few more changes

adapters/fabric/src/main/java/art/arcane/iris/fabric/FabricForcedDatapackSources.java

@@ -0,0 +1,48 @@
+/*
+ * Iris is a World Generator for Minecraft Servers
+ * Copyright (c) 2026 Arcane Arts (Volmit Software)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package art.arcane.iris.fabric;
+
+import art.arcane.iris.modded.ModdedForcedDatapack;
+import net.minecraft.server.packs.repository.PackRepository;
+import net.minecraft.server.packs.repository.RepositorySource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+public final class FabricForcedDatapackSources {
+    private static final Logger LOGGER = LoggerFactory.getLogger("Iris");
+
+    private FabricForcedDatapackSources() {
+    }
+
+    public static void attach(PackRepository repository) {
+        if (repository == null) {
+            return;
+        }
+        try {
+            Set<RepositorySource> merged = new LinkedHashSet<>(repository.sources);
+            merged.add(ModdedForcedDatapack.repositorySource());
+            repository.sources = merged;
+        } catch (Throwable e) {
+            LOGGER.error("Iris failed to attach the forced startup datapack source to the server data pack repository", e);
+        }
+    }
+}

adapters/fabric/src/main/java/art/arcane/iris/fabric/IrisFabricBootstrap.java

@@ -72,13 +72,17 @@ public final class IrisFabricBootstrap implements ModInitializer {
             ModdedObjectUndo.clearAll();
             ModdedWandService.clearAll();
             ModdedWorldEngines.shutdown();
+            ModdedEngineBootstrap.stop();
         });
         CommandRegistrationCallback.EVENT.register((CommandDispatcher<CommandSourceStack> dispatcher, CommandBuildContext buildContext, Commands.CommandSelection selection) -> IrisModdedCommands.register(dispatcher));
         AttackBlockCallback.EVENT.register((Player player, Level level, InteractionHand hand, BlockPos pos, Direction direction) ->
                 ModdedWandService.attackBlock(player, level, hand, pos) ? InteractionResult.SUCCESS : InteractionResult.PASS);
         UseBlockCallback.EVENT.register((Player player, Level level, InteractionHand hand, BlockHitResult hit) ->
                 ModdedWandService.useBlock(player, level, hand, hit.getBlockPos()) ? InteractionResult.SUCCESS : InteractionResult.PASS);
-        ServerTickEvents.END_SERVER_TICK.register((MinecraftServer server) -> ModdedWandService.serverTick(server));
+        ServerTickEvents.END_SERVER_TICK.register((MinecraftServer server) -> {
+            ModdedEngineBootstrap.tick(server);
+            ModdedWandService.serverTick(server);
+        });
 
         String parity = System.getProperty("iris.parity");
         if (parity != null) {

adapters/fabric/src/main/java/art/arcane/iris/fabric/mixin/ServerPacksSourceMixin.java

@@ -0,0 +1,36 @@
+/*
+ * Iris is a World Generator for Minecraft Servers
+ * Copyright (c) 2026 Arcane Arts (Volmit Software)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package art.arcane.iris.fabric.mixin;
+
+import art.arcane.iris.fabric.FabricForcedDatapackSources;
+import net.minecraft.server.packs.repository.PackRepository;
+import net.minecraft.server.packs.repository.ServerPacksSource;
+import net.minecraft.world.level.storage.LevelStorageSource;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+@Mixin(ServerPacksSource.class)
+public class ServerPacksSourceMixin {
+    @Inject(method = "createPackRepository(Lnet/minecraft/world/level/storage/LevelStorageSource$LevelStorageAccess;)Lnet/minecraft/server/packs/repository/PackRepository;", at = @At("RETURN"))
+    private static void iris$addForcedDatapackSource(LevelStorageSource.LevelStorageAccess storage, CallbackInfoReturnable<PackRepository> info) {
+        FabricForcedDatapackSources.attach(info.getReturnValue());
+    }
+}

adapters/fabric/src/main/resources/fabric.mod.json

@@ -10,6 +10,8 @@
   },
   "license": "GPL-3.0",
   "environment": "*",
+  "accessWidener": "irisworldgen.accesswidener",
+  "mixins": ["irisworldgen.mixins.json"],
   "entrypoints": {
     "main": ["art.arcane.iris.fabric.IrisFabricBootstrap"]
   },

adapters/fabric/src/main/resources/irisworldgen.accesswidener

@@ -0,0 +1,6 @@
+accessWidener v2 official
+accessible field net/minecraft/server/MinecraftServer levels Ljava/util/Map;
+accessible field net/minecraft/server/MinecraftServer executor Ljava/util/concurrent/Executor;
+accessible field net/minecraft/server/MinecraftServer storageSource Lnet/minecraft/world/level/storage/LevelStorageSource$LevelStorageAccess;
+accessible field net/minecraft/server/packs/repository/PackRepository sources Ljava/util/Set;
+mutable field net/minecraft/server/packs/repository/PackRepository sources Ljava/util/Set;

adapters/fabric/src/main/resources/irisworldgen.mixins.json

@@ -0,0 +1,12 @@
+{
+  "required": true,
+  "minVersion": "0.8",
+  "package": "art.arcane.iris.fabric.mixin",
+  "compatibilityLevel": "JAVA_25",
+  "mixins": [
+    "ServerPacksSourceMixin"
+  ],
+  "injectors": {
+    "defaultRequire": 1
+  }
+}