DefinitionId { get; set; } = default!;
+    public string? Name { get; set; }
+    public string? Description { get; set; }
+    public DateTimeOffset CreatedAt { get; set; }
+    public int Version { get; set; }
+    public Version? ToolVersion { get; set; }
+    public ICollection<VariableDefinition>? Variables { get; set; }
+    public ICollection<InputDefinition>? Inputs { get; set; }
+    public ICollection<OutputDefinition>? Outputs { get; set; }
+    public ICollection<string>? Outcomes { get; set; }
+    public IDictionary<string, object>? CustomProperties { get; set; }
+    public bool IsReadonly { get; set; }
+    public bool IsLatest { get; set; }
+    public bool IsPublished { get; set; }
+
+    /// <summary>The type of <c>IWorkflowActivationStrategy</c> to apply when new instances are requested to be created.</summary>
+    public WorkflowOptions? Options { get; set; }
+
+    /// <summary></summary>
+    public Activity? Root { get; set; }
 }

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Requests/BulkDeleteWorkflowDefinitionsRequest.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Requests;
 
 /// <summary>
 /// A request to delete many workflow definitions.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Requests/BulkPublishWorkflowDefinitionsRequest.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Requests;
 
 /// <summary>
 /// A request to publish many workflow definitions.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Requests/BulkRetractWorkflowDefinitionsRequest.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Requests;
 
 /// <summary>
 /// A request to retract many workflow definitions.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Requests/GetWorkflowDefinitionRequest.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Requests;
 
 /// <summary>
 /// Represents a request to get a workflow definition.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Requests/RetractWorkflowDefinitionRequest.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Requests;
 
 /// <summary>
 /// Request to retract a workflow definition.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Requests/SaveWorkflowDefinitionRequest.cs

@@ -1,4 +1,6 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models
+using Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Requests
 {
     /// <summary>
     /// Represents a request to save a workflow definition.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Responses/BulkDeleteWorkflowDefinitionsResponse.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Responses;
 
 /// <summary>
 /// The response from a request to delete workflow definitions.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Responses/BulkPublishWorkflowDefinitionsResponse.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Responses;
 
 /// <summary>
 /// The response from a request to publish workflow definitions.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Responses/BulkRetractWorkflowDefinitionsResponse.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Responses;
 
 /// <summary>
 /// The response from a request to publish workflow definitions.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Responses/CountWorkflowDefinitionsResponse.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Responses;
 
 /// <summary>
 /// A response containing the number of workflow definitions.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Responses/GetIsNameUniqueResponse.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Responses;
 
 /// <summary>
 /// A response containing a value indicating whether a workflow definition name is unique.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Responses/ListWorkflowDefinitionsRequest.cs

@@ -1,7 +1,8 @@
-using Elsa.Api.Client.Models;
+using Elsa.Api.Client.Resources.WorkflowDefinitions.Enums;
+using Elsa.Api.Client.Shared.Models;
 using Refit;
 
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Responses;
 
 /// <summary>
 /// Represents a request to list workflow definitions.
@@ -19,10 +20,16 @@ public class ListWorkflowDefinitionsRequest
     public int? PageSize { get; set; }
 
     /// <summary>
-    /// The IDs of the workflow definitions to filter by.
+    /// The definition IDs of the workflow definitions to filter by.
     /// </summary>
     [Query(CollectionFormat.Multi)]
     public ICollection<string>? DefinitionIds { get; set; }
+    
+    /// <summary>
+    /// The IDs of the workflow definitions to filter by.
+    /// </summary>
+    [Query(CollectionFormat.Multi)]
+    public ICollection<string>? Ids { get; set; }
 
     /// <summary>
     /// The name of the workflow materializer to filter by.

src/clients/Elsa.Api.Client/Resources/WorkflowDefinitions/Responses/ListWorkflowDefinitionsResponse.cs

@@ -1,4 +1,6 @@
-namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+using Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
+
+namespace Elsa.Api.Client.Resources.WorkflowDefinitions.Responses;
 
 /// <summary>
 /// Represents a response from listing workflow definitions.

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Contracts/IWorkflowInstancesApi.cs

@@ -1,3 +1,8 @@
+using Elsa.Api.Client.Resources.WorkflowInstances.Models;
+using Elsa.Api.Client.Resources.WorkflowInstances.Requests;
+using Elsa.Api.Client.Shared.Models;
+using Refit;
+
 namespace Elsa.Api.Client.Resources.WorkflowInstances.Contracts;
 
 /// <summary>
@@ -5,4 +10,25 @@ namespace Elsa.Api.Client.Resources.WorkflowInstances.Contracts;
 /// </summary>
 public interface IWorkflowInstancesApi
 {
+    /// <summary>
+    /// Returns a list of workflow instances.
+    /// </summary>
+    [Get("/workflow-instances")]
+    Task<PagedListResponse<WorkflowInstanceSummary>> ListAsync(ListWorkflowInstancesRequest request, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Deletes a workflow instance.
+    /// </summary>
+    /// <param name="id">The ID of the workflow instance to delete.</param>
+    /// <param name="cancellationToken">The cancellation token.</param>
+    [Delete("/workflow-instances/{id}")]
+    Task DeleteAsync(string id, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Deletes a list of workflow instances.
+    /// </summary>
+    /// <param name="request">The request containing the IDs of the workflow instances to delete.</param>
+    /// <param name="cancellationToken">The cancellation token.</param>
+    [Post("/bulk-actions/delete/workflow-instances/by-id")]
+    Task BulkDeleteAsync(BulkDeleteWorkflowInstancesRequest request, CancellationToken cancellationToken);
 }

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Enums/OrderByWorkflowInstance.cs

@@ -0,0 +1,27 @@
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Enums;
+
+/// <summary>
+/// Defines the order by options for workflow instances.
+/// </summary>
+public enum OrderByWorkflowInstance
+{
+    /// <summary>
+    /// Order by the date the workflow instance was created.
+    /// </summary>
+    Created,
+
+    /// <summary>
+    /// Order by the date the workflow instance was last executed.
+    /// </summary>
+    LastExecuted,
+
+    /// <summary>
+    /// Order by the date the workflow instance was finished.
+    /// </summary>
+    Finished,
+
+    /// <summary>
+    /// Order by the name of the workflow instance.
+    /// </summary>
+    Name
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Enums/WorkflowStatus.cs

@@ -0,0 +1,17 @@
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Enums;
+
+/// <summary>
+/// Represents the current workflow status.
+/// </summary>
+public enum WorkflowStatus
+{
+    /// <summary>
+    /// The workflow is running (although it may be waiting for external stimuli).   
+    /// </summary>
+    Running,
+    
+    /// <summary>
+    /// The workflow completed and is no longer running.
+    /// </summary>
+    Finished
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Enums/WorkflowSubStatus.cs

@@ -0,0 +1,32 @@
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Enums;
+
+/// <summary>
+/// Represents the workflow sub-status.
+/// </summary>
+public enum WorkflowSubStatus
+{
+    /// <summary>
+    /// The workflow is currently executing.   
+    /// </summary>
+    Executing,
+    
+    /// <summary>
+    /// The workflow is currently suspended and waiting for external stimuli to resume.   
+    /// </summary>
+    Suspended,
+    
+    /// <summary>
+    /// The workflow completed successfully.
+    /// </summary>
+    Finished,
+    
+    /// <summary>
+    /// The workflow was cancelled.
+    /// </summary>
+    Cancelled,
+    
+    /// <summary>
+    /// The workflow has faulted.
+    /// </summary>
+    Faulted,
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Models/ActivityExecutionContextState.cs

@@ -0,0 +1,37 @@
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Models;
+
+/// <summary>
+/// A serializable shape of an <c>ActivityExecutionContext</c>.
+/// </summary>
+public class ActivityExecutionContextState
+{
+    /// <summary>
+    /// The ID of the activity instance.
+    /// </summary>
+    public string Id { get; set; } = default!;
+    
+    /// <summary>
+    /// The ID of the parent of the activity instance.
+    /// </summary>
+    public string? ParentContextId { get; set; }
+    
+    /// <summary>
+    /// The node ID of the scheduled activity.
+    /// </summary>
+    public string ScheduledActivityNodeId { get; set; } = default!;
+    
+    /// <summary>
+    /// The node ID of the activity that owns the scheduled activity.
+    /// </summary>
+    public string? OwnerActivityNodeId { get; set; }
+    
+    /// <summary>
+    /// A bag of properties.
+    /// </summary>
+    public IDictionary<string, object> Properties { get; set; } = new Dictionary<string, object>();
+
+    /// <summary>
+    /// The evaluated values of the activity's properties.
+    /// </summary>
+    public IDictionary<string, object>? ActivityState { get; set; }
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Models/Bookmark.cs

@@ -0,0 +1,34 @@
+using System.Text.Json.Serialization;
+using JetBrains.Annotations;
+
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Models;
+
+/// <summary>
+/// A bookmark represents a location in a workflow where the workflow can be resumed at a later time.
+/// </summary>
+/// <param name="Id">The ID of the bookmark.</param>
+/// <param name="Name">The name of the bookmark.</param>
+/// <param name="Hash">The hash of the bookmark.</param>
+/// <param name="Payload">The data associated with the bookmark.</param>
+/// <param name="ActivityNodeId">The ID of the activity node associated with the bookmark.</param>
+/// <param name="ActivityInstanceId">The ID of the activity instance associated with the bookmark.</param>
+/// <param name="AutoBurn">Whether or not the bookmark should be automatically burned.</param>
+/// <param name="CallbackMethodName">The name of the method on the activity class to invoke when the bookmark is resumed.</param>
+[PublicAPI]
+public record Bookmark(
+    string Id,
+    string Name,
+    string Hash,
+    object? Payload,
+    string ActivityNodeId,
+    string ActivityInstanceId,
+    bool AutoBurn = true,
+    string? CallbackMethodName = default
+)
+{
+    /// <inheritdoc />
+    [JsonConstructor]
+    public Bookmark() : this("", "", "", null, "", "")
+    {
+    }
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Models/CompletionCallbackState.cs

@@ -0,0 +1,12 @@
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Models;
+
+public class CompletionCallbackState
+{
+    public CompletionCallbackState()
+    {
+    }
+
+    public string OwnerInstanceId { get; init; } = default!;
+    public string ChildNodeId { get; init; } = default!;
+    public string? MethodName { get; init; } = default!;
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Models/ExceptionState.cs

@@ -0,0 +1,18 @@
+using System.Text.Json.Serialization;
+
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Models;
+
+/// <summary>
+/// A simplified, serializable model representing an exception.
+/// </summary>
+public record ExceptionState(Type Type, string Message, string? StackTrace, ExceptionState? InnerException)
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ExceptionState"/> class.
+    /// </summary>
+    [JsonConstructor]
+    public ExceptionState() : this(default!, default!, default, default)
+    {
+        
+    }
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Models/PersistentVariableState.cs

@@ -0,0 +1,14 @@
+using System.Text.Json.Serialization;
+
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Models;
+
+public class PersistentVariableState
+{
+    [JsonConstructor]
+    public PersistentVariableState()
+    {
+    }
+    
+    public string Name { get; set; } = default!;
+    public string StorageDriverId { get; set; } = default!;
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Models/WorkflowFaultState.cs

@@ -0,0 +1,22 @@
+using System.Text.Json.Serialization;
+using JetBrains.Annotations;
+
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Models;
+
+/// <summary>
+/// Holds information about a workflow fault.
+/// </summary>
+/// <param name="Exception">The exception that occurred</param>
+/// <param name="Message">A description about the fault. Usually the exception message, if there waa an exception.</param>
+/// <param name="FaultedActivityId">The ID of the activity that caused the workflow to fault.</param>
+[PublicAPI]
+public record WorkflowFaultState(ExceptionState? Exception, string Message, string? FaultedActivityId)
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="WorkflowFaultState"/> class.
+    /// </summary>
+    [JsonConstructor]
+    public WorkflowFaultState() : this(default, default!, default)
+    {
+    }
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Models/WorkflowInstance.cs

@@ -0,0 +1,75 @@
+using Elsa.Api.Client.Resources.WorkflowInstances.Enums;
+using Elsa.Api.Client.Shared.Models;
+
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Models;
+
+/// <summary>
+/// Represents a workflow instance.
+/// </summary>
+public class WorkflowInstance : Entity
+{
+    /// <summary>
+    /// The ID of the workflow definition.
+    /// </summary>
+    public string DefinitionId { get; set; } = default!;
+    
+    /// <summary>
+    /// The version ID of the workflow definition.
+    /// </summary>
+    public string DefinitionVersionId { get; set; } = default!;
+    
+    /// <summary>
+    /// The version of the workflow definition.
+    /// </summary>
+    public int Version { get; set; }
+    
+    /// <summary>
+    /// The state of the workflow instance.
+    /// </summary>
+    public WorkflowState WorkflowState { get; set; } = default!;
+    
+    /// <summary>
+    /// The status of the workflow instance.
+    /// </summary>
+    public WorkflowStatus Status { get; set; }
+    
+    /// <summary>
+    /// The sub-status of the workflow instance.
+    /// </summary>
+    public WorkflowSubStatus SubStatus { get; set; }
+    
+    /// <summary>
+    /// The ID of the workflow instance.
+    /// </summary>
+    public string? CorrelationId { get; set; }
+    
+    /// <summary>
+    /// The name of the workflow instance.
+    /// </summary>
+    public string? Name { get; set; }
+    
+    /// <summary>
+    /// The timestamp when the workflow instance was created.
+    /// </summary>
+    public DateTimeOffset CreatedAt { get; set; }
+    
+    /// <summary>
+    /// The timestamp when the workflow instance was last executed.
+    /// </summary>
+    public DateTimeOffset? LastExecutedAt { get; set; }
+    
+    /// <summary>
+    /// The timestamp when the workflow instance was finished.
+    /// </summary>
+    public DateTimeOffset? FinishedAt { get; set; }
+    
+    /// <summary>
+    /// The timestamp when the workflow instance was cancelled.
+    /// </summary>
+    public DateTimeOffset? CancelledAt { get; set; }
+    
+    /// <summary>
+    /// The timestamp when the workflow instance was faulted.
+    /// </summary>
+    public DateTimeOffset? FaultedAt { get; set; }
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Models/WorkflowInstanceSummary.cs

@@ -0,0 +1,50 @@
+using Elsa.Api.Client.Resources.WorkflowInstances.Enums;
+using JetBrains.Annotations;
+
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Models;
+
+/// <summary>
+/// Represents a summary view of a <see cref="WorkflowInstance"/>.
+/// </summary>
+[PublicAPI]
+public record WorkflowInstanceSummary
+{
+    /// <summary>The ID of the workflow instance.</summary>
+    public string Id { get; set; } = default!;
+
+    /// <summary>The ID of the workflow definition.</summary>
+    public string DefinitionId { get; set; } = default!;
+
+    /// <summary>The version ID of the workflow definition.</summary>
+    public string DefinitionVersionId { get; set; } = default!;
+
+    /// <summary>The version of the workflow definition.</summary>
+    public int Version { get; set; }
+
+    /// <summary>The status of the workflow instance.</summary>
+    public WorkflowStatus Status { get; set; }
+
+    /// <summary>The sub-status of the workflow instance.</summary>
+    public WorkflowSubStatus SubStatus { get; set; }
+
+    /// <summary>The ID of the workflow instance.</summary>
+    public string? CorrelationId { get; set; }
+
+    /// <summary>The name of the workflow instance.</summary>
+    public string? Name { get; set; }
+
+    /// <summary>The timestamp when the workflow instance was created.</summary>
+    public DateTimeOffset CreatedAt { get; set; }
+
+    /// <summary>The timestamp when the workflow instance was last executed.</summary>
+    public DateTimeOffset? LastExecutedAt { get; set; }
+
+    /// <summary>The timestamp when the workflow instance was finished.</summary>
+    public DateTimeOffset? FinishedAt { get; set; }
+
+    /// <summary>The timestamp when the workflow instance was cancelled.</summary>
+    public DateTimeOffset? CancelledAt { get; set; }
+
+    /// <summary>The timestamp when the workflow instance was faulted.</summary>
+    public DateTimeOffset? FaultedAt { get; set; }
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Models/WorkflowState.cs

@@ -0,0 +1,75 @@
+using Elsa.Api.Client.Resources.WorkflowInstances.Enums;
+using Elsa.Api.Client.Shared.Models;
+
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Models;
+
+/// <summary>
+/// Represents the current state of a workflow. 
+/// </summary>
+public class WorkflowState : Entity
+{
+    /// <summary>
+    /// The workflow definition ID.
+    /// </summary>
+    public string DefinitionId { get; set; } = default!;
+    
+    /// <summary>
+    /// The workflow definition version.
+    /// </summary>
+    public int DefinitionVersion { get; set; }
+
+    /// <summary>
+    /// The correlation ID of the workflow, if any.
+    /// </summary>
+    public string? CorrelationId { get; set; }
+
+    /// <summary>
+    /// The status of the workflow.
+    /// </summary>
+    public WorkflowStatus Status { get; set; }
+    
+    /// <summary>
+    /// The sub status of the workflow.
+    /// </summary>
+    public WorkflowSubStatus SubStatus { get; set; }
+
+    /// <summary>
+    /// Collected bookmarks.
+    /// </summary>
+    public ICollection<Bookmark> Bookmarks { get; set; } = new List<Bookmark>();
+
+    /// <summary>
+    /// The serialized workflow state, if any. 
+    /// </summary>
+    public WorkflowFaultState? Fault { get; set; }
+
+    /// <summary>
+    /// A list of callbacks that activities registered in order to be notified when the activities they scheduled complete. 
+    /// </summary>
+    public ICollection<CompletionCallbackState> CompletionCallbacks { get; set; } = new List<CompletionCallbackState>();
+    
+    /// <summary>
+    /// A flattened list of <see cref="ActivityExecutionContextState"/> objects, representing the various active "call stacks" of the workflow.
+    /// </summary>
+    public ICollection<ActivityExecutionContextState> ActivityExecutionContexts { get; set; } = new List<ActivityExecutionContextState>();
+    
+    /// <summary>
+    /// A dictionary of outputs produced by the workflow.
+    /// </summary>
+    public IDictionary<string, object> Output { get; set; } = new Dictionary<string, object>();
+
+    /// <summary>
+    /// A global property bag that contains properties set by application code and/or activities.
+    /// </summary>
+    public IDictionary<string, object> Properties { get; set; } = new Dictionary<string, object>();
+    
+    /// <summary>
+    /// The created time of the workflow.
+    /// </summary>
+    public DateTimeOffset CreatedAt { get; set; }
+    
+    /// <summary>
+    /// The last updated time of the workflow.
+    /// </summary>
+    public DateTimeOffset UpdatedAt { get; set; }
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Requests/BulkDeleteWorkflowInstancesRequest.cs

@@ -0,0 +1,6 @@
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Requests;
+
+public class BulkDeleteWorkflowInstancesRequest
+{
+    public ICollection<string> Ids { get; set; } = default!;
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Requests/ListWorkflowInstancesRequest.cs

@@ -0,0 +1,18 @@
+using Elsa.Api.Client.Resources.WorkflowInstances.Enums;
+using Elsa.Api.Client.Shared.Models;
+
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Requests;
+
+public class ListWorkflowInstancesRequest
+{
+    public int? Page { get; set; }
+    public int? PageSize { get; set; }
+    public string? SearchTerm { get; set; }
+    public string? DefinitionId { get; set; }
+    public string? CorrelationId { get; set; }
+    public int? Version { get; set; }
+    public WorkflowStatus? Status { get; set; }
+    public WorkflowSubStatus? SubStatus { get; set; }
+    public OrderByWorkflowInstance? OrderBy { get; set; }
+    public OrderDirection? OrderDirection { get; set; }
+}

src/clients/Elsa.Api.Client/Resources/WorkflowInstances/Responses/BulkDeleteWorkflowInstancesResponse.cs

@@ -0,0 +1,8 @@
+using System.Text.Json.Serialization;
+
+namespace Elsa.Api.Client.Resources.WorkflowInstances.Responses;
+
+internal class BulkDeleteWorkflowInstancesResponse
+{
+    [JsonPropertyName("deleted")] public int DeletedCount { get; }
+}

src/clients/Elsa.Api.Client/Shared/Models/ActivityDesignerMetadata.cs

@@ -1,6 +1,6 @@
 using System.Text.Json.Serialization;
 
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents designer metadata for an activity.

src/clients/Elsa.Api.Client/Shared/Models/ActivityOutput.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents an output binding for an activity.

src/clients/Elsa.Api.Client/Shared/Models/Case.cs

@@ -1,7 +1,7 @@
 using Elsa.Api.Client.Contracts;
 using Elsa.Api.Client.Expressions;
 
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 public class Case
 {

src/clients/Elsa.Api.Client/Shared/Models/Connection.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents a connection between two activities.

src/clients/Elsa.Api.Client/Shared/Models/Container.cs

@@ -2,7 +2,7 @@ using Elsa.Api.Client.Activities;
 using Elsa.Api.Client.Extensions;
 using Elsa.Api.Client.Resources.WorkflowDefinitions.Models;
 
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents a container activity.

src/clients/Elsa.Api.Client/Shared/Models/Endpoint.cs

@@ -1,6 +1,6 @@
 using System.Text.Json.Serialization;
 
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents a connection between two activities.

src/clients/Elsa.Api.Client/Shared/Models/Entity.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents an entity.

src/clients/Elsa.Api.Client/Shared/Models/HttpStatusCodeCase.cs

@@ -1,6 +1,6 @@
 using Elsa.Api.Client.Activities;
 
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents an expected status code in the FlowSendHttpRequest activity.

src/clients/Elsa.Api.Client/Shared/Models/ListResponse.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents a generic list response that offers a unified format for returning list of things from API endpoints.

src/clients/Elsa.Api.Client/Shared/Models/MemoryReference.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents a reference to a memory block.

src/clients/Elsa.Api.Client/Shared/Models/OrderDirection.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// The order direction.

src/clients/Elsa.Api.Client/Shared/Models/PagedListResponse.cs

@@ -0,0 +1,9 @@
+namespace Elsa.Api.Client.Shared.Models;
+
+/// <summary>
+/// Represents a generic paged list response that offers a unified format for returning paged list of things from API endpoints.
+/// </summary>
+/// <param name="Items">A page of items.</param>
+/// <param name="TotalCount">The total number of items.</param>
+/// <typeparam name="T">The type of the items.</typeparam>
+public record PagedListResponse<T>(ICollection<T> Items, long TotalCount);

src/clients/Elsa.Api.Client/Shared/Models/Position.cs

@@ -1,6 +1,6 @@
 using System.Text.Json.Serialization;
 
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents a position.

src/clients/Elsa.Api.Client/Shared/Models/Size.cs

@@ -1,6 +1,6 @@
 using System.Text.Json.Serialization;
 
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents a size.

src/clients/Elsa.Api.Client/Shared/Models/VersionOptions.cs

@@ -3,7 +3,7 @@ using System.Text.Json.Serialization;
 using Elsa.Api.Client.Converters;
 using JetBrains.Annotations;
 
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents the version to get.

src/clients/Elsa.Api.Client/Shared/Models/VersionedEntity.cs

@@ -1,4 +1,4 @@
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents an entity that is versioned.

src/clients/Elsa.Api.Client/Shared/Models/WrappedInput.cs

@@ -1,6 +1,6 @@
 using Elsa.Api.Client.Contracts;
 
-namespace Elsa.Api.Client.Models;
+namespace Elsa.Api.Client.Shared.Models;
 
 /// <summary>
 /// Represents an input value for an activity.

src/modules/Elsa.Workflows.Api/Endpoints/WorkflowDefinitions/List/Endpoint.cs

@@ -36,16 +36,16 @@ internal class List : ElsaEndpoint<Request, Response>
 
     private WorkflowDefinitionFilter CreateFilter(Request request)
     {
-        var versionOptions = request.VersionOptions != null ? VersionOptions.FromString(request.VersionOptions) : default(VersionOptions?);
-        var splitIds = request.DefinitionIds ?? Array.Empty<string>();
+        var versionOptions = string.IsNullOrWhiteSpace(request.VersionOptions) ? default(VersionOptions?) : VersionOptions.FromString(request.VersionOptions);
 
-        if (!string.IsNullOrWhiteSpace(request.SearchTerm)) {
-            return new WorkflowDefinitionFilter { SearchTerm = request.SearchTerm, VersionOptions = versionOptions };
-        }
-
-        return splitIds.Any()
-            ? new WorkflowDefinitionFilter { DefinitionIds = splitIds, VersionOptions = versionOptions }
-            : new WorkflowDefinitionFilter { MaterializerName = request.MaterializerName, VersionOptions = versionOptions };
+        return new WorkflowDefinitionFilter
+        {
+            VersionOptions = versionOptions,
+            SearchTerm = request.SearchTerm?.Trim(),
+            MaterializerName = request.MaterializerName,
+            DefinitionIds = request.DefinitionIds,
+            Ids = request.Ids
+        };
     }
 
     private async Task<Page<WorkflowDefinitionSummary>> FindAsync(Request request, WorkflowDefinitionFilter filter, PageArgs pageArgs, CancellationToken cancellationToken)
@@ -58,24 +58,24 @@ internal class List : ElsaEndpoint<Request, Response>
         {
             default:
             {
-                    var order = new WorkflowDefinitionOrder<DateTimeOffset>
-                    {
-                        KeySelector = p => p.CreatedAt,
-                        Direction = direction
-                    };
-
-                    return await _store.FindSummariesAsync(filter, order, pageArgs, cancellationToken);
-                }
-            case OrderByWorkflowDefinition.Name:
+                var order = new WorkflowDefinitionOrder<DateTimeOffset>
                 {
-                    var order = new WorkflowDefinitionOrder<string>
-                    {
-                        KeySelector = p => p.Name ?? string.Empty,
-                        Direction = direction
-                    };
+                    KeySelector = p => p.CreatedAt,
+                    Direction = direction
+                };
 
-                    return await _store.FindSummariesAsync(filter, order, pageArgs, cancellationToken);
-                }
+                return await _store.FindSummariesAsync(filter, order, pageArgs, cancellationToken);
+            }
+            case OrderByWorkflowDefinition.Name:
+            {
+                var order = new WorkflowDefinitionOrder<string>
+                {
+                    KeySelector = p => p.Name ?? string.Empty,
+                    Direction = direction
+                };
+
+                return await _store.FindSummariesAsync(filter, order, pageArgs, cancellationToken);
+            }
             case OrderByWorkflowDefinition.Version:
             {
                 var order = new WorkflowDefinitionOrder<int>

src/modules/Elsa.Workflows.Api/Endpoints/WorkflowDefinitions/List/Models.cs

@@ -9,6 +9,7 @@ internal class Request
 {
     public string? VersionOptions { get; set; }
     public string[]? DefinitionIds { get; set; }
+    public string[]? Ids { get; set; }
     [BindFrom("materializer")] public string? MaterializerName { get; set; }
     [BindFrom("label")] public string[]? Labels { get; set; }
     public int? Page { get; set; }

src/modules/Elsa.Workflows.Core/State/ActivityExecutionContextState.cs

@@ -45,6 +45,4 @@ public class ActivityExecutionContextState
     /// The evaluated values of the activity's properties.
     /// </summary>
     public IDictionary<string, object>? ActivityState { get; set; }
-    
-    //public RegisterState Register { get; set; } = default!;
 }