diff --git a/src/main/java/net/neoforged/moddevgradle/dsl/RunModel.java b/src/main/java/net/neoforged/moddevgradle/dsl/RunModel.java
index 4da9e5e..9bf0637 100644
--- a/src/main/java/net/neoforged/moddevgradle/dsl/RunModel.java
+++ b/src/main/java/net/neoforged/moddevgradle/dsl/RunModel.java
@@ -156,8 +156,21 @@ public void client() {
         getType().set("client");
     }
 
+    /**
+     * Equivalent to setting {@code type = "clientData"}.
+     *
+     * <p>Should only be used for Minecraft versions starting from 1.21.4.
+     * (The first snapshot that supports this is 24w45a).
+     */
+    public void clientData() {
+        getType().set("clientData");
+    }
+
     /**
      * Equivalent to setting {@code type = "data"}.
+     *
+     * <p>Should only be used for Minecraft versions up to 1.21.3 included.
+     * (The last snapshot that supports this is 24w44a).
      */
     public void data() {
         getType().set("data");
@@ -170,6 +183,16 @@ public void server() {
         getType().set("server");
     }
 
+    /**
+     * Equivalent to setting {@code type = "serverData"}.
+     *
+     * <p>Should only be used for Minecraft versions starting from 1.21.4.
+     * (The first snapshot that supports this is 24w45a).
+     */
+    public void serverData() {
+        getType().set("serverData");
+    }
+
     /**
      * Equivalent to setting {@code ideName = ""}
      */
diff --git a/src/main/java/net/neoforged/moddevgradle/internal/ModDevPlugin.java b/src/main/java/net/neoforged/moddevgradle/internal/ModDevPlugin.java
index 726491e..1231903 100644
--- a/src/main/java/net/neoforged/moddevgradle/internal/ModDevPlugin.java
+++ b/src/main/java/net/neoforged/moddevgradle/internal/ModDevPlugin.java
@@ -309,7 +309,8 @@ public void apply(Project project) {
                 userDevConfigOnly,
                 modulePath -> modulePath.getDependencies().addLater(modulePathDependency),
                 legacyClassPath -> legacyClassPath.extendsFrom(additionalClasspath),
-                downloadAssets.flatMap(DownloadAssets::getAssetPropertiesFile)
+                downloadAssets.flatMap(DownloadAssets::getAssetPropertiesFile),
+                extension.getNeoFormVersion()
         );
 
         setupJarJar(project);
@@ -478,7 +479,8 @@ static void setupRuns(Project project,
                           Object runTemplatesSourceFile,
                           Consumer<Configuration> configureModulePath,
                           Consumer<Configuration> configureLegacyClasspath,
-                          Provider<RegularFile> assetPropertiesFile
+                          Provider<RegularFile> assetPropertiesFile,
+                          Provider<String> neoFormVersion
     ) {
         var ideIntegration = IdeIntegration.of(project, branding);
 
@@ -499,7 +501,8 @@ static void setupRuns(Project project,
                     configureModulePath,
                     configureLegacyClasspath,
                     assetPropertiesFile,
-                    devLaunchConfig
+                    devLaunchConfig,
+                    neoFormVersion
             );
             prepareRunTasks.put(run, prepareRunTask);
         });
@@ -521,7 +524,8 @@ private static TaskProvider<PrepareRun> setupRunInGradle(
             Consumer<Configuration> configureModulePath,
             Consumer<Configuration> configureLegacyClasspath, // TODO: can be removed in favor of directly passing a configuration for the moddev libraries
             Provider<RegularFile> assetPropertiesFile,
-            Configuration devLaunchConfig
+            Configuration devLaunchConfig,
+            Provider<String> neoFormVersion
     ) {
         var ideIntegration = IdeIntegration.of(project, branding);
         var configurations = project.getConfigurations();
@@ -553,7 +557,7 @@ private static TaskProvider<PrepareRun> setupRunInGradle(
             spec.shouldResolveConsistentlyWith(runtimeClasspathConfig.get());
             spec.attributes(attributes -> {
                 attributes.attributeProvider(MinecraftDistribution.ATTRIBUTE, type.map(t -> {
-                    var name = t.equals("client") || t.equals("data") ? MinecraftDistribution.CLIENT : MinecraftDistribution.SERVER;
+                    var name = t.equals("client") || t.equals("data") || t.equals("clientData") ? MinecraftDistribution.CLIENT : MinecraftDistribution.SERVER;
                     return project.getObjects().named(MinecraftDistribution.class, name);
                 }));
                 setNamedAttribute(project, attributes, Usage.USAGE_ATTRIBUTE, Usage.JAVA_RUNTIME);
@@ -590,6 +594,7 @@ private static TaskProvider<PrepareRun> setupRunInGradle(
             task.getProgramArguments().set(run.getProgramArguments());
             task.getJvmArguments().set(run.getJvmArguments());
             task.getGameLogLevel().set(run.getLogLevel());
+            task.getNeoFormVersion().set(neoFormVersion);
         });
         ideIntegration.runTaskOnProjectSync(prepareRunTask);
 
diff --git a/src/main/java/net/neoforged/moddevgradle/internal/NeoDevFacade.java b/src/main/java/net/neoforged/moddevgradle/internal/NeoDevFacade.java
index 2ba0df8..997f95f 100644
--- a/src/main/java/net/neoforged/moddevgradle/internal/NeoDevFacade.java
+++ b/src/main/java/net/neoforged/moddevgradle/internal/NeoDevFacade.java
@@ -42,7 +42,30 @@ public static void setupRuns(Project project,
                 runTemplatesSourceFile,
                 configureModulePath,
                 configureAdditionalClasspath,
-                assetPropertiesFile
+                assetPropertiesFile,
+                project.getObjects().property(String.class) // empty provider
+        );
+    }
+
+    public static void setupRuns(Project project,
+                                 Provider<Directory> argFileDir,
+                                 DomainObjectCollection<RunModel> runs,
+                                 Object runTemplatesSourceFile,
+                                 Consumer<Configuration> configureModulePath,
+                                 Consumer<Configuration> configureAdditionalClasspath,
+                                 Provider<RegularFile> assetPropertiesFile,
+                                 Provider<String> neoFormVersion
+    ) {
+        ModDevPlugin.setupRuns(
+                project,
+                Branding.NEODEV,
+                argFileDir,
+                runs,
+                runTemplatesSourceFile,
+                configureModulePath,
+                configureAdditionalClasspath,
+                assetPropertiesFile,
+                neoFormVersion
         );
     }
 
diff --git a/src/main/java/net/neoforged/moddevgradle/internal/PrepareRunOrTest.java b/src/main/java/net/neoforged/moddevgradle/internal/PrepareRunOrTest.java
index b865685..759144a 100644
--- a/src/main/java/net/neoforged/moddevgradle/internal/PrepareRunOrTest.java
+++ b/src/main/java/net/neoforged/moddevgradle/internal/PrepareRunOrTest.java
@@ -3,6 +3,7 @@
 import net.neoforged.moddevgradle.internal.utils.FileUtils;
 import net.neoforged.moddevgradle.internal.utils.OperatingSystem;
 import net.neoforged.moddevgradle.internal.utils.StringUtils;
+import net.neoforged.moddevgradle.internal.utils.VersionUtils;
 import org.gradle.api.DefaultTask;
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.DirectoryProperty;
@@ -28,6 +29,7 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.util.ArrayList;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -91,6 +93,14 @@ abstract class PrepareRunOrTest extends DefaultTask {
     @Input
     public abstract Property<Level> getGameLogLevel();
 
+    /**
+     * Only used when {@link #getRunTypeTemplatesSource()} is empty,
+     * to know whether the associated Minecraft version requires one or two data runs.
+     */
+    @Optional
+    @Input
+    public abstract Property<String> getNeoFormVersion();
+
     private final ProgramArgsFormat programArgsFormat;
 
     protected PrepareRunOrTest(ProgramArgsFormat programArgsFormat) {
@@ -147,17 +157,32 @@ private UserDevConfig getSimulatedUserDevConfigForVanilla() {
         var clientArgs = List.of("--gameDir", ".", "--assetIndex", "{asset_index}", "--assetsDir", "{assets_root}", "--accessToken", "NotValid", "--version", "ModDevGradle");
         var commonArgs = List.<String>of();
 
-        return new UserDevConfig("", "", "", List.of(), List.of(), Map.of(
-                "client", new UserDevRunType(
-                        true, "net.minecraft.client.main.Main", clientArgs, List.of(), true, false, false, false, Map.of(), Map.of()
-                ),
-                "server", new UserDevRunType(
-                        true, "net.minecraft.server.Main", commonArgs, List.of(), false, true, false, false, Map.of(), Map.of()
-                ),
-                "data", new UserDevRunType(
-                        true, "net.minecraft.data.Main", commonArgs, List.of(), false, false, true, false, Map.of(), Map.of()
-                )
+        var runTypes = new LinkedHashMap<String, UserDevRunType>();
+        runTypes.put("client", new UserDevRunType(
+                true, "net.minecraft.client.main.Main", clientArgs, List.of(), Map.of(), Map.of()
         ));
+        runTypes.put("server", new UserDevRunType(
+                true, "net.minecraft.server.Main", commonArgs, List.of(), Map.of(), Map.of()
+        ));
+
+        var splitData = getNeoFormVersion()
+                .map(VersionUtils::hasSplitDataRuns)
+                .orElse(false) // Default to single run for backwards compatibility
+                .get();
+        if (splitData) {
+            runTypes.put("clientData", new UserDevRunType(
+                    true, "net.minecraft.client.data.Main", commonArgs, List.of(), Map.of(), Map.of()
+            ));
+            runTypes.put("serverData", new UserDevRunType(
+                    true, "net.minecraft.data.Main", commonArgs, List.of(), Map.of(), Map.of()
+            ));
+        } else {
+            runTypes.put("data", new UserDevRunType(
+                    true, "net.minecraft.data.Main", commonArgs, List.of(), Map.of(), Map.of()
+            ));
+        }
+
+        return new UserDevConfig(runTypes);
     }
 
     private void writeJvmArguments(UserDevRunType runConfig) throws IOException {
diff --git a/src/main/java/net/neoforged/moddevgradle/internal/UserDevConfig.java b/src/main/java/net/neoforged/moddevgradle/internal/UserDevConfig.java
index 364cff3..4327c8d 100644
--- a/src/main/java/net/neoforged/moddevgradle/internal/UserDevConfig.java
+++ b/src/main/java/net/neoforged/moddevgradle/internal/UserDevConfig.java
@@ -6,11 +6,12 @@
 import java.io.File;
 import java.io.Serializable;
 import java.nio.file.Files;
-import java.util.List;
 import java.util.Map;
 
-public record UserDevConfig(String mcp, String sources, String universal, List<String> libraries, List<String> modules,
-                            Map<String, UserDevRunType> runs) implements Serializable {
+/**
+ * Sourced from the userdev config json. The run templates are the only thing that we use.
+ */
+public record UserDevConfig(Map<String, UserDevRunType> runs) implements Serializable {
     public static UserDevConfig from(File userDevFile) {
         try (var reader = Files.newBufferedReader(userDevFile.toPath())) {
             return new Gson().fromJson(reader, UserDevConfig.class);
diff --git a/src/main/java/net/neoforged/moddevgradle/internal/UserDevRunType.java b/src/main/java/net/neoforged/moddevgradle/internal/UserDevRunType.java
index 27ffb86..ff8a3c9 100644
--- a/src/main/java/net/neoforged/moddevgradle/internal/UserDevRunType.java
+++ b/src/main/java/net/neoforged/moddevgradle/internal/UserDevRunType.java
@@ -4,6 +4,5 @@
 import java.util.Map;
 
 public record UserDevRunType(boolean singleInstance, String main, List<String> args, List<String> jvmArgs,
-                             boolean client, boolean server, boolean dataGenerator, boolean gameTest,
                              Map<String, String> env, Map<String, String> props) {
 }
diff --git a/src/main/java/net/neoforged/moddevgradle/internal/utils/VersionUtils.java b/src/main/java/net/neoforged/moddevgradle/internal/utils/VersionUtils.java
new file mode 100644
index 0000000..cd10680
--- /dev/null
+++ b/src/main/java/net/neoforged/moddevgradle/internal/utils/VersionUtils.java
@@ -0,0 +1,38 @@
+package net.neoforged.moddevgradle.internal.utils;
+
+import java.util.Objects;
+import java.util.regex.Pattern;
+
+public final class VersionUtils {
+    private VersionUtils() {}
+
+    private static final Pattern RELEASE_PATTERN = Pattern.compile("1\\.(\\d+)(?:.(\\d+))?(?:-.*)?$");
+
+    /**
+     * Checks whether the provided NeoForm version should have split client and server data runs.
+     */
+    public static boolean hasSplitDataRuns(String neoFormVersion) {
+        // Snapshots starting from 24w45a
+        if (neoFormVersion.length() >= 5 && neoFormVersion.charAt(2) == 'w') {
+            try {
+                var year = Integer.parseInt(neoFormVersion.substring(0, 2));
+                var week = Integer.parseInt(neoFormVersion.substring(3, 5));
+
+                return year > 24 || (year == 24 && week >= 45);
+            } catch (NumberFormatException ignored) {}
+        }
+        // Releases starting from 1.21.4
+        var matcher = RELEASE_PATTERN.matcher(neoFormVersion);
+        if (matcher.find()) {
+            try {
+                int minor = Integer.parseInt(matcher.group(1));
+                // If there is no patch version, the second group has a null value
+                int patch = Integer.parseInt(Objects.requireNonNullElse(matcher.group(2), "0"));
+
+                return minor > 21 || (minor == 21 && patch >= 4);
+            } catch (NumberFormatException ignored) {}
+        }
+        // Assume other version patterns are newer and therefore split
+        return true;
+    }
+}
diff --git a/src/test/java/net/neoforged/moddevgradle/internal/VersionUtilsTest.java b/src/test/java/net/neoforged/moddevgradle/internal/VersionUtilsTest.java
new file mode 100644
index 0000000..c497fe4
--- /dev/null
+++ b/src/test/java/net/neoforged/moddevgradle/internal/VersionUtilsTest.java
@@ -0,0 +1,49 @@
+package net.neoforged.moddevgradle.internal;
+
+import net.neoforged.moddevgradle.internal.utils.VersionUtils;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class VersionUtilsTest {
+    @ParameterizedTest()
+    @CsvSource({
+            "1.21.4,true",
+            "1.21.4-pre1-20241120.190508,true",
+            "1.21.3,false",
+            "24w45a,true",
+            "24w44a,false",
+            "1.21.3-pre1,false",
+            "25w01a,true",
+            "23w07a,false",
+            "1.20,false",
+            "1.20-pre1,false",
+            "1.21,false",
+            "1.21-pre1-20240529.150918,false",
+            "1.21-pre1,false",
+            "1.22,true",
+            "1.22-pre1,true"
+    })
+    public void testSplitDataRunsCorrectness(String neoFormVersion, boolean splitDataRuns) {
+        assertThat(VersionUtils.hasSplitDataRuns(neoFormVersion))
+                .isEqualTo(splitDataRuns);
+    }
+
+    @ParameterizedTest
+    @CsvSource({
+            "1",
+            "1.",
+            "1.21.",
+            "test",
+            "24w",
+            "24w5",
+            "24w50",
+            "2aw50",
+            "24242",
+    })
+    public void testSplitDataRunsDoesNotCrash(String neoFormVersion) {
+        assertThat(VersionUtils.hasSplitDataRuns(neoFormVersion))
+                .isTrue();
+    }
+}