Initial Release 0.0.1

.github/workflows/dotnet.yml

@@ -5,9 +5,9 @@ name: .NET
 
 on:
   push:
-    branches: [ "main" ]
+    branches: [ "main", "develop" ]
   pull_request:
-    branches: [ "main" ]
+    branches: [ "main", "develop" ]
 
 jobs:
   build:

Coflo.sln

@@ -16,34 +16,44 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Abstractions", "sourc
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "infrastructure", "infrastructure", "{E9952EF9-60A2-441B-BAFB-C285D8ED4761}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Infrastructure.Messaging.RabbitMQ", "source\infrastructure\messaging\Coflo.Infrastructure.Messaging.RabbitMQ\Coflo.Infrastructure.Messaging.RabbitMQ.csproj", "{28F9D028-7AD1-4345-AFCF-13413E5F6250}"
-EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "messaging", "messaging", "{63D82DB8-ADE8-4D8E-A1BC-DB9A29ADCACE}"
-EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "locking", "locking", "{B57221CE-ABE3-420A-8802-C3FF5FD03EAD}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Infrastructure.Locking.Redis", "source\infrastructure\locking\Coflo.Infrastructure.Locking.Redis\Coflo.Infrastructure.Locking.Redis.csproj", "{F7A0F3BB-F8E3-4739-AB71-7704403C8FC8}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "persistance", "persistance", "{B4807B40-63D6-4119-ACE5-8E65EBBFFFAD}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Infrastructure.Persistance.MySQL", "source\infrastructure\persistance\Coflo.Infrastructure.Persistance.MySQL\Coflo.Infrastructure.Persistance.MySQL.csproj", "{C4FA592B-9A2E-4062-8746-D8684ECB545E}"
-EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "hosting", "hosting", "{DEAF9660-31F2-4E6B-9A77-93BA08D7D122}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Hosting.Worker", "source\hosting\Coflo.Hosting.Worker\Coflo.Hosting.Worker.csproj", "{60FE92B2-095B-46C3-8FEC-8C2350E92884}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Hosting.Api.Rest", "source\hosting\Coflo.Hosting.Api.Rest\Coflo.Hosting.Api.Rest.csproj", "{AE88171D-FB16-4686-B23E-1C5F75DF7DC2}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Hosting.Api.GRPC", "source\hosting\Coflo.Hosting.Api.GRPC\Coflo.Hosting.Api.GRPC.csproj", "{47131B79-A7E2-4A46-B9E8-98DDC0C20FCE}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.SDK", "source\core\Coflo.SDK\Coflo.SDK.csproj", "{2569CD34-41EF-42A3-AE63-BE01A0124D44}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Core", "source\core\Coflo.Core\Coflo.Core.csproj", "{2569CD34-41EF-42A3-AE63-BE01A0124D44}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "tests", "tests", "{1230DC9F-E226-4466-B0B1-99B52B66232C}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "core", "core", "{FA4C5E4B-B42D-4BC5-9F26-FD32CD88F75F}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.SDK.Tests", "tests\core\Coflo.SDK.Tests\Coflo.SDK.Tests.csproj", "{7FE22FFD-CB25-446A-9192-76127270C3E1}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Hosting.Orchestrator", "source\hosting\Coflo.Hosting.Orchestrator\Coflo.Hosting.Orchestrator.csproj", "{3009ACF8-F2DC-492C-8E41-7E36AB3A7A6C}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Core.Snowflake", "source\hosting\Coflo.Core.Snowflake\Coflo.Core.Snowflake.csproj", "{2FF4D33E-2964-41B3-B0B2-3C9D70616FBA}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Core.Snowflake.Tests", "tests\core\Coflo.Core.Snowflake.Tests\Coflo.Core.Snowflake.Tests.csproj", "{75110834-EBD6-450A-9092-B619CE02FEAC}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "activities", "activities", "{A4E3E7F1-AA46-4934-90BA-598CE381F0AA}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Activities.Primitives", "source\activities\Coflo.Activities.Primitives\Coflo.Activities.Primitives.csproj", "{CDA31FB1-04BA-4A5D-9282-7EBAB755BE7E}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "hosting", "hosting", "{3DA27C4E-FE4A-4805-BDB7-61BDFFB9B30F}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Hosting.Worker.Tests", "tests\hosting\Coflo.Hosting.Worker.Tests\Coflo.Hosting.Worker.Tests.csproj", "{423ECCA1-DBC1-4947-8BD6-AAF3A8A55B37}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "caching", "caching", "{6F96D4D7-A683-44F1-8BBD-03684B7DF5DD}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Infrastructure.Caching.Redis", "source\infrastructure\caching\Coflo.Infrastructure.Caching.Redis\Coflo.Infrastructure.Caching.Redis.csproj", "{850C0239-46E5-4B2B-BBE8-954C4E93EDB4}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Coflo.Infrastructure.Persistence.Cassandra", "source\infrastructure\persistance\Coflo.Infrastructure.Persistence.Cassandra\Coflo.Infrastructure.Persistence.Cassandra.csproj", "{FFE529A5-CF9D-46F6-9682-A23ED32B6648}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -53,49 +63,38 @@ Global
 		{C46B2D26-B277-4EE0-9497-0473D52EE7A9} = {F514E571-76C3-477F-86F0-3C8CCF512015}
 		{28DE14D7-4F2E-40D9-B847-69866240023D} = {C46B2D26-B277-4EE0-9497-0473D52EE7A9}
 		{E9952EF9-60A2-441B-BAFB-C285D8ED4761} = {F514E571-76C3-477F-86F0-3C8CCF512015}
-		{63D82DB8-ADE8-4D8E-A1BC-DB9A29ADCACE} = {E9952EF9-60A2-441B-BAFB-C285D8ED4761}
-		{28F9D028-7AD1-4345-AFCF-13413E5F6250} = {63D82DB8-ADE8-4D8E-A1BC-DB9A29ADCACE}
 		{B57221CE-ABE3-420A-8802-C3FF5FD03EAD} = {E9952EF9-60A2-441B-BAFB-C285D8ED4761}
 		{F7A0F3BB-F8E3-4739-AB71-7704403C8FC8} = {B57221CE-ABE3-420A-8802-C3FF5FD03EAD}
 		{B4807B40-63D6-4119-ACE5-8E65EBBFFFAD} = {E9952EF9-60A2-441B-BAFB-C285D8ED4761}
-		{C4FA592B-9A2E-4062-8746-D8684ECB545E} = {B4807B40-63D6-4119-ACE5-8E65EBBFFFAD}
 		{DEAF9660-31F2-4E6B-9A77-93BA08D7D122} = {F514E571-76C3-477F-86F0-3C8CCF512015}
 		{60FE92B2-095B-46C3-8FEC-8C2350E92884} = {DEAF9660-31F2-4E6B-9A77-93BA08D7D122}
-		{AE88171D-FB16-4686-B23E-1C5F75DF7DC2} = {DEAF9660-31F2-4E6B-9A77-93BA08D7D122}
-		{47131B79-A7E2-4A46-B9E8-98DDC0C20FCE} = {DEAF9660-31F2-4E6B-9A77-93BA08D7D122}
 		{2569CD34-41EF-42A3-AE63-BE01A0124D44} = {C46B2D26-B277-4EE0-9497-0473D52EE7A9}
 		{FA4C5E4B-B42D-4BC5-9F26-FD32CD88F75F} = {1230DC9F-E226-4466-B0B1-99B52B66232C}
 		{7FE22FFD-CB25-446A-9192-76127270C3E1} = {FA4C5E4B-B42D-4BC5-9F26-FD32CD88F75F}
+		{3009ACF8-F2DC-492C-8E41-7E36AB3A7A6C} = {DEAF9660-31F2-4E6B-9A77-93BA08D7D122}
+		{2FF4D33E-2964-41B3-B0B2-3C9D70616FBA} = {C46B2D26-B277-4EE0-9497-0473D52EE7A9}
+		{75110834-EBD6-450A-9092-B619CE02FEAC} = {FA4C5E4B-B42D-4BC5-9F26-FD32CD88F75F}
+		{A4E3E7F1-AA46-4934-90BA-598CE381F0AA} = {F514E571-76C3-477F-86F0-3C8CCF512015}
+		{CDA31FB1-04BA-4A5D-9282-7EBAB755BE7E} = {A4E3E7F1-AA46-4934-90BA-598CE381F0AA}
+		{3DA27C4E-FE4A-4805-BDB7-61BDFFB9B30F} = {1230DC9F-E226-4466-B0B1-99B52B66232C}
+		{423ECCA1-DBC1-4947-8BD6-AAF3A8A55B37} = {3DA27C4E-FE4A-4805-BDB7-61BDFFB9B30F}
+		{6F96D4D7-A683-44F1-8BBD-03684B7DF5DD} = {E9952EF9-60A2-441B-BAFB-C285D8ED4761}
+		{850C0239-46E5-4B2B-BBE8-954C4E93EDB4} = {6F96D4D7-A683-44F1-8BBD-03684B7DF5DD}
+		{FFE529A5-CF9D-46F6-9682-A23ED32B6648} = {B4807B40-63D6-4119-ACE5-8E65EBBFFFAD}
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
 		{28DE14D7-4F2E-40D9-B847-69866240023D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{28DE14D7-4F2E-40D9-B847-69866240023D}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{28DE14D7-4F2E-40D9-B847-69866240023D}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{28DE14D7-4F2E-40D9-B847-69866240023D}.Release|Any CPU.Build.0 = Release|Any CPU
-		{28F9D028-7AD1-4345-AFCF-13413E5F6250}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{28F9D028-7AD1-4345-AFCF-13413E5F6250}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{28F9D028-7AD1-4345-AFCF-13413E5F6250}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{28F9D028-7AD1-4345-AFCF-13413E5F6250}.Release|Any CPU.Build.0 = Release|Any CPU
 		{F7A0F3BB-F8E3-4739-AB71-7704403C8FC8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{F7A0F3BB-F8E3-4739-AB71-7704403C8FC8}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{F7A0F3BB-F8E3-4739-AB71-7704403C8FC8}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{F7A0F3BB-F8E3-4739-AB71-7704403C8FC8}.Release|Any CPU.Build.0 = Release|Any CPU
-		{C4FA592B-9A2E-4062-8746-D8684ECB545E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{C4FA592B-9A2E-4062-8746-D8684ECB545E}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{C4FA592B-9A2E-4062-8746-D8684ECB545E}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{C4FA592B-9A2E-4062-8746-D8684ECB545E}.Release|Any CPU.Build.0 = Release|Any CPU
 		{60FE92B2-095B-46C3-8FEC-8C2350E92884}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{60FE92B2-095B-46C3-8FEC-8C2350E92884}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{60FE92B2-095B-46C3-8FEC-8C2350E92884}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{60FE92B2-095B-46C3-8FEC-8C2350E92884}.Release|Any CPU.Build.0 = Release|Any CPU
-		{AE88171D-FB16-4686-B23E-1C5F75DF7DC2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{AE88171D-FB16-4686-B23E-1C5F75DF7DC2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{AE88171D-FB16-4686-B23E-1C5F75DF7DC2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{AE88171D-FB16-4686-B23E-1C5F75DF7DC2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{47131B79-A7E2-4A46-B9E8-98DDC0C20FCE}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{47131B79-A7E2-4A46-B9E8-98DDC0C20FCE}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{47131B79-A7E2-4A46-B9E8-98DDC0C20FCE}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{47131B79-A7E2-4A46-B9E8-98DDC0C20FCE}.Release|Any CPU.Build.0 = Release|Any CPU
 		{2569CD34-41EF-42A3-AE63-BE01A0124D44}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{2569CD34-41EF-42A3-AE63-BE01A0124D44}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{2569CD34-41EF-42A3-AE63-BE01A0124D44}.Release|Any CPU.ActiveCfg = Release|Any CPU
@@ -104,5 +103,33 @@ Global
 		{7FE22FFD-CB25-446A-9192-76127270C3E1}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{7FE22FFD-CB25-446A-9192-76127270C3E1}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{7FE22FFD-CB25-446A-9192-76127270C3E1}.Release|Any CPU.Build.0 = Release|Any CPU
+		{3009ACF8-F2DC-492C-8E41-7E36AB3A7A6C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3009ACF8-F2DC-492C-8E41-7E36AB3A7A6C}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3009ACF8-F2DC-492C-8E41-7E36AB3A7A6C}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3009ACF8-F2DC-492C-8E41-7E36AB3A7A6C}.Release|Any CPU.Build.0 = Release|Any CPU
+		{2FF4D33E-2964-41B3-B0B2-3C9D70616FBA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2FF4D33E-2964-41B3-B0B2-3C9D70616FBA}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2FF4D33E-2964-41B3-B0B2-3C9D70616FBA}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2FF4D33E-2964-41B3-B0B2-3C9D70616FBA}.Release|Any CPU.Build.0 = Release|Any CPU
+		{75110834-EBD6-450A-9092-B619CE02FEAC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{75110834-EBD6-450A-9092-B619CE02FEAC}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{75110834-EBD6-450A-9092-B619CE02FEAC}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{75110834-EBD6-450A-9092-B619CE02FEAC}.Release|Any CPU.Build.0 = Release|Any CPU
+		{CDA31FB1-04BA-4A5D-9282-7EBAB755BE7E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CDA31FB1-04BA-4A5D-9282-7EBAB755BE7E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CDA31FB1-04BA-4A5D-9282-7EBAB755BE7E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CDA31FB1-04BA-4A5D-9282-7EBAB755BE7E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{423ECCA1-DBC1-4947-8BD6-AAF3A8A55B37}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{423ECCA1-DBC1-4947-8BD6-AAF3A8A55B37}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{423ECCA1-DBC1-4947-8BD6-AAF3A8A55B37}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{423ECCA1-DBC1-4947-8BD6-AAF3A8A55B37}.Release|Any CPU.Build.0 = Release|Any CPU
+		{850C0239-46E5-4B2B-BBE8-954C4E93EDB4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{850C0239-46E5-4B2B-BBE8-954C4E93EDB4}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{850C0239-46E5-4B2B-BBE8-954C4E93EDB4}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{850C0239-46E5-4B2B-BBE8-954C4E93EDB4}.Release|Any CPU.Build.0 = Release|Any CPU
+		{FFE529A5-CF9D-46F6-9682-A23ED32B6648}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{FFE529A5-CF9D-46F6-9682-A23ED32B6648}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{FFE529A5-CF9D-46F6-9682-A23ED32B6648}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{FFE529A5-CF9D-46F6-9682-A23ED32B6648}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal

README.md

@@ -5,26 +5,19 @@
 ![Discord](https://img.shields.io/discord/1096095159860600832?label=Discord&logo=Discord&style=for-the-badge)
 
 Coflo is an in development, distrobuted workflow engine.
+
 ## Roadmap
 
 - Additional browser support
 
 - Add more integrations
 
-
 ## Run Locally
 
-
-
-
 ## Features
 
-
-
-
 ## Acknowledgements
 
-
 ## Appendix
 
 ## Contributing

source/infrastructure/messaging/Coflo.Infrastructure.Messaging.RabbitMQ/Coflo.Infrastructure.Messaging.RabbitMQ.csproj → source/activities/Coflo.Activities.Primitives/Coflo.Activities.Primitives.csproj

@@ -6,4 +6,8 @@
         <Nullable>enable</Nullable>
     </PropertyGroup>
 
+    <ItemGroup>
+      <ProjectReference Include="..\..\core\Coflo.Core\Coflo.Core.csproj" />
+    </ItemGroup>
+
 </Project>

source/activities/Coflo.Activities.Primitives/Control/If.cs

@@ -0,0 +1,40 @@
+using Coflo.Abstractions.Activities.Attributes;
+using Coflo.Abstractions.Activities.Contracts;
+using Coflo.Abstractions.Activities.Enums;
+using Coflo.Abstractions.Activities.Models;
+using Coflo.Abstractions.Evaluation.Contracts;
+using Coflo.Abstractions.Evaluation.Models;
+using Coflo.Abstractions.Variables.Model;
+
+namespace Coflo.Activities.Primitives.Control;
+
+[Activity(DisplayName = "If", Outcomes = new[] { "True", "False" }, Category = ActivityCategory.Decision)]
+public class If : Activity
+{
+    private readonly IEvaluator _evaluator;
+
+    [ActivityInput(DisplayName = "Condition")]
+    public string Condition { get; set; } = "false";
+
+    public If(IEvaluator evaluator) : base("IF")
+    {
+        _evaluator = evaluator;
+    }
+
+    public override async Task<IActivityExecutionResult> ExecuteAsync(ActivityExecutionContext context)
+    {
+        try
+        {
+            var evaluationContext = new EvaluationContext(context.Variables, Condition);
+            var result = await _evaluator.EvaluateAsync(evaluationContext);
+
+            return new ActivityExecutionResult(result ? "True" : "False", true, ActivityStatus.Completed,
+                new VariableCollection(), context.WorkflowInstanceId, context.ActivityInstanceId);
+        }
+        catch (Exception e)
+        {
+            return new ActivityExecutionResult(string.Empty, false, ActivityStatus.Faulted,
+                new VariableCollection(), context.WorkflowInstanceId, context.ActivityInstanceId);
+        }
+    }
+}

source/activities/Coflo.Activities.Primitives/Variables/SetVariable.cs

@@ -0,0 +1,36 @@
+using Coflo.Abstractions.Activities.Attributes;
+using Coflo.Abstractions.Activities.Contracts;
+using Coflo.Abstractions.Activities.Enums;
+using Coflo.Abstractions.Activities.Models;
+using Coflo.Abstractions.Variables.Model;
+
+namespace Coflo.Activities.Primitives.Variables;
+
+[Activity(DisplayName = "Set Variable", Category = ActivityCategory.Workflow, Outcomes = new[] { Done, Failed })]
+public class SetVariable : Activity
+{
+    private const string Done = "Done";
+    private const string Failed = "Failed";
+
+    [ActivityInput(DisplayName = "Variable")]
+    public VariableDefinition Variable { get; set; }
+
+    [ActivityInput(DisplayName = "Value")]
+    public object? Value { get; set; }
+
+    public SetVariable() : base("SET_VARIABLE")
+    {
+    }
+
+    public override Task<IActivityExecutionResult> ExecuteAsync(ActivityExecutionContext context)
+    {
+        var variable = new VariableInstance(Variable);
+        variable.SetValue(Value);
+        var isUpdated = context.Variables.AddOrUpdate(variable);
+
+        var result = new ActivityExecutionResult(isUpdated ? Done : Failed, isUpdated, ActivityStatus.Completed, context.Variables,
+            context.WorkflowInstanceId, context.ActivityInstanceId);
+
+        return Task.FromResult(result as IActivityExecutionResult);
+    }
+}

source/core/Coflo.Abstractions/Activities/Attributes/ActivityAttribute.cs

@@ -0,0 +1,11 @@
+using Coflo.Abstractions.Activities.Enums;
+
+namespace Coflo.Abstractions.Activities.Attributes;
+
+public class ActivityAttribute : Attribute
+{
+    public string DisplayName { get; set; } = string.Empty;
+    public string Description { get; set; } = string.Empty;
+    public ActivityCategory Category { get; set; } = ActivityCategory.None;
+    public string[] Outcomes { get; set; } = { OutcomeNames.Failure, OutcomeNames.Success };
+}

source/core/Coflo.Abstractions/Activities/Attributes/ActivityInputAttribute.cs

@@ -0,0 +1,7 @@
+namespace Coflo.Abstractions.Activities.Attributes;
+
+[AttributeUsage(AttributeTargets.Property)]
+public class ActivityInputAttribute : Attribute
+{
+    public string DisplayName { get; set; }
+}

source/core/Coflo.Abstractions/Activities/Attributes/ActivityOutputAttribute.cs

@@ -0,0 +1,7 @@
+namespace Coflo.Abstractions.Activities.Attributes;
+
+[AttributeUsage(AttributeTargets.Property)]
+public class ActivityOutputAttribute : Attribute
+{
+    public string DisplayName { get; set; }
+}

source/core/Coflo.Abstractions/Activities/Commands/StartActivityCommand.cs

@@ -0,0 +1,17 @@
+using Coflo.Abstractions.Variables.Model;
+using Mediator;
+
+namespace Coflo.Abstractions.Activities.Commands;
+
+public class StartActivityCommand : ICommand
+{
+    public long WorkflowInstanceId { get; set; }
+    public long ActivityDefinitionId { get; set; }
+    public IVariableCollection VariableCollection { get; set; }
+    public StartActivityCommand(long workflowInstanceId, long activityDefinitionId, IVariableCollection variableCollection)
+    {
+        WorkflowInstanceId = workflowInstanceId;
+        ActivityDefinitionId = activityDefinitionId;
+        VariableCollection = variableCollection;
+    }
+}

source/core/Coflo.Abstractions/Activities/Contracts/IActivity.cs

@@ -0,0 +1,6 @@
+namespace Coflo.Abstractions.Activities.Contracts;
+
+public interface IActivity : IActivityBody
+{
+    public string Name { get; }
+}

source/core/Coflo.Abstractions/Activities/Contracts/IActivityBody.cs

@@ -0,0 +1,8 @@
+using Coflo.Abstractions.Activities.Models;
+
+namespace Coflo.Abstractions.Activities.Contracts;
+
+public interface IActivityBody
+{
+    Task<IActivityExecutionResult> ExecuteAsync(ActivityExecutionContext context);
+}

source/core/Coflo.Abstractions/Activities/Contracts/IActivityExecutionContext.cs

@@ -0,0 +1,11 @@
+using Coflo.Abstractions.Variables.Model;
+
+namespace Coflo.Abstractions.Activities.Contracts;
+
+public interface IActivityExecutionContext
+{
+    public VariableCollection Variables { get; set; }
+    public long WorkflowInstanceId { get; set; }
+    public long ActivityInstanceId { get; set; }
+    public string ActivityName { get; set; }
+}

source/core/Coflo.Abstractions/Activities/Contracts/IActivityExecutionResult.cs

@@ -0,0 +1,14 @@
+using Coflo.Abstractions.Activities.Enums;
+using Coflo.Abstractions.Variables.Model;
+
+namespace Coflo.Abstractions.Activities.Contracts;
+
+public interface IActivityExecutionResult
+{
+    public bool IsSuccessful { get; set; }
+    public ActivityStatus Status { get; set; }
+    public IVariableCollection VariableCollection { get; set; }
+    public long WorkflowInstanceId { get; set; }
+    public long ActivityInstanceId { get; set; }
+    public string Outcome { get; set; }
+}

source/core/Coflo.Abstractions/Activities/Contracts/IActivityInstance.cs

@@ -0,0 +1,14 @@
+using Coflo.Abstractions.Activities.Enums;
+using Coflo.Abstractions.Variables.Model;
+
+namespace Coflo.Abstractions.Activities.Contracts;
+
+public interface IActivityInstance
+{
+    public long WorkflowInstanceId { get; set; }
+    public long ActivityInstanceId { get; set; }
+    public string ActivityName { get; set; }
+    public ActivityInstanceStatus Status { get; set; }
+
+    public VariableCollection VariableCollection { get; set; }
+}