Ask Codex, Claude or Cursor to wire a workflow library into a .NET service and you usually get code that looks right and calls a method that doesn't exist. Say the agent gets past that. It then hits the line "obtain a license key from the vendor" and stops, because that step was built for a human with a browser and an email inbox.
I work on Workflow Engine at Optimajet, and we've recently rebuilt our documentation. The new primary documentation is available at docs.workflowengine.io. It is gradually replacing the legacy documentation at workflowengine.io/documentation. It publishes its full text as a single file so an agent reads the whole thing in one request instead of guessing, and a trial key can now be obtained by an agent, without a human clicking through a form.
The rest is for humans: 57 pages, four sections, 24 feature pages, 17 pages that each define exactly one concept, plus the generated C# API reference on its own host, api.workflowengine.io, 1256 pages across 20 packages.
If you've never touched the product: Workflow Engine by Optimajet is an embeddable .NET library for workflow automation. You add a NuGet package to your app, point it at the database you already have, and it handles process state, transitions, timers, rules and actions in-process. Nothing extra to deploy, no separate workflow server to babysit. It works on .NET Framework 4.6.2 and up as well as modern .NET and ASP.NET Core, and it persists to SQL Server (2017+), PostgreSQL, MySQL, Oracle, SQLite or MongoDB, whichever provider package you install.
A quick note before anyone asks: Workflow Engine is commercial software with a free tier. It's not open source, but Enterprise customers can obtain the full source code as part of their license. We've been shipping it since 2014. The latest stable release is 22.0.0, released on July 16, 2026.
llms.txt is the index, every published page with a one-line description, about 11 KB.
llms-full.txt
The key is the other half. trial.workflowengine.io/llms.txt
carries instructions an agent can follow to obtain a trial license key by itself. Writing correct integration code and then stalling on paperwork is a stupid way to lose an evaluation, and it was the failure we kept watching happen.
The API reference host publishes an llms.txt
too. Bookmark api.workflowengine.io: it's the generated C# reference for all 20 packages (Core, six database providers, six plugins, the Migrator, and the Web API with its six provider packages). The main docs don't link to it yet, so browsing won't get you there. That one's on us, it's in the queue.
| Section | Pages | What it's for |
|---|---|---|
/evaluate/ |
||
| 30 | Deciding. 24 feature pages, the edition list, licensing and trial keys. | |
/get-started/ |
||
| 24 | Running it. Install, first workflow, designer integration, 17 concept pages. | |
/roadmap/ |
||
| 1 | What's next. | |
/video-tutorials/ |
||
| 1 | For people who'd rather watch. |
The feature pages are one page per capability, named the way the product names them: Visual Designer, Simple Process Notation, Process Versioning, Parallel Processes, Timers & Scheduling, Direct State Control, HTTP API, BPMN Support, Plugin System, Pluggable Security, Clustering, Multitenancy, Attachable Forms, Customization, Multi-Database Support, Bulk API, Work Calendar, Pre-Execution (Simulation), Process Logs, Workflow as Code, Database Versioning, Offline API, Interactive Designer, Workflow Templates.
The concept pages were the ones I most wanted to exist. Seventeen terms, one page each, no page trying to explain four things at once: activity, transition, command, scheme, process instance, workflow runtime, persistence, action, parameter, condition, rule, timer, annotation, process logs, localization, subprocess, work calendar. Workflow tools all use the same handful of words to mean slightly different things, and a shared vocabulary saves a lot of arguing.
Get Started is three short pages: install, define a scheme, start an instance. Here's the shape of it, with SQLite because it doesn't need a server running.
dotnet new webapi -n WorkflowApi --framework net10.0
cd WorkflowApi
dotnet add package OptimaJet.Workflow.Api
dotnet add package OptimaJet.Workflow.Api.Sqlite
Register the services and map the endpoints:
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddControllers().AddJsonOptions(ConfigureJson);
builder.Services.AddWorkflowApiSqlite();
builder.Services.AddWorkflowApiCore(SetupWorkflowApiCore);
builder.Services.AddWorkflowRuntime(SetupWorkflowRuntime);
var app = builder.Build();
app.UseRouting();
app.MapWorkflowApi();
app.Run();
You can write the scheme as XML, or draw it in the designer without installing the designer at all:
npx @optimajet/workflow-designer http://localhost:5274/workflow-api/designer Approval
That opens the full designer in a browser tab, wired to your local Web API. Save from there and the scheme goes into your database. Then start a process instance:
curl -X POST http://localhost:5274/workflow-api/rpc/create-instance \
-H "Content-Type: application/json" \
-d '{ "schemeCode": "Approval", "processId": "a3f5b2c1-4d6e-7f8a-9b0c-1d2e3f4a5b6c" }'
You need the .NET SDK 10.0 and a database for that path, and SQLite counts, it's just a file. Console apps and worker services have their own page, Framework-Agnostic Install. We didn't want ASP.NET Core to be a precondition for trying the library.
The license key you pass to WorkflowRuntime.RegisterLicense()
decides which edition you're running. Same package either way, so moving up a tier is a key swap, not a rewrite.
| Edition | License | Limits and additions |
|---|---|---|
| Workflow Engine Free | Perpetual, personal and non-commercial | 10 schemas, 4 execution threads, unlimited activities, transitions and commands, Optimajet branding in the designer, no key needed |
| Workflow Engine Team | Perpetual, internal commercial use | No schema limit, higher thread and command limits, single server, 365 days of updates |
| Workflow Engine Complete | Perpetual, internal commercial use | No usage limits, multi-server clustering, no designer branding |
| Workflow Engine NEO | Annual subscription | RPC and REST API, full hybrid multitenancy, clustering, forms integration |
| Workflow Engine NEO Business | Perpetual | NEO APIs, clustering, forms, without full hybrid multitenancy |
| Workflow Engine NEO SaaS | Perpetual | Full NEO set, plus Active Directory connector and BPMN import |
| Workflow Engine NEO Enterprise | Perpetual | All of the above, plus white-label canvas, OEM redistribution, the FormEngine React form builder, one year of source code access |
Details are on Workflow Engine Editions, key mechanics on License Key.
The documentation at docs.workflowengine.io is the new primary documentation for Workflow Engine. It is intended to replace the legacy documentation hosted at workflowengine.io/documentation/ over time.
The migration is still in progress. The new documentation already covers evaluation, installation, concepts, features, tutorials and API usage, but some reference material remains on the legacy site while it is being reviewed, updated and migrated.
At the moment both documentation sites are maintained. If a topic cannot yet be found in the new documentation, the legacy documentation remains the authoritative source for that section until migration is complete.
This is the section most docs announcements leave out, and it's the one that saves you a search.
Still on the old host at workflowengine.io/documentation/
:
Those pages are alive and correct, they just haven't been rewritten for the new site. And Workflow Server, which is a different product with its own license, documents itself at workflowserver.io/documentation/. Don't go hunting for it under the engine docs, it isn't there.
| You want | Page |
|---|---|
| Install into ASP.NET Core | |
/get-started/install-workflow-engine/ |
/get-started/framework-agnostic-install/
/get-started/create-your-first-workflow/
/get-started/integrate-the-designer/
/get-started/concepts/
/evaluate/workflow-engine-features/
What is Workflow Engine by Optimajet?
An embeddable .NET library for workflow automation. It's a NuGet package inside your application, using your database, running in-process. No separate workflow server.
Is Workflow Engine open source?
No. Commercial software with a free tier, under a commercial license. Workflow Engine Free is perpetual and needs no key, but it's personal and non-commercial use only, capped at 10 schemas and 4 execution threads.
Which databases does it support?
SQL Server 2017 and above, PostgreSQL, MySQL, Oracle, SQLite, MongoDB. You install the matching provider package and register it at startup.
Which .NET versions?
.NET Framework 4.6.2 and up, plus modern .NET and ASP.NET Core. The ASP.NET Core quickstart targets the .NET SDK 10.0.
Where is the documentation now?
Main docs at docs.workflowengine.io. Generated C# API reference at api.workflowengine.io. Web API setup and security, release notes, BPMN tables and database entity tables are still at workflowengine.io/documentation/. Workflow Server is at workflowserver.io/documentation/.
Can an AI agent read the docs?
Yes, that's what llms.txt
and llms-full.txt
are for, and the API reference host has its own llms.txt
. An agent can also get a trial key by following trial.workflowengine.io/llms.txt
.
Why not just write my own state machine?
Some teams should. The moment you need persistence, timers, rule evaluation, scheme versioning, clustering and a visual editor a business user can open, you're building a product next to your product. That's the trade we ask people to think about before adopting anything, ours included.
docs.workflowengine.io/get-started/ if you want code in front of you in the next quarter of an hour. docs.workflowengine.io/evaluate/ if you're still deciding whether an embedded engine beats rolling your own.
And if a page is wrong, missing or confusing, tell me in the comments. I'd rather hear it here than not hear it at all.