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System Component

Template name: SystemComponent CLI: --template system_component Suffix: SystemComponent – produces ${Name}SystemComponent

An engine-level system component that lives on the system entity. System components provide global services that run outside of entity context – input managers, network systems, resource registries, and similar singletons. Optionally generates an EBus interface header and an EditorComponent wrapper, the same as Basic Component.

Files generated:

File	Conditional
`Source/${Name}SystemComponent.cpp`	Always
`Source/${Name}SystemComponent.h`	Always
`Include/${GemName}/${Name}Interface.h`	Only when `add_bus_interface` is true
`Source/Tools/Editor${Name}SystemComponent.h`	Only when `include_editor` is true
`Source/Tools/Editor${Name}SystemComponent.cpp`	Only when `include_editor` is true

The interface header carries cleanup_hint: "interface" – if not requested, all EBus wiring is removed from remaining files. The editor files carry cleanup_hint: "editor" – if excluded, their #include lines are stripped from siblings.

Input variables:

Var Name	Type	Default	show_if	Description
`add_bus_interface`	toggle	`true`	–	Create the Interface Bus header file
`include_editor`	toggle	`false`	`hasEditor`	Generate an EditorComponent wrapper that appears in the Editor Inspector and exports the runtime component at game-mode; only shown when the gem has an Editor module

Commands:

Command	Condition	Description
`register_file_list`	Always	Adds runtime `.h`/`.cpp` to CMake
`register_module_descriptor`	Always	Registers the component in the runtime module
`register_system_component` (`module_kind: "runtime"`)	Always	Adds to `GetRequiredSystemComponents()` in the runtime module
`register_system_component` (`module_kind: "editor"`)	Always	Adds to `GetRequiredSystemComponents()` in the editor module
`register_interface_header`	`add_bus_interface`	Registers the interface header in the API/INTERFACE target
`register_file_list`	`include_editor`	Adds editor `.h`/`.cpp` to CMake
`register_module_descriptor` (`module_kind: "editor"`)	`include_editor`	Registers the EditorComponent in the editor module
`replace_text`	`include_editor`	Strips the `"Game"` add-component-menu category from the runtime `.cpp` so only the EditorComponent appears in the editor’s Add Component menu

Notable features: The only template that registers register_system_component twice, unconditionally. The system component is added to GetRequiredSystemComponents() in both the runtime and editor modules, regardless of whether include_editor generates a separate EditorComponent file. This is distinct from Data Asset, which duplicates register_system_component for the same reason but on a dedicated DataAssetSystemComponent, not the primary generated class.

Full Template JSON

{
    "template_name": "SystemComponent",
    "origin": "Open 3D Engine - o3de.org",
    "origin_url": "https://github.com/o3de/o3de",
    "license": "Apache-2.0 or MIT",
    "license_url": "https://github.com/o3de/o3de/blob/development/LICENSE.txt",
    "display_name": "Default System Component Template",
    "summary": "A component template for a typical system component.",
    "canonical_tags": [
        "Template"
    ],
    "user_tags": [
        "SystemComponent"
    ],
    "icon_path": "preview.png",
    "copyFiles": [
        {
            "file": "Source/${Name}SystemComponent.cpp",
            "isTemplated": true
        },
        {
            "file": "Source/${Name}SystemComponent.h",
            "isTemplated": true
        },
        {
            "file": "Include/${GemName}/${Name}Interface.h",
            "isTemplated": true,
            "isInterface": true,
            "cleanup_hint": "interface",
            "condition": "add_bus_interface"
        },
        {
            "file": "Source/Tools/Editor${Name}SystemComponent.h",
            "isTemplated": true,
            "isEditor": true,
            "cleanup_hint": "editor",
            "condition": "include_editor"
        },
        {
            "file": "Source/Tools/Editor${Name}SystemComponent.cpp",
            "isTemplated": true,
            "isEditor": true,
            "cleanup_hint": "editor",
            "condition": "include_editor"
        }
    ],
    "createDirectories": [
        {
            "dir": "Include/${GemName}"
        },
        {
            "dir": "Source"
        }
    ],
    "class_wizard": {
        "display_name": "System Component",
        "class_name": "system_component",
        "description": "A system component registered in both runtime and editor modules",
        "component_suffix": "SystemComponent",

        "input_vars": [
            {
                "input_type": "toggle",
                "var_name": "add_bus_interface",
                "title": "Add Bus Interface",
                "default_value": true,
                "description": "Create the Interface Bus header file"
            },
            {
                "input_type": "toggle",
                "var_name": "include_editor",
                "title": "Add Editor Comp.",
                "default_value": false,
                "description": "Generate an EditorComponent wrapper that appears in the Editor Inspector and exports the runtime component at game-mode",
                "show_if": "hasEditor"
            }
        ],

        "process_commands": [
            {
                "command": "register_file_list",
                "args": { "component_name": "${Name}${ComponentSuffix}" }
            },
            {
                "command": "register_module_descriptor",
                "args": { "component_name": "${Name}${ComponentSuffix}", "module_kind": "runtime" }
            },
            {
                "command": "register_system_component",
                "args": { "component_name": "${Name}${ComponentSuffix}", "module_kind": "runtime" }
            },
            {
                "command": "register_system_component",
                "args": { "component_name": "${Name}${ComponentSuffix}", "module_kind": "editor" }
            },
            {
                "command": "register_interface_header",
                "condition": "add_bus_interface",
                "args": { "component_name": "${Name}" }
            },
            {
                "command": "register_file_list",
                "condition": "include_editor",
                "args": { "component_name": "Editor${Name}${ComponentSuffix}" }
            },
            {
                "command": "register_module_descriptor",
                "condition": "include_editor",
                "args": { "component_name": "Editor${Name}${ComponentSuffix}", "module_kind": "editor" }
            },
            {
                "command": "replace_text",
                "condition": "include_editor",
                "args": {
                    "component_name": "${Name}${ComponentSuffix}.cpp",
                    "text_to_replace": "AppearsInAddComponentMenu, AZ_CRC_CE(\"Game\"))",
                    "replacement": "AppearsInAddComponentMenu, AZ_CRC_CE(\"\"))"
                }
            }
        ]
    }
}

Design Notes

Same mechanic as Basic Component and Level Component. Both the runtime and Editor files start out with AppearsInAddComponentMenu(AZ_CRC_CE("Game")), the same category as Basic Component rather than something System-specific. This is the command that makes either one appear in the Game Add Component menu. If you have an Editor component, it needs to be the one available in the menu, not the base component. Turning on include_editor also runs the replace_text command that clears the runtime file’s category to AZ_CRC_CE(""), leaving the generated Editor variant as the one that shows up.

Unlike the other three, this template also calls register_system_component unconditionally, twice, regardless of include_editor. See Architecture > Commands Are Additive, Not Destructive for why that’s safe to run against an existing module.