Project Settings

All settings live under Edit → Project Settings → Plugins → Unreal React Bridge. They are stored in Config/DefaultEngine.ini under [/Script/UnrealReactBridge.UnrealReactBridgeSettings].

Source: SampleProject/Plugins/UnrealReactBridge/Source/UnrealReactBridge/Public/UnrealReactBridgeSettings.h

Setting	Type	Default	Category	What it does
Default Dev URL	FString	http://localhost:3000	Connection	Fallback URL used when a ReactWebBrowser's URL property is left empty. Applied when the browser builds, so it reaches every instance that didn't set one.
Debug Mode	bool	false	Debug	Verbose Output Log tracing of every bridge event, error, and registration.
Max Event Queue Size	int32 (10–1000)	100	Advanced	How many UE → React events to buffer while React isn't ready yet. Excess events fire EBridgeErrorType::EventQueueFull.
Force Background Transparent	bool	true	Connection	Inject the html,body { background: transparent !important } CSS after each page load. Disable while developing if you want to see the page's natural background.

TIP

Debug Mode is the first thing to flip when something looks off — see /guide/debugging.

Reading settings at runtime (C++)

const UUnrealReactBridgeSettings* S = GetDefault<UUnrealReactBridgeSettings>();
const FString DevURL = S->DefaultDevURL;
const int32   Cap    = S->MaxEventQueueSize;

You can also call the static accessor:

const UUnrealReactBridgeSettings* S = UUnrealReactBridgeSettings::Get();

Overriding per build

• Set per-platform values in Config/Platform/<Platform>/PlatformEngine.ini.
• Common pattern: DefaultDevURL = http://localhost:5173 in DefaultEngine.ini for dev, override to your CDN URL in Config/DefaultEngine.ini (or a platform override) for shipping.

; Config/DefaultEngine.ini
[/Script/UnrealReactBridge.UnrealReactBridgeSettings]
DefaultDevURL=http://localhost:5173
bDebugMode=False
MaxEventQueueSize=100
bForceBackgroundTransparent=True

TIP

The fallback only fires for a browser whose URL is blank. LoadReactURL always navigates to exactly what you pass it.

See also

• /guide/production — packaging your React build and pointing the plugin at it.