Application Explorer for Dynamics 365 Finance & Operations

Browse and read the local metadata of a Finance & Operations instance from VS Code — the Application Explorer tree, plus a search view that filters it.

Install

Build and install the .vsix:

npm install
npm run compile
npm run package
code --install-extension vscode-d365fo-tools-xpp-<version>.vsix

Press F5 to launch the Extension Development Host, then open the Application Explorer (Xpp) activity.

The views

Both live in the Application Explorer (Xpp) activity in the Activity Bar.

Application Explorer (Xpp)

The metadata tree, mirroring Visual Studio's Application Explorer.

• Three roots, all tolerant of missing or empty folders:
  • MS-UDE — the versions under d365fo.aot.ude.rootPath. A folder only becomes a version row if its name is a four-part version (10.0.2645.32) and it holds at least one model, so Logs, XPPConfig and RuntimeSymLinks never appear. A version with no models is dropped once the scan proves it.
  • MS-Packages — the models under d365fo.aot.rootPath.
  • Custom — one entry per path in d365fo.aot.custom.rootPath.
• Expanding a version lists its models. Each version row has a toggle switching between the models listing and a Classic view that mirrors Visual Studio's AOT: Data Types, Data Model, Code, User Interface … down to individual elements. Category and type names match Microsoft's Application Explorer resources exactly.
• The Classic view expands further: a category shows its types, a type shows its elements, and an element folds into its live XML outline — table sections with their child counts, base-enum values, form controls, data entity fields, workflow outcomes and so on.
• Clicking an element opens a read-only X++ source view, reconstructed from the XML on the fly with X++ syntax highlighting — our equivalent of VS's transient XppSource documents. The raw XML stays one right-click away.
• A query row is a special case: selecting it shows the Metadata overview of the query that backs it, which is the same page a view shows under its Metadata node.
• Right-click a row for its actions.

Row actions (right-click)

Where	Action
Version	Toggle Models/Classic View
Any row	Refresh
Model, element, enum value, table section, member	Reveal Model Folder in Explorer
Element	Open X++ Source · Show Raw Element XML · Show Properties · Resolve Field Types
Element, table section, member, XML node	Resolve Field Types

Models also carry an inline action that opens the model's Descriptor/*.xml.

Grids

Several actions open a table instead of the tree, and stay open behind the Extension Development Host while you work:

• Table fields — every field, with its type, id, label and relation keys. Views and data entities get their own grid, because their fields bind to a data source rather than declaring a type.
• Table relations, Table indexes and Metadata for a table.
• Enum values for a base enum, and labels for a label file.
• Properties for any element: name, label, help text, the group and menu items it belongs to, where the platform places it, and its cross-references.

Fields resolve their types by walking the whole chain — EDT, table field, base data type — and show the travel as a hover. Auto Resolve (d365fo.aot.autoResolve, off by default) resolves every field the moment you pick one. The resolve language comes from d365fo.aot.resolve.language (en-US by default).

AOT Search

A search view with a search box, a funnel and @ type filters above the whole tree — the same shell VS's Extensions view has.

• The tree is the answer. There is no separate result list, and no element index behind the page: the filter is applied to the tree itself, so expanding a node shows its real children, pruned.
• Filtering prunes this tree only. It never folds: whatever you have open stays open as you add and remove text.
• Right-click a row for its actions.

The funnel

The funnel opens on the four kinds you reach for most — Table, View, Class, Form — then an Advanced row opens the fourteen first-level nodes, and each node opens its own child types. Each node shows how many types sit under it, so you can see where the depth is before drilling in.

• Picking one of the four top kinds leaves no trailing space and keeps the menu open, so Advanced is one click away and narrowing from @Table to an exact type is two clicks rather than reopen-type-pick.
• A leaf type is the end of the road and closes the menu.

@ type filters

Type @ for the full list of options, navigable with the arrow keys: Home and End jump to the ends, Enter or Tab take the highlighted row, and Escape dismisses. A hand-typed @word never filters the list away — matches rank first and everything else stays below them, ready to arrow down to, so a half-typed word is never a dead end.

Picking a type puts its @token in front of whatever you have typed and replaces any other type token:

You type	You get	Means
@Table custtable	@Table CustTable	tables named custtable
@CustTable	@Table CustTable	resolved to the same token
@DataModel	@DataModel:Tables	one node, narrowed to one of its types
@datamodel @tables	@DataModel:Tables	the same, written longhand

A node's own types live in its column: Data Model holds Tables, Table Extensions, Views, View Extensions, Queries, Data Entities, Maps, Table Collections and the rest; Code holds Classes, Macros and so on.

Escape peels off one layer at a time: the @ list, then the funnel, and only then the text in the box. With the box empty, Escape hands the keyboard to the tree.

Keyboard

The tree is a single tab stop and the focused row carries it, so the keyboard starts on the first row without a click.

Key	Does
↑ ↓	move down / up
→	opens a closed node, then steps onto its first child
←	closes an open node, then steps out to its parent
Home End	first / last visible row
PageUp PageDown	jump a screenful
Enter	opens the focused row — a Base Enum's values, a query's metadata, a Fields section's grid, an element's X++ source
Space	folds the focused row
letters	jumps to the next row by label prefix; the buffer resets after ~0.9 s, and the same letter cycles through matching names
Shift+F10	opens the row's context menu

To get the keyboard into the tree without a mouse: click anywhere in it, or press Escape in an empty search box.

Background loading

Opening the view starts a background warm and reports it — Reading versions…, then Warming 42/318 types…, then Ready · 318 types · 2 versions.

A type counts as warm the moment its eager head (500 rows, prefetchCount) is cached, which is what makes its foldout open instantly. So reaching the total means every foldout is already instant; the complete element lists stream in behind that and simply fill rows in. The counts are the page's own, taken from the version rows it is actually showing.

Only branches you have open are refreshed when something changes, so the background work cannot make the tree feel heavy while you are clicking in it.

Settings

Setting	Default	Meaning
d365fo.aot.ude.rootPath	%LocalAppData%\Microsoft\Dynamics365	Versions root shown as MS-UDE
d365fo.aot.rootPath	K:\AosService\PackagesLocalDirectory	Packages root shown as MS-Packages
d365fo.aot.custom.rootPath	(empty)	Array of extra roots; each is one Custom entry
d365fo.aot.modelSearchDepth	3	Levels below a version scanned for models (1–5)
d365fo.aot.defaultViewMode	models	models or classic — what a version opens as
d365fo.aot.eagerLoad	true	Prefetch element lists in the background
d365fo.aot.prefetchCount	500	Rows prefetched per type; the rest stream in
d365fo.aot.showDescriptorPath	false	Show a model's descriptor path in the row
d365fo.aot.autoResolve	false	Resolve every field when one is picked
d365fo.aot.resolve.language	en-US	Language of resolved labels and help
d365fo.aot.{ude,packages,custom}.cache.memory	true	Keep discovered models in memory
d365fo.aot.{ude,packages,custom}.cache.ttlMinutes	60	Rebuild that root this long after startup; 0 = manual only

Paths expand %NAME%, $NAME, ${NAME} and a leading ~.

Development

npm install
npm run compile       # tsc
npm run icons         # regenerate resources/icon-map.json from the icon sources
npm run package       # build the .vsix
node ./scripts/release.mjs --bump patch|minor|major

Release notes are in each commit message; AGENTS.md describes the layout and the constraints worth keeping.