XAF Logic Explainer

Teach your AI coding agent what your XAF application actually does.

See how it works →

Point it at an XAF module. It reads your entities, controllers, actions, business rules,
navigation and Model Editor customizations straight from source — and hands the result to
whatever agent you code with.

Why this exists

DevExpress has done excellent work making AI agents fluent in XAF. Two pieces already exist,
and this is the third:

An agent that has read every page of the XAF documentation still does not know that your Invoice
total is calculated from its lines, that ApproveController refuses to run when the period is
closed, or that three columns were hidden in the Model Editor and appear in no C# file at all. It
will confidently invent all three.

That gap is not solvable by better prompting. It is solvable by extraction.

These tools compose. Install the DevExpress skills for framework knowledge, use the Docs MCP
for the official reference, and use this for your own codebase. None of them replaces the others.

What it extracts

Everything below is read as syntax, using Roslyn. Your project never has to compile, and this
tool never links against DevExpress assemblies:

• Entities — properties, types, associations, and the XAF attributes that give them meaning
  ([Association], [Aggregated], [RuleRequiredField], [Appearance], [ModelDefault], …).
  XPO and EF Core, auto-detected from your using statements.
• Controllers and actions — SimpleAction, PopupWindowShowAction, SingleChoiceAction,
  their target criteria, and the handler code that runs when they fire.
• Business rules — validation attributes and code rules, with the conditions attached.
• Module setup — ModuleUpdater seed data and what gets created on first run.
• Navigation — the groups and items your users actually see.
• Model Editor (.xafml) — the customizations that exist only in XML and are invisible to
  anyone reading your C#. Module and platform files are merged the way XAF merges them.
• Custom property and list editors — including the JavaScript they cannot work without, and
  built-in editors reconfigured at run time through View.CustomizeViewItemControl<T>(). These
  live in the platform project beside the module, so nobody reading the business objects meets
  them.
• Version-gated migrations — the CurrentDBVersion < new Version(…) blocks in your updater.
  Each runs at most once for any database, and is the only explanation for data the current code
  cannot account for.
• Every screen, and what loads onto it — see below.

These are the reason an agent that has read every business class can still be confidently wrong
about the application:

What runs when you open this screen

Nothing in an XAF repository answers that, and both halves are missing for different reasons.

The screens themselves are in no file. XAF generates a list, a detail and a lookup view for
every business class, plus a list view for every collection, and the Model Editor stores only the
ones somebody changed. Grepping your source for Patient_Prescriptions_ListView finds nothing —
and that is not evidence it is missing.

Which controllers run there is decided at run time, by four conditions XAF ANDs together:
nesting, view type, object type and view id. Each is unrestricted when unset, so a controller that
sets none of them loads onto every screen you have.

This reads all four the way ViewController.IsFitToView evaluates them, against a view inventory
built from the framework's own id generators — and records why each one matched, so the answer
can be checked rather than trusted:

Two layers, kept apart. What your team wrote gets the full treatment; what XAF provides is folded
away behind one line, because there is a great deal of it and it is not yours to change. With a
ground-truth catalog it is named too — scoped to
the modules you actually register, so a WinForms controller never appears on a Blazor screen.

What it will not claim: a controller listed here can still switch itself off through
Active["reason"], which depends on the data and the user. This is what XAF loads onto a
screen, not what will necessarily do something — and anything it could not read from the source is
listed apart, with the reason, instead of being quietly treated as "runs everywhere".

Quick start

dotnet tool install -g XafLogicExplainer.Cli

xaflogic agents --project "C:\MySolution\MyApp.Module"

That writes AGENTS.md, CLAUDE.md and .github/copilot-instructions.md at your solution root.
No account, no API key, no server. Your agent understands the application on its next question.

What it writes, and why it is split in two

AGENTS.md is prepended to every request an agent makes in the repository, so its cost is paid
forever. Dumping 70 KB of entity detail there would crowd out the actual question. So the output is
tiered:

The most valuable part is the smallest. AGENTS.md opens with ground rules — that this
application uses XPO and never EF Core, that the inventories are complete so anything absent
genuinely does not exist, and that some behavior lives in the Model Editor rather than in C#. Those
few paragraphs stop most of the confident invention agents produce about unfamiliar XAF codebases.

Existing files are never clobbered: generated text lives between markers, anything you wrote by
hand is preserved, and regenerating is byte-identical when nothing changed.

Or let the agent ask questions directly

Generated files are a snapshot. The MCP server is a live connection — the agent queries your
application while you work on it, and cannot go stale.

/plugin marketplace add peopleworks/XAFLogicExplainer
/plugin install xaf-logic-explainer@peopleworks-xaf

That installs a skill and an MCP server in one step. For any other MCP client, either run it
straight from NuGet with no install:

{
  "mcpServers": {
    "xaf": { "command": "dnx", "args": ["XafLogicExplainer.Mcp", "--yes"] }
  }
}

…or point at the CLI if you already have it:

{ "mcpServers": { "xaf": { "command": "xaflogic", "args": ["mcp"] } } }

Started from a solution directory it finds the XAF module by itself, so neither form needs a path.

Ask for something that isn't there and the answer is the useful one:

There is no entity called 'PurchaseOrder' in this application.
This is the complete list of 19 entities, extracted from the whole source tree: …
If the user expects 'PurchaseOrder' to exist, it has not been created yet.

Pair it with the official DevExpress skills. /plugin install dx-xaf@DevExpress-agent-skills
teaches how XAF works; this teaches what your application does. An agent with only the first will
write correct XAF against entities you do not have.

The same knowledge, for a person

An agent reads AGENTS.md or queries the MCP server. Someone who has just inherited a ten-year-old
XAF application needs the same facts arranged very differently:

xaflogic explain --project "C:\MySolution\MyApp.Module" --open

One HTML file. No server, no build step, no request to the network — it opens from an email
attachment on a machine with no internet, which is how handovers actually happen.

It draws a map of your domain model from the association attributes scattered across your
codebase. Most teams have never seen theirs: it exists in one person's head, which is exactly the
knowledge that leaves when they do.

_{Real output, from the sample application in this repository. Hover an entity and everything it
does not touch fades; purple means deleting the parent deletes the child.}

Alongside it: every entity and what each property is, every action with the code it runs,
validation with the message the user will actually see, and the Model Editor settings that appear
in no C# file.

And an index of every criteria expression in the application — a dialect that is neither SQL
nor C#, gathered from attributes spread across the source and otherwise collected nowhere:

Try it on the sample without touching your own code:

xaflogic explain --project tests/XafLogicExplainer.Tests/Fixtures/DemoSolution/PharmacyDemo.Module --open

Optional: tell your code apart from DevExpress's

Extraction reads your source without knowing anything about the framework it is written against,
which leaves one question unanswerable: is DeleteObjectsViewController something your team wrote,
or something DevExpress ships? Without an answer, generated documentation presents framework
behavior and your own logic as the same thing.

If you have a DevExpress licence:

xaflogic catalog build

That reads your own installation and records what XAF itself provides — attributes, controllers,
model interfaces and modules, with the official summaries and documentation links DevExpress ships.
On DevExpress 26.1 that is around 850 framework types.

If you also installed the DevExpress source code component, it records where each framework
controller activates — the four conditions XAF checks before running it. That cannot be read from
the assemblies: four out of five built-in controllers set their target inside a constructor. Pass
--dx-sources <Components/Sources> if they are not beside your assemblies.

Extraction then picks it up automatically and can say things it otherwise could not:

• "ArchiveController extends the built-in DeleteObjectsViewController" — you are changing how
  deletion works application-wide, not adding a feature beside it.
• "[AuditedByFinance] is not an XAF or .NET attribute" — your team invented it, so its meaning
  lives in this codebase and in no documentation anywhere.
• "32 framework controllers also load onto this screen" — named, with what each one does, and
  scoped to the modules your application actually registers, so a WinForms controller never appears
  on a Blazor screen.

The catalog is written to ~/.xaflogic/catalog/, never into your repository: it is derived from
licensed software. Everything works without it — it only sharpens the output. See
NOTICE.md.

Commands

Documentation is generated in English or Spanish (--lang en|es).

Useful flags: --orm auto\|xpo\|efcore, --lang en\|es, --enrich (AI-generated business-logic
summaries per controller and action), --force, --all.

Extraction is incremental — a SHA-256 over your .cs and .xafml files means an unchanged
project is a no-op. There is an MSBuild .targets file if you want it to run on build.

Status

v0.14.0. The extraction engine is the mature part: it runs in production against real XAF
applications. The agent-facing surface is what is landing now, in the open.

PeopleWorks Copilot, where this tool grew up, is now one sink among several rather than the
destination everything was built around. The outputs that matter most need no server at all.

The long version

Why a third of an XAF application's behaviour lives outside its business classes, the four places
it hides, and what the extracted output actually looks like:

• Your coding agent knows XAF. It has never seen your application.
• Tu agente de código sabe XAF. Nunca ha visto tu aplicación. — en español

Each is written in its own language rather than translated from the other. Sources in
docs/Blog/.

Repository layout

src/
  XafLogicExplainer.Core                 Roslyn extraction engine — no DevExpress reference
  XafLogicExplainer.Mcp                  MCP server (ModelContextProtocol 2.1)
  XafLogicExplainer.Cli                  the `xaflogic` command
  XafLogicExplainer.CopilotSync          PeopleWorks Copilot target + AI enrichment
  XafLogicExplainer.DescriptionAnnotator generates missing [Description] attributes
  XafLogicExplainer.Blazor               in-app help panel for XAF Blazor apps
plugins/
  xaf-logic-explainer                    the installable Claude Code plugin

Built on .NET 10.

Only XafLogicExplainer.Blazor references DevExpress packages; it needs the DevExpress NuGet feed
and a license to build. Everything else builds anywhere, which is why CI can verify it for free.

Contributing

The single most valuable contribution is telling us what the extractor missed. XAF is enormous,
every codebase uses a different slice of it, and no single project exercises the whole framework.
There is an extraction-gap issue template for exactly
this: show the XAF pattern your project uses and what the tool failed to see.

See CONTRIBUTING.md. Bug reports, docs and translations are equally welcome.

License

MIT. See NOTICE.md for the relationship to DevExpress.

An independent community project — not affiliated with, endorsed by, or supported by
Developer Express Inc. It contains no DevExpress source code and needs no DevExpress license to
build or run. DevExpress, XAF and eXpressApp Framework are trademarks of Developer Express Inc.

Built by Pedro Hernández (PeopleWorks),
Microsoft MVP for .NET —
for the DevExpress and XAF community.