992 · Workflow Engine by Optimajet · v22.1.0 stable · August 2026 · .NET 10 down to .NET Framework 4.6.2 · Last updated
A workflow engine for .NET with the HTML5 Workflow Designer. It runs as an in-process library, a HTTP API, or a standalone server with the same schemes in each. Processes persist in your own database, survive restarts, run on timers, keep an audit trail, and version without breaking running instances. Shipping inside commercial CRM, ERP, document, HR, and case management products since 2014.
Releases, samples, and issues are available on GitHub. Full engine source access is available with selected editions under a commercial EULA.
All four products are self-hosted and never connect to Optimajet. They run on-premise or in your own cloud, with your own database, and check the license key locally. Learn on Workflow Engine Free, then move to Workflow Engine for your company's internal apps. If you embed the engine in a public web app, SaaS or a product you ship, you need Workflow Engine NEO. And if you would rather run a workflow service than embed one, there is Workflow Server, a standalone app that ships as a Docker image.
I want to try it first
Formerly Community Edition, it is the same .NET library as Workflow Engine, for personal, non-commercial use, with no license key and no time limit.
I am adding workflow to our internal .NET apps
You install the commercial .NET library from NuGet, call it from your C# code and keep process state in your own database. Team and Complete are perpetual licenses for your company's internal apps.
I am adding workflow to a public web app or SaaS
It adds an HTTP API to your ASP.NET Core app on .NET 8 or 10. Business covers internal apps, Subscription and SaaS a public web app or SaaS, and Enterprise adds OEM. Try it with a free trial key.
I want to run a workflow service, not embed a library
Built on Workflow Engine NEO, it ships as a Docker image and runs as its own service. Any app calls it over HTTP. It reaches your actions, conditions and rules through the Callback API or a C# plugin.
Workflow Engine Free, Workflow Engine, and Workflow Engine NEO are the embeddable .NET path. Workflow Server is the standalone application path.
Moving up from Workflow Engine Free, or from Workflow Engine to Workflow Engine NEO, takes a license key, not a rewrite. Schemes carry over between all four products, and older schemes keep working, as long as the actions and plugins a scheme uses are available where it runs.
Among commercial workflow engines, on the three terms that decide what a SaaS product pays.
You pay for the license, not a share of revenue.
The bill does not move with process volume.
We do not cap distribution of the product you build.
The license covers the product, not the size of the team building it.
The engine keeps no user store, so your application’s users are never counted.
Process data lives in your database, where nobody meters it.
One license covers one software product. Public SaaS use comes with NEO Subscription, NEO SaaS or NEO Enterprise, while Team, Complete and NEO Business are licensed for internal commercial use. Redistributing the engine itself is OEM, a NEO Enterprise right. Workflow Engine pricing and editions
Workflow Designer speaks Simple Process Notation, the engine's own flowchart language. BPMN has more than 50 element types. Here there are only three. Activities are the states, Transitions are the arrows, and commands move the process along. There is nothing else to learn, because branching and timers are just settings on a transition. Anyone who can read a flowchart can read this canvas. And the diagram is not a picture. It is the scheme the engine runs. Below is the Vacation Approval process from the demo application.
The full notation is in the Simple Process Notation documentation. Draw and run schemes like this one in Workflow Designer, embedded in your own application.
Everything below is code your team does not have to write. Install the package and start on the parts that make your product different.
HTML5 drag-and-drop scheme editor, embedded in your UI. npm packages for React, Angular and vanilla JS, and a documented Blazor path.
Bring diagrams from any BPM tool that exports BPMN 2.0. Import only, no export back. Analysts model, developers ship.
The Forms Plugin binds forms to workflow activities. It is an add-on for the Workflow Engine Complete edition and included in every edition of Workflow Engine NEO. Form Engine Core is MIT-licensed. The Form Engine Enterprise license covers Form Engine Designer and the other features of that edition; Workflow Engine NEO Enterprise includes it with OEM rights.
Core TenantId storage with every Workflow Engine license. Ready multitenancy across the built-in Workflow Engine HTTP API operations in NEO.
MS SQL (plus Azure SQL and Managed Instance), PostgreSQL, MongoDB (plus Azure Cosmos DB), MySQL, Oracle, SQLite. Auto migrations via FluentMigrator. Your schema, your stack.
No user store in the engine. One interface, IWorkflowRuleProvider, hands every command check to your LDAP, Active Directory or custom identity system.
Eight plugins ship, three of them inside the Core package. Your own take the same path: implement IWorkflowPlugin, register it in one line.
Write C# transition logic inside the Designer. Compiled dynamically at runtime, so changing behavior needs no redeploy.
Modify a scheme while processes are running. The engine validates and applies the change on the next call.
Call AsMultiServer(), share one database, scale horizontally. Distributed locking, timers, recovery built in.
Durable timers that survive restarts. Wait days, weeks, or months for an event without polling code.
Every transition is persisted with actor, timestamps, and duration. Inbox, outbox, and approval history ship out of the box.
Five concepts cover the whole model: activities, transitions, commands, timers, actors. Learn it in weeks, not the months a full BPMN platform takes.
SetState, SetActivity, and Resume move any process to any state, with or without executing actions. Recover a stuck process without touching the database.
Simulation mode that walks the route ahead without changing process state: show users the coming approval stages and who signs, before they submit.
Specially marked transitions spawn subprocesses that run in parallel, act independently, and merge back into the parent process state.
Integrating Workflow Engine into a .NET application takes about an hour: set up the database, initialize WorkflowRuntime, connect the Designer, create a scheme, and execute your first commands. Each guide below starts from a need teams bring to the engine and opens the documentation page that answers it.
Start with WorkflowRuntime initialization, basic operations, designer setup, persistence, commands, actions, rules, timers, and process history.
Open docsOpen the HTTP API overview for the RPC, Data, and Search endpoints, then the multitenancy, pluggable security, and workflow forms pages for the capabilities included with Workflow Engine NEO (v19.0.0+).
Open docsReview the Approval Plugin, inbox / outbox patterns, parallel approval, comments, forms, and role resolution.
Open docsCompare Workflow Server for HTTP API, admin console, Docker-ready deployment, users, roles, and OpenID.
Open docsAI can classify, extract, summarize, recommend, or call external tools. Production business software still needs state, permissions, timeouts, human review, auditability, and fallback paths. Workflow Engine governs AI-assisted business processes through explicit actions, rules, timers, commands, and transition history.
Treat this as an implementation pattern, not a separate agent orchestration product. AI participates in the workflow, but the workflow defines what is allowed, visible, reviewable, and recoverable.
Let AI classify, extract, summarize, or propose the next step while Workflow Engine controls allowed commands, transitions, rules, and approvals.
Coordinate AI calls, external services, and human reviewers inside an explicit process with ordering, branching, timers, and fallback transitions.
Keep autonomy under oversight. Approvals, review, escalation, and resume-after-human-input become workflow steps, not ad-hoc emails.
Make AI-assisted behavior inspectable as part of the business workflow: states, commands, transitions, parameters, timers, and history stay visible.
Four shapes cover most of what .NET teams bring to a workflow engine: a decision that needs a person, a tenant boundary, a process that has to wait, and a chain of calls into other systems. Business process automation inside a .NET product is usually some combination of them, and each one is a scheme you draw once and run on your own database.
A purchase order, a contract, an invoice: someone has to sign off before the record moves on. Approval automation replaces the chase of status emails with a scheme that names the reviewers, the order they review in, what happens on a rejection, and who is allowed to act at each step.
Parallel approvalYour product serves many customers, and each one wants its own version of the same process. Tenants are isolated physically, logically, or both in one deployment, and a new tenant is registered without a restart. The separate Workflow Engine NEO product provides full multitenancy.
MultitenancyA process that waits hours, days, or months for an answer from a person or another system. State lives in your database, not in application memory, so workflow automation for long-running processes survives a restart, scales across servers, and picks up where it stopped when the timer fires or the reply arrives.
Durable executionOperations that run across files, records, and remote services, in sequence or in parallel. The scheme calls an HTTP endpoint, moves a file, starts a subprocess, and branches on the result. Anything the built-in activities do not cover becomes a custom activity in reviewed C# code.
HTTP requests
€100K
Saved annually
50,000
Workflows automated
LKS Next, a multinational technology services firm, replaced a hand-rolled approval system with Workflow Engine to standardize processes across four legal entities in different countries, without imposing a single tech stack across regional teams.
Workflow Engine for enterprise teamsSelected quotes from public reviews. Each one is tied to a verified user and links back to the platform it was left on.
The HTML5 designer is exceptional. The product offers excellent plugins and documentation, along with a wide range of customization possibilities.
Lavrentios Penklidis
CBDO, Adnow Media
We found it very easy to embed it into our ASP.net core based solution. The documentation was very good and the sample was comprehensive.
Sanjeev Musafir
Partner, Dataview Consulting
Excellent feature set. Good support and documentation. We were satisfied with everything, no real flaws identified.
Vlad Shchelkunov
Founder, Bonvivants
It is robust and get the job done. Designing workflow is easy to use and interface is user friendly. Overall very happy as a customer.
Manish Hingorani
Head of IT, Acer Computer Australia
Integrating with existing application was very easy. Documentation was very thorough, and support was helpful.
Scott Goodin
VP Software Engineering, TADERA
OptimaJet provides a robust and versatile software product and backs it up with excellent support. Adding the workflow engine has been a tremendous value to our company.
David Nickelsen
Director of Software, CivicServe
The HTML5 designer is exceptional. The product offers excellent plugins and documentation, along with a wide range of customization possibilities.
Lavrentios Penklidis
CBDO, Adnow Media
We found it very easy to embed it into our ASP.net core based solution. The documentation was very good and the sample was comprehensive.
Sanjeev Musafir
Partner, Dataview Consulting
Excellent feature set. Good support and documentation. We were satisfied with everything, no real flaws identified.
Vlad Shchelkunov
Founder, Bonvivants
It is robust and get the job done. Designing workflow is easy to use and interface is user friendly. Overall very happy as a customer.
Manish Hingorani
Head of IT, Acer Computer Australia
Integrating with existing application was very easy. Documentation was very thorough, and support was helpful.
Scott Goodin
VP Software Engineering, TADERA
OptimaJet provides a robust and versatile software product and backs it up with excellent support. Adding the workflow engine has been a tremendous value to our company.
David Nickelsen
Director of Software, CivicServe
The HTML5 designer is exceptional. The product offers excellent plugins and documentation, along with a wide range of customization possibilities.
Lavrentios Penklidis
CBDO, Adnow Media
We found it very easy to embed it into our ASP.net core based solution. The documentation was very good and the sample was comprehensive.
Sanjeev Musafir
Partner, Dataview Consulting
Excellent feature set. Good support and documentation. We were satisfied with everything, no real flaws identified.
Vlad Shchelkunov
Founder, Bonvivants
It is robust and get the job done. Designing workflow is easy to use and interface is user friendly. Overall very happy as a customer.
Manish Hingorani
Head of IT, Acer Computer Australia
Integrating with existing application was very easy. Documentation was very thorough, and support was helpful.
Scott Goodin
VP Software Engineering, TADERA
OptimaJet provides a robust and versatile software product and backs it up with excellent support. Adding the workflow engine has been a tremendous value to our company.
David Nickelsen
Director of Software, CivicServe
Leading companies rely on Workflow Engine by Optimajet to run business processes that cannot fail.
The workflow is super flexible, visual and easy to extend, allowing us to customize it to our needs in a timely fashion.
Márcio Lima
Senior Software Engineer, Wine.Create
Straight answers to the questions .NET teams ask while choosing a workflow engine: licensing, products, and how this engine differs from Temporal, Camunda, and Elsa.
Workflow Engine by Optimajet is an embeddable .NET workflow engine, workflow automation software for adding stateful business processes to .NET applications. It includes Workflow Runtime, HTML5 Workflow Designer, persistence providers, commands, rules, actions, timers, parameters, plugins, process logs, and transition history. The current stable release is v22.1.0 (August 2026), and the canonical NuGet package is WorkflowEngine.NETCore-Core.
The Workflow Engine family includes a free product, Workflow Engine Free, for evaluation, proof of concept, and learning under a personal, non-commercial license. It is limited to 10 schemas and 4 execution threads, with no caps on activities, transitions or commands per schema. Commercial licenses are sold per product as a perpetual on-premise license, with a subscription option also available. There are no royalties and no per-execution fees.
The engine already provides the infrastructure a homegrown solution would need years to reach: visual scheme editing, runtime execution, persistence across six database providers, timers, commands, rules, actions, process parameters, history, plugins, and integration points for C# business logic and authorization. Your team writes domain logic instead of building a designer, a scheduler, persistence, and an audit trail.
No. Workflow Engine and Workflow Engine NEO are separate products in the same product family. Workflow Engine NEO is based on Workflow Engine and, since v19.0.0, every edition of Workflow Engine NEO includes the Data API, RPC API, full-fledged multitenancy, the WorkflowApiPermissions claim model, and the Forms Plugin. Workflow Engine has Team and Complete editions; Workflow Engine NEO has Subscription, Business, SaaS, and Enterprise editions. Forms is also available as an add-on for the Workflow Engine Complete edition.
Workflow Server is a separate standalone application built on the Workflow Engine library: it ships with an HTTP API, an administrative console, Docker-ready deployment, built-in users, roles, and OpenID integration. Choose it when a turnkey workflow service is preferred over embedding a .NET library into your own application.
Yes, as an implementation pattern. AI or external decision services can be called from controlled workflow actions while Workflow Engine keeps state, commands, rules, timers, review steps, and transition history explicit. Workflow Engine is not positioned as a standalone agent orchestration platform.
Workflow Engine embeds into a .NET application as a NuGet package and needs no extra infrastructure; Temporal and Orkes run as separate clusters operated alongside the application. Workflow Engine includes a visual HTML5 designer business users can drive; Temporal and Orkes are code-first platforms. Where massive polyglot distributed fan-out is the requirement, a dedicated orchestration cluster is the better fit.
Workflow Engine is the .NET-native path: it embeds in-process with no JVM and no separate platform to operate, and imports BPMN 2.0 diagrams as native engine schemes. Benchmarked on a high-performance server, Workflow Engine handles 250 operations per second, with Camunda at 150 to 200 process instances per second on similar hardware. Learning the engine typically takes weeks, versus months for Camunda with BPMN.
Workflow Engine has been shipping in production .NET applications since 2014. A decade of maturity is the differentiator vs. Elsa Workflows (first major release in 2019). Both are .NET libraries with a workflow designer, while the separate Workflow Engine NEO product provides the Workflow Engine HTTP API and full multitenancy. Optimajet also offers separately purchased support plans with committed response times and plugins for Approval, BPMN, Active Directory / Entra ID, and Forms. Elsa is community-maintained open source; Workflow Engine and Workflow Engine NEO are commercial products with a vendor accountable on every support ticket.
Licensed engine-source access is unavailable on Team and NEO Subscription, a one-year add-on on Complete, NEO Business and NEO SaaS, and included for one year with NEO Enterprise, under a commercial EULA. The public repository at github.com/optimajet/WorkflowEngine.NET hosts releases, samples, and issues. Full engine source access is a separate, edition-specific entitlement.
Build it in the designer, connect the commands to your C# code, and run it on your own database. The integration guide takes about an hour to follow. Workflow Engine Free works without a license key or a call with sales, and the same code runs in the paid editions if you decide to upgrade.
