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Workflow Engine: Release Notes


June 25, 2024


  • Fixed several issues with the behavior of the CreateProcess activity.
  • Fixed a bug with SignalR connection.
  • Fixed a bug with plugin list.
  • The braces dependency has been updated from version 3.0.2 to 3.0.3.
  • Updated from version 6.5.4 to 6.5.5 in Workflow-designer-angular.
  • Updated from version 2.5.4 to 2.5.5 in Workflow-designer-angular.
  • Updated ws from version 8.16.0 to 8.17.1 in Workflow-designer-angular.


  • Fixed a bug in subprocesses execution.
  • Updated Npgsql package in OptimaJet.Workflow.PostgreSQL to version 8.0.2.


  • Corrected the GetProcessHistoryCount method in the MongoDB provider.


  • Updated Microsoft.Identity.Client from version 4.60.3 to 4.61.3 in Microsoft SQL WebForm sample.
  • Updated Azure.Identity from version 1.11.3 to 1.11.4 in Microsoft SQL Sample.


May 27, 2024


  • Fixed an issue with saving custom activity.
  • Added the ability to set the schema name in the designer.


  • Added functionality to retrieve a list of all migrations and a list of unapplied migrations.


  • Updated the "Testing workflow schemes" article with corrections related to migrations.


May 13, 2024


  • Removed all .NET Framework 4.8 Samples except for the Microsoft SQL Server Sample.
  • Updated .NET Framework 4.8 Samples to WorkflowEngine 13.0.0.
  • Added Blazor integration Sample.


  • Updated Npgsql driver from version 8.0.2 to 8.0.3.


May 06, 2024

Real-Time Tracking Plugin

  • Implemented a Real-Time Tracking plugin that extends the Workflow Designer with real-time functionality, allowing live updates of process states via SignalR. For more details, refer to the documentation.


  • Introduced the optional capability for automatic migration, allowing the creation and updating of the database schema without manually running scripts. This feature ensures that the Workflow Engine maintains a list of executed scripts accessible within the database.


  • The Workflow Designer can now be initiated directly from the command line using the npx @optimajet/workflow-designer $BackendUrl $SchemeCode command, which automates the fetching and execution of packages from the npm repository. For more details, refer to the documentation.
  • Added an 'About' button to the designer’s menu, displaying both the backend and designer version information to users.

Bug Fixes

  • Corrected an error related to clipboard access in the 'Instance Info' section.
  • The backend now filters events to ensure that Workflow Designer receive only pertinent data. Unknown events are currently ignored.


April 24, 2024


  • Added the ability to drag and resize windows on touch screens.


April 10, 2024


  • Added a new setting InboxCheckConditions, which allows filling the inbox only with commands that satisfy all Conditions.


March 28, 2024


  • Resolved a bug preventing the timer from logging certain exceptions.


  • Providers now utilize PackageReference instead of ProjectReference.
  • Updated Npgsql package in OptimaJet.Workflow.PostgreSQL to version 8.0.2.


  • Updated NetCore Samples to .NET 8.


  • The designer now supports React 18.
  • Updated the designer React sample to React 18.
  • Added functionality to clear the PreExecution Result field in the Decision Table.
  • Fixed a bug in the behavior of the Decision Table regarding transitions.
  • Corrected an issue where Name and State fields were not filled in custom activities.
  • Added the ability to insert a logo into the designer. For more details, refer to the documentation.


  • Included information regarding Supported .NET versions on this page.
  • Updated the description of timers on this page.


March 13, 2024


  • Introducing a new provider for SQLite database integration.
  • Added a new edition for non-commercial use: Workflow Engine Community.

Bug Fixes

  • Corrected timer value validation within the designer.
  • Rectified improper window positioning and movement within the designer.
  • Calibrated z-index values for designer's windows.
  • Resolved compilation errors in the Angular designer package.
  • Fixed SQL Deadlock occurring during ExecuteCommand.
  • Color palette button no longer appears in readonly mode.


February 21, 2024


  • Introducing the new Bulk API for WorkflowRuntime, enabling parallel execution of large arrays of tasks. Access to this API is facilitated through the WorkflowRuntime.Bulk property.


  • Added input validation to the HelperDateTime.GetInterval method. When incorrect values are passed, it now returns a TimeSpan with a zero value.


  • Resolved an issue where default annotation values for custom activities were not persisting in the schema without manual activity data saving.


January 19, 2024


  • Fixed a bug when switching to expert mode for Decision and Decision table.
  • Fixed the error of executing OnSuccessCallback in the designer.create method.
  • Outdated libraries have been replaced.
  • Fixed the Instance info function.
  • Fixed the display after fit to screen for an empty scheme.
  • The follow-redirects dependency has been updated to version 1.15.4.


  • Microsoft.Data.SqlClient has been updated to version 2.1.7 in MSSQL Provider.


December 25, 2023


  • Added a new plugin for working with Active Directory services. For more information, refer to ActiveDirectoryPlugin.


  • Displaying error from custom activities.


  • Fixed a bug with query parameters in MSSQL Provider.


  • Added a base class Deactivated for disabling plugins.
  • The OnPluginRemoveAsync method has been removed from the IWorkflowPlugin interface.


December 04, 2023

Breaking changes

Breaking changes only for MongoDB and Angular packages.

  • MongoDB driver has been updated from 2.10.4 to 2.19.0. If you are using a multi-server mode, you need a MongoDB cluster.
  • Angular designer package has been updated to Angular 17. This requires the Node 18.13.


  • Fixed the operation of parameters with names containing a space.
  • Improved performance of subprocesses execution.


  • Fixed an error displaying parameter types in the Parameters windows.
  • Fixed an error displaying process parameters in the ProcessInfo window.
  • Fixed an error displaying exceptions handling in the Activity window.
  • Improved zoom operation.


  • Angular sample updated to Angular 17.
  • React package is now compatible with React 18.


September 01, 2023


  • Now in the JSON editor and also in other places, JSON.stringify() is always used for formatting instead of JSON5.stringify(), so that the formatted code is always valid JSON.


This release brings a new enhanced feature as well as smoother and richer user experience.

August 28, 2023


Users can now establish their Work Calendars in accordance with specific workdays, thereby preventing any unnecessary Timer activation during non-operational periods. Once you set up your calendar and append the letter <w> to your Interval Timer Value, the system will translate this interval to your established working time, adeptly bypassing non-working hours and holidays. For more information, refer to the Work Calendar documentation.


A bug associated with timer.Value mutation in TimerManagerBase has been fixed. This resolves any issues and exceptions interconnected with the GetCustomTimerValueAsync event and the CreateInstanceAsync method.

Update instruction

The following additional actions must be taken to upgrade to Workflow Engine 11.0.0 from Workflow Engine 10.0.1:


July 13, 2023



July 13, 2023

Please use version 10.0.1 instead of version 10.0.0.



  • The System.Linq.Dynamic.Core dependency has been removed from the MongoDB provider.


June 2, 2023


  • A bug has been fixed in the MongoDB provider, where incorrect entries were being created in ApprovalHistory.


May 24, 2023


  • Now all data from error response is thrown into the onError callbacks of the Designer.load, and others functions.

And other minor improvements and fixes.


May 10, 2023


  • Fixed a bug with moving the selected activity.


May 03, 2023


  • Fixed filling types for custom activities.


April 20, 2023

Breaking changes

  • The Oracle database provider has been updated to netstandard2.1 target framework. The update is due to vulnerabilities found in previous versions of the Oracle.ManagedDataAccess.Core package. This means that the Oracle database provider can no longer be used with the .NET Framework, since netstandard2.1 is not supported on the .NET Framework. If you don't use an Oracle database, this change is not breaking for you.


  • Changes in the procedure for obtaining license and trial keys, you can read more here.


  • Removed Oracle sample for .NET Framework.
  • Removed Oracle sample for .NET Framework (WebForms).


March 1, 2023


  • The size of POST requests to Designer API has been reduced.


  • Updated log4net, sharpcompress, Microsoft.Data.SqlClient, System.Text.Encodings.Web dependencies in the Framework examples.


  • Updated SSH.NET, SharpZipLib dependencies in FilesPlugin.


  • Removed SharpZipLib dependency.


February 21, 2023

There are no changes to the .NET libraries. In this version, only Workflow Designer packages are updated.


  • The style-loader package has been moved from dependencies to dev dependencies.
  • Updated some NPM packages in the Workflow Designer examples.
  • @optimajet/workflow-designer-angular package updated to Angular 15. This is breaking changes for this package.
  • Added an option to get a Vue instance, see our documentation for details.


February 13, 2023



  • Improved text display for RTL languages.
  • Fixed the location of the activity when creating in Firefox.
  • Changing the language no longer resets the schema state.


December 5, 2022


  • Added sort parameter for LoadGlobalParametersWithNamesAsync, LoadGlobalParametersAsync and LoadGlobalParametersWithPagingAsync methods of the IPersistenceProvider.
  • Sorting of global parameters is implemented by all persistence providers.


  • Fixed a bug with type mutations of default process parameters (fields of static instances of the ParameterDefinition class in DefaultDefinitions are made immutable).


  • Improved usability of zooming/scrolling.
  • Fixed a bug in workflow-designer-angular that caused apiurl not to change on the fly.


November 9, 2022


  • Updated vulnerable dependencies.


  • Fixed a bug in Angular & React npm packages where lifecycle events caused designer schemacode to be cleaned up.


November 7, 2022


  • Fixed a bug where subprocess logging would throw an exception.


  • Fixed a bug where the canvas scrolls even when any window was open.
  • Fixed a bug where clear executing would change the designer schemecode.


October 24, 2022


  • Improving the UX of scheme moving and scaling. Now you can move the scheme: up and down with the mouse wheel, left and right with the Shift + wheel, scale with Ctrl + wheel.
  • Fixed a bug with saving custom activity parameters without a template.
  • Fixed undo button bug.
  • Minor optimization.


  • The LoadGlobalParametersWithPagingAsync method has been added to the IPersistenceProvider interface. That allows you to request global parameters with paging and searching by name.


October 12, 2022


  • Fixed calling custom activity onUpdate with incorrect argument value.


  • Updated GitHub readme.


October 7, 2022


  • Added an option cacheLoadedFiles — caches downloaded files (e.g. templates), enabled by default.


  • Added a guide where we will explain how to integrate Workflow Engine with React.

And other minor improvements and fixes.


October 5, 2022


  • Added an optional button to save the schema to the server - docs. Save button
  • Updated and improved documentation on creating custom activity.

And other minor improvements and fixes.


September 22, 2022

  • Fixed Clone method in the ProcessDefinition.
  • Small bug fix in the designer.


September 16, 2022


  • The BPMN upload and download menu is now hidden by default (showBpmnMenu flag in designerConfig).

And other minor improvements and fixes.


August 29, 2022

Breaking changes

  • The .NET Framework 4.6.2 is now the minimum supported version.
  • Unified nuget packages for .NET Framework and .NET Core with the netstandard2.0 target.
  • Updated providers. Now there is less static, and this is a precursor of an even greater update of providers.
  • For .NET Framework users only: OptimaJet.Workflow.DbPersistence.dll renamed to OptimaJet.Workflow.MSSQL.dll.


  • Added the ability to export the process scheme to an image.
  • Added support for custom control for the action parameter.
  • Added comment for command and commands parameter.
  • Added ‘comment’ type for localization.
  • Added ability to add a custom language.
  • Fixed initialization of default values for activity.
  • Exceptions are no longer logged when logging is disabled.


  • Added the ability to set a global timeout for commands.


  • .NET Core samples updated to .NET 6.
  • Synchronous APIs have been replaced with asynchronous ones.

Also updated dependencies and other improvements and fixes.


July 6, 2022

Persistence Providers

  • The transaction is now disposed when the schema is deleted.


June 24, 2022


  • Fixed a graph loaded with an empty schema.


  • Updated Newtonsoft.Json library.


June 22, 2022


  • Expanded localization opportunities. See the Localization article.


  • Added the Localizer property for instances of WorkflowRuntime, ProcessInstance, ProcessDefinition.
  • Added the ILocalizationProvider interface for predefined localization.

And other improvements and fixes.

Breaking changes

The LocalizeDefinition class is now renamed to Translation.


May 31, 2022


  • Updated Slack API library.


  • Fixed scheme caching.


May 23, 2022


  • Fixed the logic of restrictions, their concatenation and checks.


  • Fixed BPMN upload in browser console.
  • Fixed scheme naming when downloading.


May 13, 2022


  • Fixed filename changing when downloading scheme.


April 29, 2022


  • Bug fix and minor improvements.


April 25, 2022


  • Added a predefined actor provider in the Basic plugin, which allows you to thread-safe control the list of actors.


April 19, 2022

Breaking changes

If you use the FileUncompress activity, then you need to resave the process schemas that use these activities in the updated designer.


  • Fixed spelling errors.


  • Fixed spelling errors.
  • Updated libraries Microsoft.CodeAnalysis.CSharp and Microsoft.CodeAnalysis.CSharp.Scripting to 4.1.0 version.


April 11, 2022


  • Fixed an error loading external templates when using npm packages.


  • Added CC, BCC, ReplyTo fields to the SendEmail activity.


April 4, 2022


  • Fixed errors in displaying process logs.


April 1, 2022


  • Fixed errors in displaying process logs.


  • Added an index for the ProcessId column in the WorkflowProcessTimer table for MSSQL, MySQL, Oracle databases.

Update instruction

The following additional actions must be taken to upgrade to Workflow Engine 5.2.4 from Workflow Engine 5.2:

  • Run the SQL script update_5_2_to_5_2_4.sql for all relative databases:
  • Update all files related to the Designer. They are available here.
  • Update NuGet packages or DLLs.


March 2, 2022


  • The Name parameter will now be determined after the UploadAsync and UploadBPMNAsync methods are executed.
  • Fixed an issue where keyboard shortcuts did not work in Firefox.
  • Fixed issue with endless loading of logs. Fixed problem with loading fonts from Google CDN.


  • Pre-Execution mode now has an infinite loop protection mechanism. Use WorkflowRuntimeSettings.MaxPreExecutionTransitions to define the maximum number of transitions during pre-execution.
  • Added an ClearApprovers action in the Basic plugin to reset the parallel approval. See also Basic plugin API.
  • Added the ability to use LINQ in Expressions.
  • Fixed an issue with parallel approval in the Basic plugin ((ArgumentNullException) Value cannot be null. (Parameter 'key')).


December 29, 2021


  • Removed some global styles.


  • Fixed rule exclusion.


December 8, 2021


  • Added the ability to change the transition classifier in the Decision and Decision Table elements in expert mode.


October 27, 2021


  • Now the Designer is published to npm, there are three packages: for any project, Angular and React.

  • Process history displayed in the designer now has server paging.

  • Upload and download of BPMN files can be customized using the following delegates:

    WorkflowInit.Runtime.BPMNApi.CustomDownload += (definition, scheme) => { };
    WorkflowInit.Runtime.BPMNApi.CustomUpload += (definition, scheme) => { };
  • Added a possibility to write user comments to activities and transitions.

  • The date picker are used in the DateAndTime, Date, Time timer types.


  • The Basic Plugin provides actions/activities to set states and execute commands in another process.

  • The SetParameter action/activity from the Basic Plugin now accepts expressions as the parameter value, i.e. you can set any parameter with expression based on other parameters, for example:

    @Amount * 2 + 100
  • A new Assignment Plugin to provide human tasks features was added. Read more about in the documentation Plugins/AssignmentPlugin.

  • The CreateProcess action/activity allows the passing parameters to the created process. You can use expressions in the process values.

  • The CheckApproversExist condition added to the Basic Plugin allows making conditional branch if nobody can approve the document.


  • Added a stored procedure to clear unused schemes from WorkflowProcessSchemeTable, you can execute it using the following code:

    await WorkflowInit.Runtime.PersistenceProvider.DropUnusedWorkflowProcessSchemeAsync();
  • Added overloaded methods GetAvailableCommandsAsync and GetAvailableStateToSetAsync that take a process instance as a parameter.

  • Added a method to search global parameters by their type name.

  • If the process fails the exception message and stack trace will be saved to LastError and LastErrorStackTrace process parameters.

  • Now it is possible to use non-Latin characters in parameter names, which are then used in expressions.

  • Added two methods that's can be useful in offline mode:

    // returns all available transitions with commands for the user, these commands can be executed while the device is offline
    await WorkflowInit.Runtime.OfflineApi.GetApprovalMapAsync(...);
    // executes a series of commands when the device becomes online
    await WorkflowInit.Runtime.OfflineApi.ExecuteSomeCommandsAsync(...);
  • You can have more precise control of disabling the process state persisting. You can separately disable persisting process state, persisting process parameters, and persisting transition history.

  • PreExecuteAsync method returns the List of activities that's will be executed.

  • The Date, DateTime, and Time parameter types are available for action/condition/rule parameters edit forms. They are displayed as date-time pickers.

  • The new Timer type - Expression is implemented. You can write expressions here that's will be interpreted the following way:

    • if the expression returns DateTime the timer will be set to this DateTime.
    • if the expression returns an integer value the timer will act as an interval timer where the returned value is interpreted as the interval in milliseconds.

    For example, you can write the following expressions (let's imagine that you have a Document process parameter with CreatedDate property):

  • Added a method to get actors with commands:

    await WorkflowInit.Runtime.ActorsApi.GetActorsWithCommandsAsync(...);

Breaking changes

Please, pay attention to these breaking changes before updating.

  • The Workflow Designer isn't provided as the NuGet package anymore.

  • If you are using DateTime parameter types in parameter edit forms, please check that you are parsing them the standard way (DateTime.Parse for example), because now they are selected from date picker, and it saves them to string in more ISO style:

    // no timezone, but it was valid in previous version
    Before: 2021-11-05 18:07
    // selected in local time, saved in UTC
    After: 2021-11-05T15:07:00.000Z
  • If you are using SetParameter action/activity from the Basic Plugin pay attention that:

    • Before the parameter value was always interpreted as a string
    • Now the parameter value is the compilable expression

    You have two options how to preserve old behavior:

    • Quote the parameter value:

      Before: Some Value
      After: "Some Value"
    • Switch on old behavior when initializing the Basic Plugin:

      basicPlugin.Setting_DontCompileExpressions = true;

Update instruction

The following additional actions must be taken to upgrade to Workflow Engine 5.2:

  • Run the SQL script update_5_1_to_5_2 for all relative databases and MongoDB.
  • Update all files related to the Designer. They are available here.
  • Update NuGet packages or DLLs.


March 31, 2021


  • Improved designer’s usability.
  • Added creation of commands from the transition’s edit form.
  • It is possible to customize displayed activities and transitions, their templates are located in the templates/elements folder and are .svg files that can be changed.
  • It became possible to choose a color for displaying activity and transition.
  • For custom activities added on the server, it is now possible to specify the template for the edit form and .svg to be displayed on graph.
  • A new type of activity Decision has been added to the elements panel – it is used for convenience and to improve the visual perception of processes with conditional branches. It allows you to make a branch with one condition.
  • A new type of activity Decision Table has been added to the elements panel – it is used for convenience and to improve the visual perception of processes with conditional branches. It allows you to make a branch with any number of conditions.
  • The design of editing usings in Code Actions has been changed.


  • Extended the functionality of the Approval Plugin, now it fully allows you to implement the functionality of Inbox, Outbox, and the history of document changes. All examples implement this functionality using the Approval Plugin.
  • Methods for manipulating Inbox, Outbox and the history of document changes are added to Persistence Providers. The history of document changes, Inbox and Outbox are only filled when Approved Plugin is connected.
  • The ability to register Actors predefined on the server is added in the Basic Plugin. The basicPlugin.WithActors method and two delegates: basicPlugin.CheckPredefinedActorAsync and basicPlugin.GetPredefinedIdentitiesAsync are used for this.
  • You can now specify a delegate to update the status(state) of the document - basicPlugin.UpdateDocumentStateAsync in the Basic Plugin.
  • A DeleteSubprocesess action is added to the Basic Plugin, this action deletes all subprocesses.
  • Added the ability to customize HTTP requests headers in the Basic Plugin’s CheckHTTPRequest and HTTPRequest methods.
  • The ability to specify a username and password for all the methods that make HTTP requests has been added to the Basic Plugin.
  • The ability to download files by HTTP has been added to the File Plugin.
  • It is now possible to specify the ID of the created process in the CreateProcess method in the Basic Plugin.


  • You can now set common usings for all Code Actions of the scheme, at the same time you can configure usings individually for each Code Action. This makes usings managing easier.
  • Added process log. The sequence of actions that occurs during the execution of the process is now added to a process log. The log can be enabled for all processes created for a specific scheme or for a specific process. Attention: The Workflow Engine package includes a logger that stores the log in the memory. This is enough for debugging processes but if you want to make the log persistent, you have to implement the IProcessLogProvider and connect it to the Workflow Runtime by calling the runtime.WithProcessLogger(…) method.
  • GetProcessInstancesAsync(...) and GetSchemesAsync(...) methods that accept sorting and paging are added to the Persistence Provider. With their help you can access the list of schemes and processes.
  • The Activity in Expert mode in the Designer now has the ability to set the Execution Timeout, meaning it limits the execution time of all Actions of this Activity. Attention: This timeout with only work for asynchronous Actions that process the Cancellation Token passed to them. The timeout value is the same as the interval timer value. Possible reactions to timeout: Set Activity, Set State, Retry.
  • The Activity in Expert mode in the Designer now has the ability to set Idle Timeout, meaning it limits the time a process can be in this Activity without doing anything (i.e. Idled or Finalized status of the process). The timeout value is the same as the interval timer value. Possible reactions to timeout: Set Activity, Set State.
  • The Activity in Expert mode in the Designer now has the ability to set Error handling by listing the names of the exceptions that need to be handled. Possible reactions to the exception: Set Activity, Set State, Retry, Ignore.
  • The Activity in Expert mode in the Designer now has the ability to disable saving process state. This setting is called Disable persist.
  • Process Instance is passed to the HasExternalParameter, IsGetExternalParameterAsync, IsSetExternalParameterAsync of IWorkflowExternalParametersProvider methods.
  • Two time-stamps were added to Process Instance: CreationDate – date and time of process creation and LastTransitionDate – date and time of the last change of the process state.
  • StartTransitionTime – date and time of the beginning of the transition and TransitionDuration – the duration of the transition in milliseconds - were added to the Process Transition History.
  • An additional parameter NamesSearchType.All or NamesSearchType.NotExcluded is passed in the IWorkflowActionProvider.GetActions, IWorkflowActionProvider.GetConditions and IWorkflowRuleProvider.GetRules methods, this allows adding Actions, Conditions or Rules that are not seen the Designer but that are executed in the process.

Update instruction

The following additional actions must be taken to upgrade to Workflow Engine 5.1:

  • Warning. If using Redis, please, contact our support for update instructions.
  • Run the SQL script update_5_0_to_5_1 for all relative databases and MongoDB.
  • Update all files related to the Designer. They are available here. Be mindful, that the elements subfolder must be added to the templates folder.
  • If you are using Action or Rule Providers in the IWorkflowActionProvider.GetActions, IWorkflowActionProvider.GetConditions and IWorkflowRuleProvider.GetRules methods add the last NamesSearchType namesSearchType parameter. You don't need to change the code of these methods.
  • If you are using External Parameters Provider in the HasExternalParameter, IsGetExternalParameterAsync and IsSetExternalParameterAsync methods add the last ProcessInstance processInstance parameter. You don't need to change the code of these methods.


October 7, 2020


  • Designer windows have been reworked to behave as non-modal which allows:
    • to keep them open while working with a scheme.
    • to open multiple windows, change their size and behavior.
  • Customization of Designer windows is now simplified; each window is represented by a Vue.js template which can be now altered independently from the rest of the Designer.
  • Customization of Designer toolbars simplified.
  • A Designer library of typical schemes added which represent most frequently used blocks which can be dragged onto your schemas.
  • A library of custom activities added; these are single action activities whose settings are adjustable within the form.
  • Forms to edit properties of activities and transitions now have two viewing modes - Default and Expert. The Default mode represents only the essential and most used settings, while the Expert mode combines all the settings.


  • Sub-processes can now be launched in a separate thread to allow for physical parallelism at the scheme level.
  • Methods to copy parameters into a sub-process can now be carried out using the following options:
    • copy all parameters (default option, previously available)
    • not to copy parameters
    • only copy specified parameters
    • ignore specified parameters.
  • New feature to specify a method to transfer sub-process parameters on to its parent process when merging. The following options are available:
    • transfer only the parameters absent in the parent process (default option, previously available)
    • transfer all parameters
    • only copy indicated parameters
    • ignore indicated parameters.
  • New feature to clearly indicate whether a particular transition starts a sub-process or finalizes it; previously identified automatically, the transition can be now obviously set.
  • New feature to specify a sub-process name which can be represented as a simple string or a calculated expression; expressions can consume parameters (this is syntactically similar to conditional expressions). In this way, new sub-processes can be created simply by changing parameter values used when a sub-process name is generated. As an example, consider creating an invoice approval scheme where the invoice will contain several product items. It is now possible to design a scheme in which approval of the items will be represented by a sub-process. Furthermore, by combining loops (in the plugin) and sub-process naming calculations a sub-process for each product item can be created.
  • New feature to specify a sub-process id, or calculate it based on the parameters; herein, substitutions are used - not expressions.

Persistence Providers

  • All persistence providers are implemented as completely asynchronous. As a result, the Workflow Engine core operates in a completely asynchronous fashion suitable for scalability.
  • .NET Core provider for MsSql utilizes Microsoft.Data.SqlClient instead of System.Data.SqlClient.

Workflow Runtime

  • Method Resume is added to API Workflow Runtime. Contrary to the SetState method, it does not execute a current activity, or a set one, but rather attempts to continue execution of the process. This method can be used to go on with a process execution after a failure, or in the case of changes in external conditions.
  • Restorer Restore Decision Resume added.
  • New in the ProcessInstance class:
    • Indexer for getting and setting parameter values
    • Methods to manipulate root process parameters from within a sub-process.
    • For all standard events, now exist their asynchronous counterparts.


  • FTP and SFTP support added to the File Plugin. Attention. File Plugin is supplied as a separate Nuget package/dll
  • New plugin, Loops Plugin, added for simple implementation of the for and foreach.
  • Within the action BasicPlugin.HttpRequest you can specify the name of the parameter which is to hold the result.
  • Within the action BasicPlugin.SetParameter, and the BasicPlugin.CheckParameter condition, you can set and verify the root process' parameters.
  • Many new conditions added to BasicPlugin.CheckParameter and BasicPlugin.CheckHTTPRequest.
  • New plugins added for interaction with Slack, Telegram, Twilio, Nexmo are provided as Nuget packages (dlls).

Update instruction

The following additional actions must be taken to upgrade to Workflow Engine 5.0:

  • Warning. If using Redis, please, contact our support for update instructions.

  • Run the SQL script update_4_2_to_5_0 for all relative databases and MongoDB.

  • Update all files related to the Designer. They are available here.

  • Be mindful, that these files must be linked to the designer page:

    • workflowdesigner.min.css
    • workflowdesigner.min.js
    • jquery

    All the other javascript libraries previously required, do not need a separate attachment for they are now compiled inside workflowdesigner.min.js.

  • Pay attention to the new way of initializating a WorkflowDesigner object instance.

    wfdesigner = new WorkflowDesigner({
    name: 'simpledesigner',
    apiurl: '/Designer/API',
    renderTo: 'wfdesigner',
    templatefolder: '/templates/',
    graphwidth: graphwidth,
    graphheight: graphheight
    • Indicating the path to the images folder is no longer required and the folder can be deleted.
    • Yet, the path to the templates folder must be specified as it contains templates for all the forms and the library of schemes.
    • It is advised to reimplement WorkflowDesigner initializations, as is shown here.
  • If you are using .NET Framework you may need to use Request.Unvalidated[key] instead of context.Request.Form[key] in the DesignerController.cs.

  • Attention. Event handlers OnSchemaWasChanged and OnSchemaWasChangedAsync are now initialized inside a locked process. That is, prior to releasing the Running status. The code, as described in the documentation will continue to work as expected without need to change it. Yet, if SetActivityWithoutExecution[Async] or SetActivityWithExecution[Async] are called in these handlers, it should be done using this flag doNotSetRunningStatus = true. In turn, if you utilized methods ExecuteCommand, SetState and similar, be aware that there methods which lock the process. Therefore, is might be best to use methods: SetActivityWithoutExecution[Async] or SetActivityWithExecution[Async]. If you have implemented a complicated logic for updating schemes which leads to a failed attempt at updating you the Workflow Engine version because of this change, reach us at, and we'll help you.


May 18, 2020

  • Support for the timers in multi-server mode has been added. You can configure WorkflowRuntime to work in a single or multi-server environment. This affects the timers and the recovering from failure. You can configure the runtime with the following code:

    _runtime = new WorkflowRuntime()
    .AsSingleServer() // .AsMultiServer()

    WARNING. AsMultiServer() - works for Ultimate licenses only.

  • If an abnormal server shutdown has occurred, then part of the processes may remain frozen in the Running status. This status will be changed by the automatic recovery procedure; one of the two statuses - either Error or Terminated - will be set. You can also change the recovery procedure using Process Restorer. For example, as follows:

    public class ProcessRestorer : IProcessRestorer
    runtime.WithProcessRestorer(new ProcessRestorer())

    Please, note that Process Restorer is only used in a case of server shutdown. For the workflow errors, use the OnWorkflowError event handler.

  • The runtime.Shutdown() and runtime.ShutdownAsync() methods has been added. These methods provide the correct shutdown of the WorkflowRuntime. Using this method is very important for a multi-server environment.

  • The approach to the workflow execution has been changed. Now, the process is executed using a run loop. Therefore, you can create an endless workflow. One iteration of the loop is equivalent to one Activity. By default, the maximum number of iterations is limited by Int64.MaxValue. However, you can change it as follows:

    _runtime.WithRuntimeSettings(new WorkflowRuntimeSettings()
    MaxNumberOfPerformedActivities = -1 // Infinite loop allowed
  • Now, you can safely change the workflow state from the workflow itself during its operation. Use the following code:

  • If the complex object is stored in the process parameters, you can receive and set its properties on the fly, using partial parameters:

  • A new type of Expressions has been added. This is a simple expression that returns true or false. You can use them instead of Conditions. Here, you can use the process parameters values, as well as string formatting of these parameters. The syntax of these expressions is as follows:

    @ObjectParameter.BooleanProperty and @IntParameter <> 1

    Here the 'ObjectParameter.BooleanProperty' and 'IntParameter' are Process parameters.

  • The parameters values can be substituted into the values of the Actions, Conditions, or Rules. The syntax is similar to the expressions:

    JsonObject = "@ObjectParameter:json",
    Int = "@IntParameter:json",
    IntString = "@IntParameter",
    Guid = "@GuidParameter:json",
    GuidString = "@(GuidParameter:N)",
    DateTime = "@(DateTimeParameter:json)",
    DateTimeString = "Today is @(DateTimeParameter:dd-MM-yyyy HH:mm:ss)",
  • You can connect the external parameter provider - IWorkflowExternalParametersProvider - to WorkflowRuntime. This allows you to access external data (for example, the document record which the process is linked to) as usual process parameters. It can be used in Expressions.

  • A plugin to work with files has been added - File Plugin.

  • A plugin to work with Inbox/Outbox has been added - Approval Plugin.

  • HTTPRequest and CheckHTTPRequest methods added by Basic Plugin can now send POST.

  • Methods to simplify work with parallel processes have been added to Basic Plugin.

  • In the Parameter edit forms you can use the Multiselect Dropdown.

The following additional actions must be taken to upgrade to Workflow Engine 4.2:

  • Warning. RavenDB provider is no longer supported.

  • Warning. If using Redis, please, contact our support for update instructions.

  • Warning. If you are using MongoDB. The multi-server feature will work only with MongoDB version > 4.0

  • Run the SQL script update_4_1_to_4_2 for all relative databases and MongoDB.

  • Update all files related to the Designer. They are available here.

  • Update packages or dll to version 4.2. **If you connect the Workflow Engine with DLLs you must reference all DLLs from this archive in your solution.

  • Remove runtime.WithBus(...) call from your WorkflowRuntime configuration.

  • At the point, where you configure WorkflowRuntime remove the .WithTimerManager (...) call. And add a call of .AsSingleServer() or .AsMultiServer(), depending on the mode you want to run the WorkflowRuntime. WARNING. AsMultiServer() - works for Ultimate licenses only.

  • The signature of the UsersInRoleAsync delegate for Basic Plugin has changed. The way, it was:

    public delegate Task<IEnumerable<string>> UsersInRoleAsyncDelegate(string roleName, Guid? processId = null);

    The way, it is now:

     public delegate Task<IEnumerable<string>> UsersInRoleAsyncDelegate(string roleName, ProcessInstance processInstance);
  • If you are using .Net Framework for your web application most likely you must add the following lines in your web.config.

    <compilation debug="true" targetFramework="4.5">
    <add assembly="System.Runtime, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />


January 9, 2020

  • Support for multi-tenant applications.

    • TenantId has been added to processes. When creating a process, one can specify TenantId and use its value when working with the process. TenantId is stored in the WorkflowProcessInstance table in the TenantId column. Passing TenantId to a process:

      var createInstanceParams = new CreateInstanceParams(schemeCode, processId) { TenantId = "tenantId" };

      After creating a process with TenantId indicated, the access to it inside Actions, Conditions and Rules can be arranged as follows.

      string tenantId = processInstance.TenantId;
    • For schemes one can specify tags, and then, search for schemes where these tags are indicated. Tags are set in the scheme designer by clicking on the Process Info button. Tags are stored in the WorkflowScheme table in the Tags column. A list of codes for the schemes where the corresponding tags are indicated can be received using the following code:

      List<string> schemeCodes =  workflowRuntime.Builder.SearchSchemesByTags(new List<string> {"Tag1", "Tag2"});

      The search is performed using an OR expression.

  • Plugin System and the Basic Plugin. The plugin for WorkflowEngine.NET is a class that is necessary to implement the IWorkflowPlugin interface, and optional to implement the IWorkflowActionProvider, IWorkflowRuleProvider, IDesignerParameterFormatProvider, IDesignerAutocompleteProvider interfaces (in any combination). In fact, the plugin is a class that adds functionality to be used when creating process schemes. The plugin connects to WorkflowEngine.NET when configuring WorkflowRuntime.

    WorkflowRuntime workflowRuntime = workflowRuntime.WithPlugin(new BasicPlugin());

    Simultaneously, any number of plugins can be connected to WorkflowEngine.NET. The Basic Plugin OptimaJet.Workflow.Core.Plugins.BasicPlugin has been added to the WorkflowEngine.NET package; it implements the following basic functions:

    • Actions:
      • SendEmail - sending email.
      • CreateProcess - creating a process from a process.
      • HTTPRequest - sending a request to a third-party web service.
      • SetParameter - setting a process parameter.
    • Conditions:
      • IsProcessFinalized - checking the finalization of the current process or a process with the Id specified.
      • CheckAllSubprocessesCompleted - checking the finalization (completion) of all the subprocesses.
      • CheckParameter - checking if the parameter is consistent to the given value (so far, only strings are supported).
      • IsAprrovedByUsers - checking if the specified process was processed by all of the listed users.
      • IsAprrovedByRoles - checking if the specified process was processed by all of the listed roles.
      • CheckHTTPRequest - conditional transition based on the result of a request to a third-party web service.
    • Authorization Rules (Security):
      • CheckRole - checking access to the command for a specific role. Warning: to perform operations related to the roles checking, BasicPlugin must have the delegate handler basicPlugin.UsersInRoleAsync installed.
  • Now, implicit (that is, not explicitly specified in the scheme) parameters passed when creating a process, executing a command, or setting a new state to a process can be persistent.

    • When creating a process, use the following code:

      var createInstanceParams = new CreateInstanceParams(schemeCode, processId)
      .AddPersistentParameter("Parameter1Name", 100)
      .AddPersistentParameter("ParameterName2", parameterValue);
    • When passing parameters with a command, use the following code:

      WorkflowCommand command = ...
      command.SetParameter("ParameterName", parameterValue, persist: true);
      workflowRuntime.ExecuteCommand(command, ... );
    • When passing a parameter with a command, use the following code:

      var setStateParams = new SetStateParams(processId,"StateName")
      .AddPersistentParameter("Parameter1Name", 100)
      .AddPersistentParameter("ParameterName2", parameterValue);
  • Support for dynamic parameters has been added. To perform the task, the DynamicParameter class, which can be cast into dynamic, has been developed. For example:

    Creating a parameter:

    var dynamicParameter = new
    Name = "Dynamic",
    ObjectValue = new
    Name = "Object",
    Value = 100
    ListValue = new List<object> {
    new {Id = 1, Name = "ObjectInList1"},
    new {Id = 2, Name = "ObjectInList2"}
    processInstance.SetParameter("Dynamic", dynamicParameter, ParameterPurpose.Persistence);

    Getting a parameter:

    var dynamicParameter = processInstance.GetParameter<DynamicParameter>("Dynamic") as dynamic;
    string name = dynamicParameter.Name;
    string objectValueName = dynamicParameter.ObjectValue.Name;
    string firstItemName = (dynamicParameter.ListValue as List<dynamic>).First().Name;
  • The following aggregating providers are available: AggregatingActionProvider, AggregatingRuleProvider, AggregatingDesignerAutocompleteProvider, AggregatingDesignerParameterFormatProvider. An aggregating provider is a provider to which other providers can be added.

  • IWorkflowRuleProvider - supports asynchronous authorization (security) rules.

  • The scheme code is passed to all methods of all providers. Here are these methods

    • IWorkflowActionProvider.GetActions
    • IWorkflowActionProvider.GetConditions
    • IWorkflowActionProvider.IsActionAsync
    • IWorkflowActionProvider.IsConditionAsync
    • IWorkflowRuleProvider.GetRules
    • IWorkflowRuleProvider.IsCheckAsync
    • IWorkflowRuleProvider.IsGetIdentitiesAsync
    • IDesignerParameterFormatProvider.GetFormat
    • IDesignerAutocompleteProvider.GetAutocompleteSuggestions

    string schemeCode has been added as the last parameter to all these methods.

  • A unified and correct error output when accessing the Designer API has been added.

  • Intellisense has been added in the Code Actions (code in schemes) editor.

  • A new type TextArea has been added to the forms where parameter (for Actions, Conditions or rules) values are edited.

  • In any of the persistence providers, one can optionally turn off the history of transitions and set the history of subprocesses to be written in the history of the main process. For example:

    var provider = new MSSQLProvider(connectionString, writeToHistory:false);
    var provider = new MSSQLProvider(connectionString, writeSubProcessToRoot:true);

Update guide to the Workflow Engine 4.1

The following additional actions must be taken to upgrade to Workflow Engine 4.1:

  • Run the following SQL script for all relative databases.

  • Update all files related to the Designer. They are available here.

  • Update packages or dll to version 4.1.

  • If the IWorkflowActionProvider interface is implemented in your project, the last parameterstring schemeCode shall be added to the following methods:

    • IWorkflowActionProvider.GetActions
    • IWorkflowActionProvider.GetConditions
    • IWorkflowActionProvider.IsActionAsync
    • IWorkflowActionProvider.IsConditionAsync
  • If the IWorkflowRuleProvider interface is implemented in your project, the following methods shall be added to your provider:

    public Task<bool> CheckAsync(ProcessInstance processInstance, WorkflowRuntime runtime, string identityId, string ruleName, string parameter, CancellationToken token)
    throw new NotImplementedException();

    public Task<IEnumerable<string>> GetIdentitiesAsync(ProcessInstance processInstance, WorkflowRuntime runtime, string ruleName, string parameter, CancellationToken token)
    throw new NotImplementedException();

    public bool IsCheckAsync(string ruleName, string schemeCode)
    return false;

    public bool IsGetIdentitiesAsync(string ruleName, string schemeCode)
    return false;

    The last parameter string schemeCode shall be also added to the following method:

    • IWorkflowRuleProvider.GetRules
  • If the IDesignerParameterFormatProvider interface is implemented in your project, the last parameter string schemeCode shall be added to the following method:

    • IDesignerParameterFormatProvider.GetFormat
  • If the IDesignerAutocompleteProvider interface is implemented in your project, the last parameter string schemeCode shall be added to the following method:

    • IDesignerAutocompleteProvider.GetAutocompleteSuggestions
  • IMPORTANT! Incorrect behavior was fixed when the subprocess was merged in the parent process via the set state of the parent process mechanism. Previously, the parent process parameters were OVERWRITTEN. Now, the parent process parameters won't be changed. Only new parameters from the subprocess will be written to the parent process automatically. The same way the merge via calculating conditions always works. If you consciously exploited this behavior, then the best way to get parameters from the subprocess is to use a property processInstance.MergedSubprocessParameters when merge occurs.

  • IMPORTANT! If in your project the Action Provider has changed (after the first initialization) using the method workflowRuntime.WithActionProvider(...) replace this code with the following call workflowRuntime.ClearActionProvider().WithActionProvider(...)

  • IMPORTANT! If in your project the Rule Provider has changed (after the first initialization) using the method workflowRuntime.WithRuleProvider(...) replace this code with the following call workflowRuntime.ClearRuleProvider().WithRuleProvider(...)

  • IMPORTANT! If in your project the Designer Autocomplete Provider has changed (after the first initialization) using the method workflowRuntime.WithDesignerAutocompleteProvider(...) replace this code with the following call workflowRuntime.ClearDesignerAutocompleteProvider().WithDesignerAutocompleteProvider(...)

  • IMPORTANT! If in your project the Designer Parameter Format Provider has changed (after the first initialization) using the method workflowRuntime.WithDesignerParameterFormatProvider(...) replace this code with the following call workflowRuntime.ClearDesignerParameterFormatProvider().WithDesignerParameterFormatProvider(...)

  • It is not necessary but suggested to change the Designer Controller the following way

    public ActionResult API()
    var res = WorkflowInit.Runtime.DesignerAPI(pars, out bool hasError, filestream, true);
    var operation = pars["operation"].ToLower();

    if (operation == "downloadscheme" && !hasError)
    return File(Encoding.UTF8.GetBytes(res), "text/xml", "scheme.xml");
    else if (operation == "downloadschemebpmn" && !hasError)
    return File(UTF8Encoding.UTF8.GetBytes(res), "text/xml", "scheme.bpmn");

    return Content(res);

    See complete controller code

  • It is not necessary but suggested to pass the scheme code when calling wfdesigner.create() method on the Designer page.


    See complete view code


April 25, 2019

  • Designer usability improvement. Transition info will now be displayed in a fuller, more comprehensive form. You can now switch between full screen and normal edit window display modes. Toolbars design has been changed.
  • you can customize Activity and Transition rendering in the Designer.
  • you can customize Designer windows.
  • Designer performance has been optimized.
  • Scheme inlining. Now you can check a scheme as a scheme that can be inlined and embed it into another scheme. Thus, you can re-use typical parts of your processes many times, without copying them between schemes. Multi-layered inlining is supported.
  • Process Info window has been added into the specific process view mode. It allows you to view this process parameters, transition history, launched timers. Here full information on subprocesses is also displayed.
  • You can specify annotations for Activity and Transition. Annotations are a dictionary (key - value) which you can set in the Designer individually for each Activity ot Transition. You can read annotation value in the code, using the following methods: activityDefinition.GetAnnotation<T>(name), transitionDefinition.GetAnnotation<T>(name), processInstance.ProcessScheme.GetActivityAnnotation<T>(activityName, name), processInstance.ProcessScheme.GetTransitionAnnotation<T>(transitionName, name)
  • For the string parameter, which is transferred into Actions, Conditions and Rules, you can specify the structure which will define the form in which this parameter will be displayed in edit mode in the Designer. Form field contents can be specified in the Designer in the CodeActions section. Or you can create a class implementing IDesignerParameterFormatProvider interface on the server and configure your WorkflowRuntime in the following way: workflowRuntime.WithDesignerParameterFormatProvider(new YourDesignerParameterFormatProvider()). Thus, you can specify the appearance of the string parameter which is transferred into Action, Condition or Rule.
  • In the event handler workflowRuntime.OnWorkflowError you can now cancel exception throwing, using event arguments args.SuppressThrow = true;. Also, you can specify the Activity, which will be set after error processing. For example, it can be initial activity: args.ActivityToSet = args.ProcessInstance.ProcessScheme.InitialActivity;
  • For simple execution of complex business cases in WorkflowRuntime use two of the following methods: workflowRuntime.GetAvailableCommandsWithConditionCheck(...) - get the list of available commands with additional conditions check, and workflowRuntime.ExecuteCommandWithRestrictionCheck(...) - execution of the command with additional restrictions check.
  • Correct merging of the subprocess and parent process has been added, when a subprocess is merged with its parent process immediately after launch. In other words, if a subprocess contains only Auto triggered transitions. Now merge will be correct, and the subprocess will wait till the parent process is unlocked.
  • Process execution can be cancelled using CancellationToken. Such cancellation will be activated automatically if you configure your WorkflowRuntime in the following way: workflowRuntime.SetCancellationTokenHandling(CancellationTokenHandling.Throw).

The following additional actions must be taken to upgrade to Workflow Engine 4.0:

  • Don't forget to update packages or dlls, and the Designer javascript, css and all designer related images.
  • Run the SQL script update_4_0.sql for all relative databases. You will find this script in your provider's archive.
  • If you have used process status change (for example args.ProcessStatus = ProcessStatus.Idled;) to cancel exception release after the event has been processed workflowRuntime.OnWorkflowError, you will need to use the following code args.SuppressThrow = true;. Status change hack won't work, custom status will be installed, but the exception will still be thrown.


January 16, 2019

  • Moving the canvas (in the Move mode) with arrows was added to the designer.
  • Explicit passing of CultureInfo was added to methods GetInitialCommands, GetInitialState, GetCurrentState and GetAvailableCommands of the WorkflowRuntime class
  • Full samples (Vacation request approval) for all supported databases for ASP.NET Core and ASP.NET MVC. Full samples for MSSQL, Postgres and Oracle database for Web Forms.


November 5, 2018

  • Added automatic size increase for background in designer.
  • Added designer localization files for German, French, Spanish, Italian, Portuguese, Turkish, and Russian languages.
  • .NET Core NuGet packages come with .NET Standard 1.6 and .NET Standard 2.0 libraries. This allows you to use these packages with any .NET Core version, including 2.1.
  • The OptimaJet.Workflow.Core.Logging.ILogger interface was added; it can be initializes with your own logger in the WorkflowRuntime object. It is used to integrate with the Workflow Server logging system, but you can use it to integrate with your own system. Bear in mind that the logger in the WorkflowRuntime object is not initialized by anything by default.


September 12, 2018

  • MongoDB provider for Workflow Engine .NET Core was added.
  • MongoDB driver was updated to version 2.7. You can now connect to CosmosDB through a MongoDB connection.
  • The following hotkeys were added to the Workflow Designer:
    • Ctrl + A - Select all
    • Ctrl + C - Copy selected items
    • Ctrl + E - New Activity
    • Ctrl + I - Extended info
    • Ctrl + Y - Redo
    • Ctrl + Z - Undo
    • Arrows - Move selected items
    • Delete - Delete
    • Alt + Enter - Full-screen mode
    • Ctrl + M - Move mode

The following additional actions must be taken to upgrade to Workflow Engine 3.3 if you are using MongoDB:

  • Only for MongoDB users: it is necessary to apply the update_3_2_to_3_3.js script to your database.


August 17, 2018

  • Added providers for MySQL and Oracle, running under .NET Core
  • Added class AggregatingRuleProvider, designed to combine several IWorkflowRuleProvider into one IWorkflowRuleProvider.
  • Added class AggregatingActionProvider, designed to combine several IWorkflowActionProvider into one IWorkflowActionProvider.


June 6, 2018

  • Workflow Engine's relational database storage system has been optimized. Additional indices have been built; obsolete indices have been removed; the size of some columns has been changed. Generally, these changes should result in the improvement of Workflow Engine's performance, especially for Microsoft SQL Server. All these changes have already been included into installation scripts; use the update_3_1.sql script to update the existing databases.
  • BulkCreateInstance now works for Microsoft SQL Server and .NET Core (version >= 2).


The update_3_1.sql script contains a change of index and size of certain columns. Be particularly careful when applying it to the production database.


  • The interface of Workflow Designer has been revamped to improve usability
    • The look and feel of the scheme has been changed
    • The library that renders popup windows and controls has been changed from jQuery UI to Semantic-UI. jQuery UI has been removed from the project completely. Autocomplete for lists has been implemented with jQuery-autoComplete
    • The Konva.js version has been updated to 2.0.2
    • The 'Extended Info' mode has been added to provide additional information needed when creating a workflow scheme
    • Undo and redo have been added
    • Current activity of subprocesses is now highlighted
    • Global CodeActions have been simplified
    • Scheme legend has been added
  • Builds for .NET Core 2.0 and .NET Standard 2.0 have been included to .NET Core packages
  • The order of search for Action, Condition and Rule in Code Actions and IWorkflowActionProvider(IWorkflowRuleProvider) has been changed. Earlier on, the order was as follows (highest to the lowest priority): Global CodeAction, CodeAction in the scheme, IWorkflowActionProvider(IWorkflowRuleProvider). Now this order is the following by default: CodeAction in the scheme, Global CodeAction, IWorkflowActionProvider(IWorkflowRuleProvider). Thus, CodeAction in the scheme has the highest priority. Search priority can be set with the runtime.SetExecutionSearchOrder(ExecutionSearchOrder order) setting.
  • Parameter type names used to be stored as an assembly qualified name (by specifying the version of the build and the public key token), which resulted in troubles when migrating schemes from the .NET Framework environment to the .NET Core environment. Now a simplified type name - the one that is displayed in Designer - is stored in the scheme. Old schemes are loaded without changes; type names will be replaced after the first save of the scheme in the Designer.
  • Errors that occur when there's a '-' in CodeAction names have been fixed.

The following additional actions must be taken to upgrade to Workflow Engine 3.0:

  • It is not necessary to update to the new version of the Designer; however, we strongly advise it. The old version of the Designer shall work with the new versions of the Workflow Engine at least within the next half a year. If you are updating to the new version of the Designer, introduce the following changes to the pages where Designer is displayed.
    • Delete links to jquery-ui.min.css and jquery-ui.js
          <link href="/Content/themes/base/jquery-ui.min.css" rel="stylesheet" type="text/css"/>
    <script src="/Scripts/jquery-ui.js" type="text/javascript"/>
    • Add links to semantic.min.css, semantic.min.js,
          <link href="/Content/semantic.min.css" rel="stylesheet" type="text/css"/>
    <script src="/Scripts/semantic.min.js" type="text/javascript"/>
    <script src="/Scripts/" type="text/javascript"/>
  • If the new order of search for Action, Condition and Rule does not suit you, change it with the following setting:
runtime = runtime.SetExecutionSearchOrder(ExecutionSearchOrder.GlobalLocalProvider);

Then, everything shall work the same way it did in the previous versions.

  • Workflow Engine's reaction to the scenario where it could not find an Action, Condition or Rule in CodeActions or IWorkflowActionProvider(IWorkflowRuleProvider) has been changed. Earlier on, Workflow Engine ignored this scenario which made it difficult to debug schemes. Now, the NotImplementedException exception is thrown, specifying the name of the object which was not found. If this behavior does not suit you, use the following setting:
runtime = runtime.SetIgnoreMissingExecutionItems(true);


October 1, 2018

  • A 'Refresh' button and its functionality have been added to Designer
  • A 'Full Screen' button and its functionality have been added to Designer
  • BulkCreateInstance and TimerManager performance has been enhanced
  • Scroll-based scaling has been added to Designer


  • Now it is possible to create asynchronous Actions and Conditions. You can call asynchronous methods from Actions and Conditions using the await keyword. Such methods will be the most effective if you use asynchronous methods of the WorkflowRuntime object, for example, ExecuteCommandAsync instead of ExecuteCommand, or SetStateAsync instead of SetState, etc. You can create asynchronous Actions in Designer. To do that you simply need to check the Async checkbox in the Action or Condition where you're going to call asynchronous methods from. If you use IWorkflowActionProvider, then you will need to implement 4 additional methods. bool IsActionAsync(string name) and bool IsConditionAsync(string name) should return true so that the Action or Condition are called asynchronously. The execution of an asynchronous Action or Condition is done in the Task ExecuteActionAsync(string name, ProcessInstance processInstance, WorkflowRuntime runtime, string actionParameter, CancellationToken token) and Task<bool> ExecuteConditionAsync(string name, ProcessInstance processInstance, WorkflowRuntime runtime, string actionParameter, CancellationToken token) methods.
  • Parameters conveyed to the process with the command no longer need to be described as command parameters. If such a parameter is described in the scheme, it will be a Temporary or a Persistence one, depending on which Purpose is specified in the scheme. If the parameter is not described in the scheme, it will be a Temporary one.
  • The ExecuteCommand and ExecuteCommandAsync methods return information on whether the command has been executed (it may not be executed under certain conditions) and the ProcessInstance state after the execution of a command.

The following additional actions must be taken to upgrade to Workflow Engine 2.2:

  • If you use IWorkflowActionProvider, you will need to add 4 new methods to it: IsActionAsync, IsConditionAsync, ExecuteActionAsync, ExecuteConditionAsync. If you do not yet intend to use asynchronous Actions, then the IsActionAsync and IsConditionAsync methods should always return false, whereas ExecuteActionAsync and ExecuteConditionAsync can throw a NotImplementedException.
public bool IsActionAsync(string name)
return false;

public bool IsConditionAsync(string name)
return false;

public async Task ExecuteActionAsync(string name, ProcessInstance processInstance, WorkflowRuntime runtime, string actionParameter, CancellationToken token)
throw new NotImplementedException();

public async Task<bool> ExecuteConditionAsync(string name, ProcessInstance processInstance, WorkflowRuntime runtime, string actionParameter, CancellationToken token)
throw new NotImplementedException();


May 16, 2018

  • Workflow Engine for .NET Core App 1.1 is released. All Workflow Engine functions are supported. This version will be updated simultaneously along the .NET Framework version. 2 persistence providers are currently supported: MS SQL Server and PostgreSQL. Links to NuGet packages and samples can be found here.
  • Workflow Engine scheme import/export to/from BPMN2 has been added.
  • Bulk process creation has been added. Now you can create a large amount of processes (100 - 100,000) in significantly less time than when using the CreateInstance method. Use the _runtime.BulkCreateInstance(..) method to do that. Currently, the feature is available in the .NET Framework version of Workflow Engine and supports only MS SQL Server. The list of supported databases will be expanded.


  • Designer UI has been improved, transitions are now linear for better usability
  • Scheme rendering library KineticJS has been replaced with Konva.js
  • WorkflowDesigner.readonlymode(), WorkflowDesigner.printablemode() and WorkflowDesigner.ediatblemode() methods have been added to WorkflowDesigner object in the client. readonlymode makes Designer uneditable. printablemode removes the toolbar, the grid and all controls, zooming designer so that the scheme occupies the entire canvas. This mode can be used to print Designer's viewport to a PDF within a browser. editablemode makes Designer editable.
  • Designer now allows users to make an autocomplete list for the following fields: Actor.Value, Activity.Implementation.Action parameter, Transition.Condition.ActionParameter. The autocomplete list is being populated server-side via the IDesignerAutocompleteProvider interface and by transferring implementation to the WorkflowRuntime object via _runtime.WithDesignerAutocompleteProvider(provider).
  • The GetConditions method has been added to the IWorkflowActionProvider interface. Now, the choice of conditions and actions in Designer can be split.
  • Parameters of any type not mentioned in the scheme can now be used in Actions' code. The type should be serialized in JSON. Three methods are available: _processInstance.SetParameter("parameterName",parameterValue,ParameterPurpose.Persistence), _processInstance.GetParameter<ParameterType>("parameterName") and _processInstance.RemoveParameter("parameterName").
  • Ability to create Timers with a value which is undefined at the time of creation of a process has been added. Timer.Value == -1 means that the current transition will not be executed until the respective timer has a defined value. Timer.Value == 0 means that in case the timer connected to a transition does not have a value, this transition shall be processed automatically. Initial value of a timer can be set with the _runtime.NeedTimerValue event.
  • Ability to modify execution time for timers in running processes has been added. Use methods _runtime.SetTimerValue(processId,timerName,newValue) and _runtime.ResetTimerValue(processId, timerName) to change and reset timer values outside the process. Use methods _runtime.SetTimerValue(processInstance,timerName,newValue) and _runtime.ResetTimerValue(processInstance, timerName) to change and reset timer values from within your Actions.
  • Newtonsoft.Json version has been changed from 7.0.1 to 9.0.0.

The following additional actions must be taken to upgrade to Workflow Engine 2.0:

  • Replace the link to KineticJS with the link to konva.min.js. Konva.js library is included in the ZIP archive and in nuget package WorkflowEngine.NET-Designer.
  • Update Newtonsoft.Json.dll to 9.0.0. The library is included in the ZIP archive and in nuget package WorkflowEngine.NET-Core.
  • If you use implementation of IWorkflowActionProvider you should add a public List<string> GetConditions() method to it. It is advisable that the GetActions returns only the list of available Actions, whereas the GetConditions method should return the list of available Conditions. In this case they should be filtered properly in the Designer. However, if you do not want to modify your code, make sure that the GetConditions method throws a NotImplementedException. In this case, everything should work as it used to.
  • IF you use Oracle, you should run an update_1_5_to_2_0.sql script from the Oracle provider ZIP archive or a NuGet package.


  • Two new persistence providers were added to WorkflowEngine.NET Redis Provider for Redis and Ignite Provider for Apache Ignite
  • notrendertoolbar property was added to the Designer object configuration (client side javascript). You can hide toolbar in the workflow designer for end users.
  • Second parameter which allow ignore AutoSchemeUpdate sign of Activity was added to the WorkflowRuntime.UpdateSchemeIfObsolete method.
  • Several redundant operations related to subprocess features were removed to increase performance.
  • Conditions are checked for transitions that creating subprocesses.


In this release several features have been added to simplify the generation of forms based on commands.

  • The sign IsRequired for command parameter. You can take it into account when generating forms, also it is used in the command validation before the execution of command.
  • The Default value for command parameter. You can access it using CommandParameter.DefaultValue property, after you have received the list of available commands. You can set all command parameters to default value using WorkflowCommand.SetAllParametersToDefault or WorkflowCommand.SetParameterToDefault functions. The Default value must be a valid JSON (which can be deserialized to type which is specified in the bond Parameter) or will be interpreted as a string.
  • An autocompete was added in the field Type of Parameter (editing window Parameters). It makes a suggestions about types which can be used such as primitive types (Int32, String etc.) or your custom types. Types from assemblies which was registered using _runtime.RegisterAssemblyForCodeActions function are added in the autocomplete list. To prevent registration or filter the list you can use the last two optional parameters of _runtime.RegisterAssemblyForCodeActions function - ignoreForDesigner and designerTypeFilter.
  • The Initial values were added for Parameters. You can yse Initial value only for Parameters which have Purpose = Persistence. This values must be a valid JSON (which can be deserialized to type which is specified in the bond Parameter) or will be interpreted as a string. These values will be set to the process when it is created.
  • The JSON editor was added for edit Parameter.InitialValue (Parameters window), Command.InputParameters.DefaultValue (Commands window), Actor.Value (Actors window), Activity.Implementation.ActionParameter (Activity window), Transition.Condition.ActionParameter (Transition window). The JSON editor includes a syntax highlight and Format button. The Format button can be used to format your JSON. Please note that if you use JSON with unquoted property names, you must add reference on json5.js library on Designer page. For Parameter.InitialValue (Parameters window) and Command.InputParameters.DefaultValue (Commands window) the JSON editor aso includes Create button. This button can be used to create an empty object based on Parameter.Type. Designer (on server) uses only parameterless constructor to create the empty object.
  • There are two new events was added to WorkflowRuntime. Both are occurred only in normal execution mode (not in pre-execution). BeforeActivityExecution - is occurred after the Runtime has chosen an appropriate transition for execution but before Actions in an Activity were executed. ProcessActivityChanged - is occurred after some Activity was executed. You can use ProcessActivityChanged.TransitionalProcessWasCompleted property to ensure that the command (or timer) execution was finished. Using of these events could be more convenient than ProcessStatusChanged in some cases.
  • GetAllActorsForCommandTransitions(ProcessInstance) method was added to WorkflowRuntime. You can use this method to get next potential approvers for current state.
  • You can change the JSON Serializer settings for Parameters serialization using SetParameterSerializerSettings configuration method.


  • Schema was added in constructors of all SQL providers. For MsSQL the default schema is "dbo". For PostgreSQL the default schema is "public". For Oracle the default schema is null.
  • You are able to specify an interval timer value with milliseconds, seconds, minutes and days. For example "1d 2h 4m 30s" - one day two hours four minutes thirty seconds or "5m 30s", "14d", "12h", "10m", "10s" etc. You are able to use following names. d, day or days to specify interval in days. h, hour or hours to specify interval in hours. m, minute or minutes to specify interval in minutes. s, second or seconds to specify interval in seconds. ms, millisecond or milliseconds to specify interval in milliseconds. If the interval is specified as just a numeric value, it is interpreted as the interval in milliseconds.
  • You are able to pass initial parameters of a process by using _runtime.CreateInstance(CreateInstanceParams createInstanceParams) method. Parameters passed in the createInstanceParams.InitialProcessParameters property will be used as initial for parameters of a process.


  • The JSON serializer used by the engine was changed from ServiceStack.Text to Newtonsoft.JSON. 1.5.3 version of the Workflow Engine was built with the verion 7.0 of Newtonsoft.JSON.
  • MSSQL provider was rewritten from LINQtoSQL to ordinary SQL queries.
  • The Parameter window in the designer was improved. Now you can hide System parameters. They are hidden by default.
  • Working with types in the Parameter window in the designer was improved. Now you are able to use short type's names such as String, Guid, Int32 etc. for primitive types. The type names including namespace for custom types ( OptimaJet.Workflow.Core.Model.ActivityDefinition, Business.Approvers etc.)- Also you are able to use <> for generic types and [] for arrays.
  • Fixed a bug in the timers for their correct restart after restart of the workflow runtime.


  • ExecutedActivity and ExecutedTransition properties added in ProcessInstance class. Via them, you can access executed transition and activity during a transitional process.
  • A scheme of a process downloaded from the designer with not encoded Code Actions. You can upload a scheme with encoded or not encoded code actions.
  • The algorithm of sub-process scheme separation improved for it to work properly with the different schemes.
  • GetAvailableCommands method returns distinct commands.
  • Fixed parsing of the values of the Timers in different cultures
  • While merging the processes you can access the parameters of a subprocess using the property MergedSubprocessParameters of the ProcessInstance class.