diff --git a/src/main/resources/META-INF/coremods.json b/src/main/resources/META-INF/coremods.json
new file mode 100644
index 00000000..29f9189b
--- /dev/null
+++ b/src/main/resources/META-INF/coremods.json
@@ -0,0 +1 @@
+{ "arnicalib.fishing_rod_item": "coremods/fishing_rod_item.js" }
diff --git a/src/main/resources/coremods/fishing_rod_item.js b/src/main/resources/coremods/fishing_rod_item.js
new file mode 100644
index 00000000..2724dddc
--- /dev/null
+++ b/src/main/resources/coremods/fishing_rod_item.js
@@ -0,0 +1,185 @@
+function initializeCoreMod() {
+    ASMAPI = Java.type('net.minecraftforge.coremod.api.ASMAPI');
+
+    Opcodes = Java.type('org.objectweb.asm.Opcodes');
+
+    InsnList = Java.type('org.objectweb.asm.tree.InsnList');
+
+    VarInsnNode = Java.type('org.objectweb.asm.tree.VarInsnNode');
+    MethodInsnNode = Java.type('org.objectweb.asm.tree.MethodInsnNode');
+    LabelNode = Java.type('org.objectweb.asm.tree.LabelNode');
+    LocalVariableNode = Java.type('org.objectweb.asm.tree.LocalVariableNode');
+
+    return {
+        'FishingRodItem#use': {
+            target: {
+                type: 'METHOD',
+                class: 'net.minecraft.world.item.FishingRodItem',
+                methodName: ASMAPI.mapMethod('m_7203_'),
+                methodDesc:
+                    '(Lnet/minecraft/world/level/Level;Lnet/minecraft/world/entity/player/Player;Lnet/minecraft/world/InteractionHand;)Lnet/minecraft/world/InteractionResultHolder;',
+            },
+            transformer: function (methodNode) {
+                var toInject = new InsnList();
+                {
+                    var fn_start = new LabelNode();
+                    var fn_end = new LabelNode();
+                    methodNode.localVariables.add(
+                        new LocalVariableNode(
+                            'preEvent',
+                            'Lorg/auioc/mcmod/arnicalib/server/event/impl/FishingRodCastEvent$Pre;',
+                            null,
+                            fn_start,
+                            fn_end,
+                            7
+                        )
+                    );
+                    toInject.add(fn_start);
+                    toInject.add(new VarInsnNode(Opcodes.ALOAD, 2));
+                    toInject.add(new VarInsnNode(Opcodes.ALOAD, 1));
+                    toInject.add(new VarInsnNode(Opcodes.ALOAD, 4));
+                    toInject.add(new VarInsnNode(Opcodes.ILOAD, 5));
+                    toInject.add(new VarInsnNode(Opcodes.ILOAD, 6));
+                    toInject.add(
+                        new MethodInsnNode(
+                            Opcodes.INVOKESTATIC,
+                            'org/auioc/mcmod/arnicalib/server/event/ServerEventFactory',
+                            'firePreFishingRodCastEvent',
+                            '(Lnet/minecraft/world/entity/player/Player;Lnet/minecraft/world/level/Level;Lnet/minecraft/world/item/ItemStack;II)Lorg/auioc/mcmod/arnicalib/server/event/impl/FishingRodCastEvent$Pre;',
+                            false
+                        )
+                    );
+                    toInject.add(new VarInsnNode(Opcodes.ASTORE, 7));
+                    toInject.add(new VarInsnNode(Opcodes.ALOAD, 7));
+                    toInject.add(
+                        new MethodInsnNode(
+                            Opcodes.INVOKEVIRTUAL,
+                            'org/auioc/mcmod/arnicalib/server/event/impl/FishingRodCastEvent$Pre',
+                            'getSpeedBonus',
+                            '()I',
+                            false
+                        )
+                    );
+                    toInject.add(new VarInsnNode(Opcodes.ISTORE, 5));
+                    toInject.add(new VarInsnNode(Opcodes.ALOAD, 7));
+                    toInject.add(
+                        new MethodInsnNode(
+                            Opcodes.INVOKEVIRTUAL,
+                            'org/auioc/mcmod/arnicalib/server/event/impl/FishingRodCastEvent$Pre',
+                            'getLuckBonus',
+                            '()I',
+                            false
+                        )
+                    );
+                    toInject.add(new VarInsnNode(Opcodes.ISTORE, 6));
+                    toInject.add(fn_end);
+                }
+
+                var at = ASMAPI.findFirstInstructionBefore(
+                    methodNode,
+                    Opcodes.NEW,
+                    0
+                );
+                methodNode.instructions.insertBefore(
+                    methodNode.instructions.get(
+                        methodNode.instructions.indexOf(at) - 1
+                    ),
+                    toInject
+                );
+
+                methodNode.visitMaxs(14, 8);
+
+                // print(ASMAPI.methodNodeToString(methodNode));
+                return methodNode;
+            },
+        },
+    };
+}
+
+//! SRG <-> MCP
+/*
+    m_7203_    use
+*/
+
+//! LocalVariableTable
+/*
+    Slot    Name         Signature
+    5       i            I
+    5       j            I
+    6       k            I
+    0       this         Lnet/minecraft/world/item/FishingRodItem;
+    1       p_41290_     Lnet/minecraft/world/level/Level;
+    2       p_41291_     Lnet/minecraft/world/entity/player/Player;
+    3       p_41292_     Lnet/minecraft/world/InteractionHand;
+    4       itemstack    Lnet/minecraft/world/item/ItemStack;
++   7       preEvent     Lorg/auioc/mcmod/arnicalib/server/event/impl/FishingRodCastEvent$Pre;
+*/
+
+//! Code
+/*
+    public InteractionResultHolder<ItemStack> use(Level p_41290_, Player p_41291_, InteractionHand p_41292_) {
+        ItemStack itemstack = p_41291_.getItemInHand(p_41292_);
+        if (p_41291_.fishing != null) {
+            //_ ...
+        } else {
+            //_ ...
+            if (!p_41290_.isClientSide) {
+                int k = EnchantmentHelper.getFishingSpeedBonus(itemstack);
+                int j = EnchantmentHelper.getFishingLuckBonus(itemstack);
++               var preEvent = org.auioc.mcmod.arnicalib.server.event.ServerEventFactory.firePreFishingRodCastEvent(p_41291_, p_41290_, itemstack, k, j);
++               k = preEvent.getSpeedBonus();
++               j = preEvent.getLuckBonus();
+                p_41290_.addFreshEntity(new FishingHook(p_41291_, p_41290_, j, k));
+            }
+            //_ ...
+       }
+       return InteractionResultHolder.sidedSuccess(itemstack, p_41290_.isClientSide());
+    }
+*   ========== ByteCode ==========   *
+    //_ ...
+    L9
+        LINENUMBER 33 L9
+        ALOAD 1
+        GETFIELD net/minecraft/world/level/Level.isClientSide : Z
+        IFNE L10
+    L11
+        LINENUMBER 34 L11
+        ALOAD 4
+        INVOKESTATIC net/minecraft/world/item/enchantment/EnchantmentHelper.getFishingSpeedBonus (Lnet/minecraft/world/item/ItemStack;)I
+        ISTORE 5
+    L12
+        LINENUMBER 35 L12
+        ALOAD 4
+        INVOKESTATIC net/minecraft/world/item/enchantment/EnchantmentHelper.getFishingLuckBonus (Lnet/minecraft/world/item/ItemStack;)I
+        ISTORE 6
+    L13
+        LINENUMBER 36 L13
++   L14
++       ALOAD 2
++       ALOAD 1
++       ALOAD 4
++       ILOAD 5
++       ILOAD 6
++       INVOKESTATIC org/auioc/mcmod/arnicalib/server/event/ServerEventFactory.firePreFishingRodCastEvent (Lnet/minecraft/world/entity/player/Player;Lnet/minecraft/world/level/Level;Lnet/minecraft/world/item/ItemStack;II)Lorg/auioc/mcmod/arnicalib/server/event/impl/FishingRodCastEvent$Pre;
++       ASTORE 7
++       ALOAD 7
++       INVOKEVIRTUAL org/auioc/mcmod/arnicalib/server/event/impl/FishingRodCastEvent$Pre.getSpeedBonus ()I
++       ISTORE 5
++       ALOAD 7
++       INVOKEVIRTUAL org/auioc/mcmod/arnicalib/server/event/impl/FishingRodCastEvent$Pre.getLuckBonus ()I
++       ISTORE 6
++   L15
+        ALOAD 1
+        NEW net/minecraft/world/entity/projectile/FishingHook
+        DUP
+        ALOAD 2
+        ALOAD 1
+        ILOAD 6
+        ILOAD 5
+        INVOKESPECIAL net/minecraft/world/entity/projectile/FishingHook.<init> (Lnet/minecraft/world/entity/player/Player;Lnet/minecraft/world/level/Level;II)V
+        INVOKEVIRTUAL net/minecraft/world/level/Level.addFreshEntity (Lnet/minecraft/world/entity/Entity;)Z
+        POP
+    //_ ...
+-    MAXLOCALS = 7
++    MAXLOCALS = 8
+*/