Reflection Export

KDataForge can export every reflected type loaded by running game plus Blueprint-generated classes, user-defined structs, and user-defined enums found through Asset Registry. Exporter runs on game thread in bounded slices. JSON writing runs in background.

Run

Wait until world begins play, then use console:

KDF.DumpReflection

Or chat:

/kdf-reflection

The two commands do not export the same amount:

Start	Options it uses	Result
Console KDF.DumpReflection (bare)	none	Classes, structs, enums, defaults, Blueprint mappings, textures, the settings index and the cold-property catalog in the final ZIP. No functions, no data-asset or curve indexes and no flattened classes.
Chat /kdf-reflection (bare)	--assets --functions --flattened --pack --image-max-dimension=1024	The full profile: everything above plus functions, asset indexes and flattened classes.
Launch argument -KDFReflectionAutoExport=<dir>	--assets --functions --flattened (and --image-max-dimension from -KDFReflectionAutoImageMaxDimension=<n> if given)	The same export, started automatically once a world has begun play.

For the data the desktop editor needs (function completion in templates, asset-by-class indexes, inherited properties) use the bare chat command, the auto export, or give the console command the options yourself: KDF.DumpReflection --assets --functions --flattened. The chat defaults apply only when you give no option at all; as soon as you pass one, exactly the options you passed are used.

Clients do nothing unless --force is supplied. Server or host is normal export location. Default directory is FactoryGame/KMods/ReflectionExport/.

Option	Meaning
--out <dir>	Override output directory.
--mounts /Game,/Plugin	Restrict Blueprint discovery to comma-separated mount points.
--assets	Add asset-by-class indexes beyond textures; loading attempts still cover every selected registry asset.
--asset-cap N	Limit assets recorded per class.
--functions	Include reflected function signatures and flags (see Functions).
--flattened	Write inherited-property view to classes.flat.ndjson.
--image-max-dimension N	Largest exported texture side in pixels, 1 to 4096; default 1024.
--pack	Compatibility no-op; final ZIP is always written.
`—skip-widgets[=true	false]`
--widgets	Shortcut that includes widget Blueprints.
--budget-ms N	Game-thread budget per tick; default 8.
--batch-size N	Blueprint load batch size; garbage collection runs between batches.
--families name:path,...	Extend linter catalog families.
--force	Allow local client export.

Progress appears in chat and LogKDFReflection. Run KDF.ValidateReflection [--out <dir>] after completion. Validation checks required FactoryGame reflection shapes, native/Blueprint mapping, authored user-struct member names, required files, and deterministic default-value round trips.

Output

• manifest.json: runtime engine/build, platform, options, installed mods, counts, and failed loads.
• classes.ndjson, structs.ndjson, enums.ndjson: path-sorted records with inline property data.
• classes.flat.ndjson: optional inherited-property view.
• indexes/subclasses.json, indexes/assets.json: class and registry lookup indexes.
• indexes/settings.json: game settings that session:, ags: and option: references can read, see Settings index.
• catalog/cold_properties.json: the cold-property catalog, see Reload classification.
• indexes/textures.json: image path, format, dimensions, export method, or per-texture failure reason.
• images/**: selected texture images as PNG, proportionally limited to 1024x1024.
• nativeMapping.json: native-to-Blueprint and reverse mappings.
• catalog/instanced_classes.json: linter family catalog.
• schema/reflection.schema.json: draft 2020-12 schema.
• <ISO-date>.kdfdata: mandatory ZIP bundle containing every output file.

Texture selection recursively scans reflected non-widget class defaults. This retains descriptor, item, recipe, and schematic icons while excluding material-only maps, widget-only decoration, unreferenced helper textures, dynamic render/media textures, and transient runtime textures without a portable asset identity. Selected textures remain uncapped and appear in indexes/textures.json with Asset Registry tags, source and exported dimensions, resize state, image path, or explicit failure details. Every successful image is PNG. Cooked BC/BC7 data is decoded before writing; GPU readback supplies pixels when cooked CPU data is unavailable. Images larger than 1024x1024 are proportionally downscaled or use a suitable cooked mip. Smaller images keep their dimensions. Unavailable textures remain indexed but produce no placeholder image.

Exporter attempts to load every previously unloaded registry asset under configured mounts with quiet/no-warn flags and bounded batches. Failed loads remain in manifest. Garbage collection runs through engine safe points, never directly from ticker-time export code. --assets adds indexes for data assets, curves, and other classes referenced by object properties; --asset-cap applies only to non-texture index classes, not loading coverage.

Native constructors sometimes generate a fresh GUID, current timestamp, seed, transient object name, or uninitialized byte sequence. Exporter detects volatile reflected types and values, emits reflected zero value, and writes defaultVolatile: true. Result stays valid ImportText input and deterministic. Stable constructor defaults remain unchanged. Blueprint-authored member names are emitted lowercase because Unreal’s case-preserving FName display casing depends on asset load order. Lookup remains case-insensitive.

To import, open desktop editor Datapacks, choose Import game data, select generated .kdfdata, then bind imported datapack to project. Pack Manager validates manifest/schema, stores immutable archive copy, and exposes contents as datapack reflection section to editor and language server. Directory form is useful during editor/language-server development.

Functions

With --functions (included in the chat default and the auto export) each class record in classes.ndjson gets a functions array. The desktop editor uses it to complete and check template function calls.

Field	Meaning
name	The function name, lowercased so exports of different runs compare equal
authoredName	The name with its authored letter case (GetItemName). Editors show this one.
path	<ownerPath>:<name>
ownerPath	The class that declares the function
flags	The function flags, for example native, BlueprintPure, Const, Static, net and event flags
params	Input parameters as property records, in declaration order
return	The return value as a property record; absent when the function returns nothing

Property records use the same shape as class properties, including authoredName.

Settings index

indexes/settings.json lists the game settings that session:, ags: and option: references can read. It is written by every export.

Field	Meaning
schemaVersion, engineVersion	Format and build
counts	Number of settings per provider: session, ags, option, other
settings	The records, sorted by provider, lowercase id and path
unresolved	Setting assets that could not be indexed, with a reason (for example an empty id)

A record has:

Field	Meaning
id	The setting id (StrId), exactly what follows the prefix in ags:<id>
provider	session (SML session setting), ags (advanced game settings), option (local game options) or other (not readable by a prefix)
path, class, source	The asset, its class, and which mod or the base game provides it
displayName, tooltip	The texts shown in game
valueType	bool, int, float, string, color or other
default	The default value when it can be read
range, displayRange	Slider or selection bounds; displayRange only when it differs
options	{value, label} choices of an integer selector
placements	Options-menu locations. Each entry contains category, optional subcategory and row priority; categories include class, display name and menu priority.
sessionWide, dedicatedServerRelevant	Whether the setting is stored per session and whether a dedicated server uses it
managerClass, mapWhitelist	The manager that owns the setting and, for session settings, the maps it is limited to

Active runtime-generated KDataForge sound sliders are included as option records with stable virtual paths and their Options → Audio placement. Dedicated servers do not create local Audio settings, so their exports omit these runtime-only records.

The editor completes setting ids from this file and reports an unknown id as setting.unknown-id when the file exists.

Reload classification and cold-property catalog

Every property declared directly by a class carries two extra fields under its kdf object:

Field	Meaning
kdf.reload	hot, cold or newActors
kdf.reloadReason	One sentence that says why, present when the classification comes from the catalog

• hot: a write applies live (an explicit allow-list entry).
• cold: the game reads the property once or only when an object is created, so a live write does not change existing state.
• newActors: the class default belongs to an actor or component, so only newly spawned actors see a write (the patch can set applyToSpawnedActors: true to include existing actors).

Struct members, function parameters and container elements inherit the classification of the class property that contains them. The editor shows the classification next to path: completions and reports operations on cold or newActors properties as property.cold, see Pack Configuration.

catalog/cold_properties.json is the catalog behind it: version, a description, and entries of {class, property, reload, reason, verified}. A class entry includes its subclasses and the property name is case-insensitive. verified: false marks an entry that is a reasonable assumption not yet checked in game.

Editor Metadata Supplement

Packaged game may have WITH_METADATA disabled. Runtime records then contain metadataAvailable: false; export still succeeds. Generate metadata in modding editor:

UnrealEditor-Cmd.exe FactoryGame.uproject -run=KDFReflectionMetaExport -out=C:\Temp\KDFMeta

Merge supplement into separate copy with same native commandlet:

UnrealEditor-Cmd.exe FactoryGame.uproject -run=KDFReflectionMetaExport `
  -runtime=C:\Path\ReflectionExport `
  -supplement=C:\Temp\KDFMeta\metadata.supplement.json `
  -out=C:\Path\ReflectionMerged

Merge records editor and game build per field and rebuilds mandatory ISO-named .kdfdata ZIP. The -runtime and -out directories must not overlap: they cannot be equal, and neither may contain the other. The -supplement file must be outside the -out directory, especially when using -force, which replaces an existing merge output directory. These path checks also apply without -force.

On Windows and Linux, checks compare normalized paths and resolved physical paths, so symlink or junction aliases cannot bypass either restriction. Subsequent merge reads and writes use those resolved paths. The runtime directory and supplement file must exist. A new output path may have missing parent directories: the commandlet resolves its nearest existing directory ancestor and appends the missing components. Empty, inaccessible, dangling, or otherwise unresolvable paths are rejected before an existing output is deleted. Unsupported platforms reject the merge.

Before -force replaces an existing output directory, the commandlet inspects its contents without following link targets. Any nested symlink or Windows reparse point blocks replacement, even if its target is unrelated to the inputs. Unreadable entries, failed directory enumeration, or more than 1,000,000 entries also block replacement before deletion. Remove those entries or choose a new output directory, then retry.

No Python merge script is packaged into mod or archive.

For full file/schema checks and deterministic comparison of two exports:

python Mods/GameFeatures/KDataForge/Tools/validate_reflection_export.py `
  C:\Path\ReflectionExport --compare C:\Path\SecondReflectionExport

Validator applies emitted draft 2020-12 schema to every JSON record and excludes only manifest.generatedAt from comparison hash. It requires Python jsonschema.

Limits

• Blueprint load failures remain in manifest.json.failedLoads with reason.
• Dedicated-server cooks or unsupported GPU formats may expose no readable pixels. Such records contain failure details instead of image bytes.
• Per-class cap applies to non-texture classes.
• All-mount exports can be large, especially with functions, flattened records, assets, or widgets.
• Tick budget is checked between reflected records and Blueprint loads. One synchronous Asset Registry query, Blueprint load, garbage collection, or unusually large type can exceed budget by its own execution time because Unreal does not expose resumable versions of those operations.
• Output determinism assumes identical game build, mod set, options, and registered content.