Schema v3 Recipe Authoring Guide¶

This guide covers the complete JSON schema for creating custom Asset Scaffolding recipes. Schema v3 introduces powerful features like parameters, presets, conditional sections, and recipe inheritance.

Schema Overview¶

{
  "schema_version": 3,
  "id": "unique_recipe_id",
  "display_name": "Human Readable Name",
  "description": "What this recipe creates",

  // Metadata
  "author": "Your Name",
  "version": "1.0.0",
  "category": "Gameplay",
  "tags": ["blueprint", "character"],

  // Customization (Schema v3)
  "parameters": [...],
  "presets": [...],

  // Asset definition
  "asset_type": "Blueprint",
  "asset_subtype": "Character",
  "expected_path": "/Game/Blueprints/{{Name}}",

  // Blueprint contents
  "components": [...],
  "variables": [...],
  "functions": [...],
  "interfaces": [...],
  "event_graph": [...]
}

Core Fields¶

Identification¶

Field	Type	Required	Description
`schema_version`	int	Yes	Must be `3` for Schema v3
`id`	string	Yes	Unique identifier (lowercase, underscores)
`display_name`	string	Yes	Human-readable name shown in UI
`description`	string	Yes	What the recipe creates

Metadata¶

Field	Type	Required	Description
`author`	string	No	Recipe author name
`version`	string	No	Semantic version (default: "1.0.0")
`category`	string	Yes	Category for organization
`pack_id`	string	No	Recipe pack (fps_pack, rpg_pack, etc.)
`tags`	string[]	No	Searchable tags
`is_curated`	bool	No	Official BrahmaForge recipe
`is_template`	bool	No	Base recipe for inheritance only
`is_deprecated`	bool	No	Mark as deprecated

Asset Definition¶

Field	Type	Required	Description
`asset_type`	string	Yes	Blueprint, WidgetBlueprint, Material, DataAsset, etc.
`asset_subtype`	string	No	For Blueprints: Actor, Character, Pawn, etc.
`parent_class`	string	No	Parent class path for custom inheritance
`expected_path`	string	No	Suggested output path (supports `{{Param}}`)

Parameters¶

Parameters make recipes customizable. Users can adjust values when scaffolding.

Parameter Definition¶

{
  "parameters": [
    {
      "name": "CharacterName",
      "type": "string",
      "default": "MyCharacter",
      "description": "Name for the character",
      "required": true,
      "group": "Identity"
    },
    {
      "name": "MaxHealth",
      "type": "float",
      "default": "100.0",
      "min": 1,
      "max": 100000,
      "description": "Maximum health points",
      "group": "Stats"
    },
    {
      "name": "CharacterType",
      "type": "enum",
      "default": "Player",
      "options": ["Player", "NPC", "Enemy"],
      "description": "Type of character",
      "group": "Identity"
    },
    {
      "name": "CanSprint",
      "type": "bool",
      "default": "true",
      "description": "Enable sprinting",
      "group": "Abilities"
    }
  ]
}

Parameter Types¶

Type	Description	Additional Fields
`string`	Text value	`validation_regex`
`int`	Integer number	`min`, `max`
`float`	Decimal number	`min`, `max`
`bool`	true/false	-
`enum`	Selection from options	`options` (required)
`asset_ref`	Asset reference	`asset_class`

Parameter Fields¶

Field	Type	Required	Description
`name`	string	Yes	Parameter name (use in templates as `{{Name}}`)
`type`	string	Yes	One of: string, int, float, bool, enum, asset_ref
`default`	string	Yes	Default value (as string)
`description`	string	No	Shown in UI
`required`	bool	No	Must be provided (default: true)
`group`	string	No	UI grouping
`min`	number	No	Minimum value (numeric types)
`max`	number	No	Maximum value (numeric types)
`options`	string[]	Enum only	Valid enum values
`validation_regex`	string	No	Regex pattern for string validation

Presets¶

Presets are pre-configured parameter combinations for quick scaffolding.

{
  "presets": [
    {
      "name": "ThirdPerson_Player",
      "description": "Standard third-person player character",
      "values": {
        "CharacterName": "Player",
        "CharacterType": "Player",
        "MaxHealth": "100",
        "WalkSpeed": "600",
        "HasCamera": "true",
        "CameraStyle": "ThirdPerson"
      },
      "tags": ["player", "third-person"]
    },
    {
      "name": "Basic_Enemy",
      "description": "Basic enemy character",
      "values": {
        "CharacterName": "Enemy",
        "CharacterType": "Enemy",
        "MaxHealth": "50",
        "HasCamera": "false"
      },
      "tags": ["enemy", "ai", "combat"]
    }
  ]
}

Preset Fields¶

Field	Type	Required	Description
`name`	string	Yes	Preset identifier
`description`	string	No	What this preset creates
`values`	object	Yes	Parameter value overrides
`tags`	string[]	No	Searchable tags
`thumbnail_path`	string	No	Preview image path

Template Expressions¶

Use {{ParameterName}} syntax to insert parameter values anywhere in the recipe.

In Expected Path¶

{
  "expected_path": "/Game/Blueprints/Characters/BP_{{CharacterName}}"
}

In Component Properties¶

{
  "components": [
    {
      "class": "CharacterMovementComponent",
      "name": "CharacterMovement",
      "properties": {
        "MaxWalkSpeed": "{{WalkSpeed}}",
        "JumpZVelocity": "{{JumpHeight}}"
      }
    }
  ]
}

In Variable Defaults¶

{
  "variables": [
    {
      "name": "MaxHealth",
      "type": "float",
      "default": "{{MaxHealth}}"
    }
  ]
}

Enum Mapping¶

Map enum parameter values to different output values:

{
  "properties": {
    "Mobility": "{{CanMove:true=Movable,false=Static}}"
  }
}

Components¶

Define Blueprint components to add.

{
  "components": [
    {
      "class": "CapsuleComponent",
      "name": "CapsuleComponent",
      "is_root": true,
      "properties": {
        "CapsuleHalfHeight": "96",
        "CapsuleRadius": "42"
      }
    },
    {
      "class": "SkeletalMeshComponent",
      "name": "Mesh",
      "attach_to": "CapsuleComponent"
    },
    {
      "class": "SpringArmComponent",
      "name": "CameraBoom",
      "attach_to": "CapsuleComponent",
      "condition": "{{HasCamera}} == true",
      "properties": {
        "TargetArmLength": "{{CameraArmLength}}",
        "bUsePawnControlRotation": "true"
      }
    },
    {
      "class": "CameraComponent",
      "name": "FollowCamera",
      "attach_to": "CameraBoom",
      "attach_socket": "CameraSocket",
      "condition": "{{HasCamera}} == true"
    }
  ]
}

Component Fields¶

Field	Type	Required	Description
`class`	string	Yes	UE component class name
`name`	string	Yes	Instance name
`is_root`	bool	No	Set as root component
`attach_to`	string	No	Parent component name
`attach_socket`	string	No	Socket name for attachment
`properties`	object	No	Property key-value overrides
`condition`	string	No	Include only if condition is true

Conditional Components¶

Use the condition field to include components based on parameter values:

{
  "class": "AIPerceptionComponent",
  "name": "AIPerception",
  "condition": "{{UsePerception}} == true"
}

Supported operators: ==, !=, >, <, >=, <=

Combine conditions: {{A}} == true && {{B}} > 0

Variables¶

Define Blueprint variables.

{
  "variables": [
    {
      "name": "MaxHealth",
      "type": "float",
      "default": "{{MaxHealth}}",
      "category": "Stats",
      "tooltip": "Maximum health points",
      "exposed": true
    },
    {
      "name": "CurrentHealth",
      "type": "float",
      "default": "{{MaxHealth}}",
      "category": "Stats",
      "replicated": true,
      "replication_condition": "COND_OwnerOnly"
    },
    {
      "name": "InventoryItems",
      "type": "object",
      "object_class": "InventoryItem",
      "is_array": true,
      "category": "Inventory"
    },
    {
      "name": "TeamColor",
      "type": "struct",
      "struct_type": "LinearColor",
      "default": "(R=1,G=0,B=0,A=1)",
      "category": "Team"
    }
  ]
}

Variable Fields¶

Field	Type	Required	Description
`name`	string	Yes	Variable name
`type`	string	Yes	Type (see table below)
`default`	string	No	Default value
`category`	string	No	Category in Details panel
`tooltip`	string	No	Description tooltip
`exposed`	bool	No	Blueprint editable (default: true)
`read_only`	bool	No	Read-only in editor
`replicated`	bool	No	Network replicated
`replication_condition`	string	No	COND_None, COND_InitialOnly, COND_OwnerOnly
`is_array`	bool	No	Make array type
`struct_type`	string	Struct only	Struct name (Vector, LinearColor, etc.)
`object_class`	string	Object only	Object class path

Variable Types¶

Type	Description	Example Default
`bool`	Boolean	`"false"`
`int`	Integer	`"0"`
`float`	Float	`"0.0"`
`text`	FText	`"Hello"`
`string`	FString	`"World"`
`name`	FName	`"None"`
`struct`	Struct	Depends on struct_type
`object`	Object reference	`"None"`

Functions¶

Define Blueprint functions and events.

{
  "functions": [
    {
      "name": "TakeDamage",
      "is_event": true,
      "category": "Damage",
      "tooltip": "Handle incoming damage",
      "stub_implementation": "subtract_health_and_check_death",
      "inputs": [
        { "name": "DamageAmount", "type": "float" },
        { "name": "DamageEvent", "type": "struct", "struct_type": "DamageEvent" },
        { "name": "EventInstigator", "type": "object", "object_class": "Controller" }
      ],
      "outputs": [
        { "name": "ActualDamage", "type": "float" }
      ]
    },
    {
      "name": "GetHealthPercent",
      "category": "Stats",
      "is_pure": true,
      "outputs": [
        { "name": "Percent", "type": "float" }
      ]
    },
    {
      "name": "Heal",
      "category": "Stats",
      "blueprint_callable": true,
      "access_specifier": "Public",
      "inputs": [
        { "name": "HealAmount", "type": "float" }
      ]
    }
  ]
}

Function Fields¶

Field	Type	Required	Description
`name`	string	Yes	Function name
`category`	string	No	Category in Blueprint
`tooltip`	string	No	Description
`is_event`	bool	No	Is this an event (BeginPlay, Tick, etc.)
`is_pure`	bool	No	Pure function (no side effects)
`blueprint_callable`	bool	No	Callable from Blueprint (default: true)
`access_specifier`	string	No	Public, Protected, Private
`stub_implementation`	string	No	Implementation hint
`inputs`	array	No	Input parameters
`outputs`	array	No	Output parameters

Interfaces¶

Implement Blueprint interfaces.

{
  "interfaces": [
    {
      "path": "/Script/Engine.GenericTeamAgentInterface"
    },
    {
      "path": "/Game/Interfaces/BPI_Interactable",
      "functions_to_implement": ["OnInteract", "GetInteractionText"]
    }
  ]
}

Event Graph¶

Define starter event graph nodes.

{
  "event_graph": [
    {
      "event": "BeginPlay",
      "nodes": ["InitializeHealth", "SetupMovement"],
      "comment": "Character initialization"
    },
    {
      "event": "SetupPlayerInputComponent",
      "nodes": ["BindMoveActions", "BindJumpAction"],
      "comment": "Input binding"
    }
  ]
}

For WidgetBlueprint recipes, use root_widget to define the widget hierarchy.

{
  "asset_type": "WidgetBlueprint",
  "expected_path": "/Game/UI/WBP_{{HUDName}}",

  "root_widget": {
    "name": "RootCanvas",
    "class": "CanvasPanel",
    "children": [
      {
        "name": "HealthContainer",
        "class": "HorizontalBox",
        "children": [
          {
            "name": "HealthBar",
            "class": "ProgressBar",
            "is_variable": true,
            "style": {
              "min_width": 200,
              "min_height": 20,
              "background_color": [0.1, 0.1, 0.1, 0.85]
            }
          },
          {
            "name": "HealthText",
            "class": "TextBlock",
            "default_text": "100/100",
            "is_variable": true
          }
        ]
      }
    ]
  }
}

Common widget classes: - CanvasPanel - Root canvas - VerticalBox - Vertical layout - HorizontalBox - Horizontal layout - Border - Background/border container - Button - Clickable button - TextBlock - Text display - Image - Image display - ProgressBar - Progress indicator - Spacer - Layout spacer

{
  "style": {
    "background_color": [0.1, 0.1, 0.1, 0.85],
    "hover_color": [0.18, 0.18, 0.18, 0.9],
    "pressed_color": [0.08, 0.08, 0.08, 0.9],
    "text_color": [1, 1, 1, 1],
    "font_size": 16,
    "text_justification": "Center",
    "padding": 4,
    "min_width": 100,
    "min_height": 40
  }
}

Recipe Inheritance¶

Extend existing recipes with extends_recipe.

{
  "schema_version": 3,
  "id": "fps_character",
  "display_name": "FPS Character",
  "extends_recipe": "character_blueprint",

  "parameters": [
    {
      "name": "HasWeapon",
      "type": "bool",
      "default": "true",
      "group": "Combat"
    }
  ],

  "components": [
    {
      "class": "SkeletalMeshComponent",
      "name": "ArmsMesh",
      "attach_to": "FollowCamera"
    }
  ]
}

Inherited recipes: - Merge parameters (child overrides parent) - Merge components (child adds to parent) - Merge variables and functions - Override metadata

Dependencies¶

Declare required plugins or classes.

{
  "dependencies": [
    {
      "type": "plugin",
      "name": "EnhancedInput",
      "optional": false
    },
    {
      "type": "class",
      "name": "/Script/AIModule.AIController"
    },
    {
      "type": "recipe",
      "name": "blackboard_data",
      "optional": true
    }
  ]
}

Conditions¶

Platform or configuration-based inclusion.

{
  "conditions": [
    {
      "type": "plugin",
      "key": "EnhancedInput",
      "value": "enabled"
    },
    {
      "type": "platform",
      "key": "Windows",
      "value": "true"
    }
  ]
}

Complete Example¶

Here's a complete character recipe demonstrating all Schema v3 features:

{
  "schema_version": 3,
  "id": "my_character",
  "display_name": "My Custom Character",
  "description": "A fully customizable character blueprint",
  "author": "Your Name",
  "version": "1.0.0",
  "category": "Gameplay",
  "tags": ["character", "player", "custom"],

  "parameters": [
    {
      "name": "Name",
      "type": "string",
      "default": "Player",
      "required": true,
      "group": "Identity"
    },
    {
      "name": "Health",
      "type": "float",
      "default": "100",
      "min": 1,
      "max": 10000,
      "group": "Stats"
    },
    {
      "name": "HasCamera",
      "type": "bool",
      "default": "true",
      "group": "Features"
    }
  ],

  "presets": [
    {
      "name": "Default_Player",
      "description": "Standard player",
      "values": {
        "Name": "Player",
        "Health": "100",
        "HasCamera": "true"
      }
    }
  ],

  "asset_type": "Blueprint",
  "asset_subtype": "Character",
  "expected_path": "/Game/Characters/BP_{{Name}}",

  "components": [
    {
      "class": "CapsuleComponent",
      "name": "Capsule",
      "is_root": true
    },
    {
      "class": "CameraComponent",
      "name": "Camera",
      "attach_to": "Capsule",
      "condition": "{{HasCamera}} == true"
    }
  ],

  "variables": [
    {
      "name": "MaxHealth",
      "type": "float",
      "default": "{{Health}}",
      "exposed": true
    }
  ],

  "functions": [
    {
      "name": "TakeDamage",
      "is_event": true,
      "inputs": [
        { "name": "Amount", "type": "float" }
      ]
    }
  ]
}

Best Practices¶

Use Descriptive IDs: fps_character not char1
Group Parameters: Use the group field for UI organization
Provide Presets: Give users quick-start options
Document Everything: Use description and tooltip fields
Test Conditions: Verify conditional components work correctly
Version Your Recipes: Update version when making changes
Use Tags: Make recipes discoverable with relevant tags

Validation¶

Use Studio Mode to validate recipes before use: - Schema version check - Required field validation - Parameter type checking - Component class verification - Condition syntax validation