Add option to make LWJGL graphics APIs runtime only.

src/main/java/net/fabricmc/loom/api/LoomGradleExtensionAPI.java

@@ -291,6 +291,11 @@ default void splitMinecraftJar() {
 
 	Property<Boolean> getRuntimeOnlyLog4j();
 
+	/**
+	 * When enabled, lwjgl-opengl or lwjgl-vulkan will be added as a runtime dependency preventing the mod from compiling against a specific graphics API.
+	 */
+	Property<Boolean> getRuntimeOnlyLwjglGraphics();
+
 	Property<Boolean> getSplitModDependencies();
 
 	<T extends RemapperParameters> void addRemapperExtension(Class<? extends RemapperExtension<T>> remapperExtensionClass, Class<T> parametersClass, Action<T> parameterAction);

src/main/java/net/fabricmc/loom/configuration/providers/minecraft/MinecraftLibraryProvider.java

@@ -44,6 +44,7 @@
 import net.fabricmc.loom.configuration.providers.minecraft.library.LibraryProcessorManager;
 import net.fabricmc.loom.configuration.providers.minecraft.library.MinecraftLibraryHelper;
 import net.fabricmc.loom.configuration.providers.minecraft.library.processors.RuntimeLog4jLibraryProcessor;
+import net.fabricmc.loom.configuration.providers.minecraft.library.processors.RuntimeLwjglGraphicsLibraryProcessor;
 import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.Platform;
 import net.fabricmc.loom.util.gradle.GradleUtils;
@@ -70,6 +71,10 @@ private List<String> getEnabledProcessors() {
 			enabledProcessors.add(RuntimeLog4jLibraryProcessor.class.getSimpleName());
 		}
 
+		if (extension.getRuntimeOnlyLwjglGraphics().get()) {
+			enabledProcessors.add(RuntimeLwjglGraphicsLibraryProcessor.class.getSimpleName());
+		}
+
 		final Provider<String> libraryProcessorsProperty = project.getProviders().gradleProperty(Constants.Properties.LIBRARY_PROCESSORS);
 
 		if (libraryProcessorsProperty.isPresent()) {

src/main/java/net/fabricmc/loom/configuration/providers/minecraft/library/processors/RuntimeLwjglGraphicsLibraryProcessor.java

@@ -0,0 +1,59 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2026 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.configuration.providers.minecraft.library.processors;
+
+import java.util.function.Consumer;
+import java.util.function.Predicate;
+
+import net.fabricmc.loom.configuration.providers.minecraft.library.Library;
+import net.fabricmc.loom.configuration.providers.minecraft.library.LibraryContext;
+import net.fabricmc.loom.configuration.providers.minecraft.library.LibraryProcessor;
+import net.fabricmc.loom.util.Platform;
+
+public class RuntimeLwjglGraphicsLibraryProcessor extends LibraryProcessor {
+	private static final String LWJGL_OPENGL = "org.lwjgl:lwjgl-opengl";
+	private static final String LWJGL_VULKAN = "org.lwjgl:lwjgl-vulkan";
+
+	public RuntimeLwjglGraphicsLibraryProcessor(Platform platform, LibraryContext context) {
+		super(platform, context);
+	}
+
+	@Override
+	public ApplicationResult getApplicationResult() {
+		return ApplicationResult.CAN_APPLY;
+	}
+
+	@Override
+	public Predicate<Library> apply(Consumer<Library> dependencyConsumer) {
+		return library -> {
+			if (library.is(LWJGL_OPENGL) || library.is(LWJGL_VULKAN)) {
+				dependencyConsumer.accept(library.withTarget(Library.Target.RUNTIME));
+				return false;
+			}
+
+			return true;
+		};
+	}
+}

src/main/java/net/fabricmc/loom/extension/LoomGradleExtensionApiImpl.java

@@ -101,6 +101,7 @@ public abstract class LoomGradleExtensionApiImpl implements LoomGradleExtensionA
 	private final Property<String> defaultMixinRemapType;
 	private final Property<Boolean> remapJsrAnnotationsToJetBrains;
 	private final Property<Boolean> runtimeOnlyLog4j;
+	private final Property<Boolean> runtimeOnlyLwjglGraphics;
 	private final Property<Boolean> splitModDependencies;
 	private final Property<MinecraftJarConfiguration<?, ?, ?>> minecraftJarConfiguration;
 	private final Property<Boolean> splitEnvironmentalSourceSet;
@@ -197,6 +198,9 @@ protected LoomGradleExtensionApiImpl(Project project, LoomFiles directories) {
 		this.runtimeOnlyLog4j = project.getObjects().property(Boolean.class).convention(false);
 		this.runtimeOnlyLog4j.finalizeValueOnRead();
 
+		this.runtimeOnlyLwjglGraphics = project.getObjects().property(Boolean.class).convention(false);
+		this.runtimeOnlyLwjglGraphics.finalizeValueOnRead();
+
 		this.splitModDependencies = project.getObjects().property(Boolean.class).convention(true);
 		this.splitModDependencies.finalizeValueOnRead();
 
@@ -440,6 +444,11 @@ public Property<Boolean> getRuntimeOnlyLog4j() {
 		return runtimeOnlyLog4j;
 	}
 
+	@Override
+	public Property<Boolean> getRuntimeOnlyLwjglGraphics() {
+		return runtimeOnlyLwjglGraphics;
+	}
+
 	@Override
 	public Property<Boolean> getSplitModDependencies() {
 		return splitModDependencies;

src/test/groovy/net/fabricmc/loom/test/unit/library/processors/RuntimeLwjglGraphicsLibraryProcessorTest.groovy

@@ -0,0 +1,45 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2026 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.test.unit.library.processors
+
+import net.fabricmc.loom.configuration.providers.minecraft.library.Library
+import net.fabricmc.loom.configuration.providers.minecraft.library.LibraryProcessor
+import net.fabricmc.loom.configuration.providers.minecraft.library.processors.RuntimeLwjglGraphicsLibraryProcessor
+import net.fabricmc.loom.test.util.PlatformTestUtils
+
+class RuntimeLwjglGraphicsLibraryProcessorTest extends LibraryProcessorTest {
+	def "Make lwjgl-opengl runtime"() {
+		when:
+		def (original, context) = getLibs("26.1-snapshot-10", PlatformTestUtils.MAC_OS_X64)
+		def processor = new RuntimeLwjglGraphicsLibraryProcessor(PlatformTestUtils.MAC_OS_X64, context)
+		def processed = mockLibraryProcessorManager().processLibraries([processor], original)
+
+		then:
+		processor.applicationResult == LibraryProcessor.ApplicationResult.CAN_APPLY
+
+		findLibrary("org.lwjgl:lwjgl-opengl", original).target() == Library.Target.COMPILE
+		findLibrary("org.lwjgl:lwjgl-opengl", processed).target() == Library.Target.RUNTIME
+	}
+}