diff --git a/build.gradle b/build.gradle
index db1f2b0..ba96044 100644
--- a/build.gradle
+++ b/build.gradle
@@ -30,8 +30,8 @@ dependencies {
     // Fabric API. This is technically optional, but you probably want it anyway.
     modImplementation "net.fabricmc.fabric-api:fabric-api:${project.fabric_version}"
     shadow('com.maxmind.geoip2:geoip2:4.2.0')
-    implementation "io.javalin:javalin:6.4.0"
-    implementation 'com.github.houbb:pinyin:0.4.0'
+    shadow("io.javalin:javalin:6.4.0")
+    shadow('com.github.houbb:pinyin:0.4.0')
     shadow('com.google.inject:guice:7.0.0') {
         exclude group: 'com.google.guava', module: 'guava'
         exclude group: 'com.google.guava', module: 'listenablefuture'
diff --git a/src/main/java/io/ib67/sfcraft/module/SignatureService.java b/src/main/java/io/ib67/sfcraft/module/SignatureService.java
index bf4a474..9616cb7 100644
--- a/src/main/java/io/ib67/sfcraft/module/SignatureService.java
+++ b/src/main/java/io/ib67/sfcraft/module/SignatureService.java
@@ -45,8 +45,9 @@ public class SignatureService {
     public byte[] createSignature(Signature signature) {
         var buf = Unpooled.buffer();
         writeSignature(buf, signature);
-        buf = buf.slice(0, buf.readableBytes());
-        return buf.array();
+        var arr = new byte[buf.readableBytes()];
+        buf.readBytes(arr);
+        return arr;
     }
 
     @SneakyThrows
diff --git a/src/main/java/io/ib67/sfcraft/util/Permission.java b/src/main/java/io/ib67/sfcraft/util/Permission.java
index 7b299de..4a55058 100644
--- a/src/main/java/io/ib67/sfcraft/util/Permission.java
+++ b/src/main/java/io/ib67/sfcraft/util/Permission.java
@@ -2,6 +2,7 @@ package io.ib67.sfcraft.util;
 
 import me.lucko.fabric.api.permissions.v0.Permissions;
 import net.minecraft.entity.Entity;
+import net.minecraft.entity.player.PlayerEntity;
 
 import java.util.Objects;
 
@@ -15,10 +16,19 @@ public record Permission<T extends Entity>(String key, boolean byDefault) {
     }
 
     public boolean hasPermission(T t) {
-        if (Permissions.check(t, SFConsts.SPECIAL_SUDO)) return true;
+        if (check(t, SFConsts.SPECIAL_SUDO)) return true;
         if (byDefault) {
-            return !Permissions.check(t, "-"+key);
+            return !check(t, "-"+key);
         }
-        return Permissions.check(t, key);
+        return check(t, key);
+    }
+
+    private boolean check(T t, String permission){
+        if(t instanceof PlayerEntity player) {
+            if (player.getCommandTags().contains(permission)){
+                return true;
+            }
+        }
+        return Permissions.check(t, permission);
     }
 }