PCG Tools

PCG tools operate on UE PCG graph assets. PCG has three important surfaces: graph structure, node settings, and graph user parameters. Keep those separate.

Recommended Flow

1. Inspect the graph with pcg_graph_inspect.
2. Use pcg_palette before adding a node.
3. Use schema_inspect before pcg_graph_edit commands.
4. Use pcg_node_inspect before editing node settings.
5. Use pcg_parameter_inspect before editing graph parameters.
6. Run pcg_compile after meaningful changes.

Tool Summary

Tool	Purpose
pcg_graph_inspect	Inspect graph nodes, pins, links, and defaults.
pcg_palette	Search UE PCG palette actions for node creation.
pcg_node_inspect	Inspect one PCG node instance or settings class.
pcg_parameter_inspect	Inspect graph user parameters.
pcg_parameter_edit	Edit graph user parameters.
pcg_graph_edit	Apply explicit PCG graph edit commands.
pcg_graph_layout	Format selected PCG graph nodes.
pcg_compile	Validate and compile-confirm a PCG graph.

pcg_graph_inspect

Parameters

Field	Required	Notes
assetPath	yes	PCG graph asset path.
graph	no	Optional PCG graph reference.
view	no	overview, pins, links, defaults, or full; defaults to overview.
filter.nodeIds	no	Restrict to node ids.
filter.text	no	Case-insensitive fuzzy search over node id, title, class, and compact JSON.
page.limit	no	Defaults to 50, maximum 1000.
page.cursor	no	Pagination cursor.

Use overview first. Move to pins, links, or defaults only when planning connections or defaults.

Readback Limits

pcg_graph_inspect is the first stop for topology, pins, links, defaults, and known effectiveSettings. It is not a guaranteed full Details-panel export for every PCG settings object.

For ordinary node inspection, stay inside pcg_graph_inspect and pcg_node_inspect when the needed value appears in pins, defaults, or effectiveSettings. If a task depends on exact instance-level settings that are not surfaced yet, inspect the live settings object with execute and cite that fallback explicitly.

Spawn Actor is a common fallback-prone case. Template actor/class identity, spawn options, data-layer settings, HLOD settings, and spawned actor property override mappings may require direct settings-object inspection until the PCG full-coverage readback work lands. Do not infer property override mappings from topology alone.

Selector Readback

Selector-backed settings follow UE’s FPCGAttributePropertySelector parsing. Compact strings are accepted for edits, but inspect output should be read from the structured selector fields. For example, Position.Z is read back as an attribute selector with name: "Position" and accessors: ["Z"]; $Position is the property-selector form.

For Filter By Attribute, verify value filters through effectiveSettings.targetAttribute. It includes text, selection, name, domain, attributeOrProperty, accessors, accessorPath, kind, and valid so agents can distinguish full-vector targets from component targets such as Position.Z.

Use pcg_node_inspect for detailed selector property discovery. Selector-backed settings include valueKind: "pcgSelector" and accept both compact UE strings and structured selector objects in pcg_graph_edit setPinDefault or setProperty.

pcg_palette

Parameters

Field	Required	Notes
assetPath	no	PCG graph asset path.
graph	no	Optional graph reference.
query	no	Fuzzy search over UE palette label, category, tooltip, keywords, and payload.
elementTypes	no	native, blueprint, subgraph, settings, asset, dataAsset, or other.
limit	no	Defaults to 50, maximum 500.
offset	no	Paging offset.

Pass the selected palette entry to pcg_graph_edit rather than guessing settings classes.

pcg_graph_edit

Parameters

Field	Required	Notes
assetPath	yes	PCG graph asset path.
graph	no	Optional graph reference.
commands	yes	Ordered command envelopes with kind.
dryRun	no	Validate without applying.
returnDiff	no	Include diff when supported.
returnDiagnostics	no	Defaults to true.
expectedRevision	no	Optimistic mutation guard when supported.

Command-specific fields are intentionally omitted from tools/list. Call schema_inspect with domain: pcg, tool: pcg_graph_edit, and the selected operation.

pcg_node_inspect

Parameters

Field	Required	Notes
assetPath	no	Required for instance mode.
graph	no	Optional graph reference.
node.id	no	PCG node id for instance mode.
nodeClass	no	PCG settings class path for class mode.
settingsClass	no	Alias for nodeClass.

Use this before editing node settings or when you need to understand a settings class returned by the palette.

pcg_parameter_inspect

Parameters

Field	Required	Notes
assetPath	no	PCG graph asset path.
graph	no	Optional graph reference.
name	no	Exact parameter name filter.

PCG graph parameters are graph-owned user parameters, not graph nodes.

pcg_parameter_edit

Parameters

Field	Required	Notes
assetPath	yes	PCG graph asset path.
graph	no	Optional graph reference.
operation	yes	create, update, rename, delete, or setDefault.
args	yes	Operation-specific arguments from schema_inspect.
dryRun	no	Validate without applying.
returnDiff	no	Include diff when supported.
returnDiagnostics	no	Defaults to true.
expectedRevision	no	Optimistic mutation guard when supported.

Call schema_inspect with domain: pcg, tool: pcg_parameter_edit, and the selected operation before editing.

pcg_graph_layout

Parameters

Field	Required	Notes
assetPath	yes	PCG graph asset path.
graph	no	Optional graph reference.
scope	yes	Explicit node selection to format.
spacing	no	Layout spacing.
origin	no	Optional top-left layout anchor.

Layout changes positions only; it does not change PCG behavior.

pcg_compile

Parameters

Field	Required	Notes
assetPath	yes	PCG graph asset path.
graph	no	Optional graph reference.

Use compile after graph, node setting, or parameter changes.