DreamyXiam · Sep 20, 2026
diff --git a/Bootstrap/Core/build.gradle b/Bootstrap/Core/build.gradle
@@ -3,4 +3,8 @@ dependencies {
     implementation 'org.ow2.asm:asm:9.9.1'
     implementation 'org.ow2.asm:asm-commons:9.9.1'
     implementation 'org.ow2.asm:asm-tree:9.9.1'
+    testImplementation 'junit:junit:4.13.2'
+    testRuntimeOnly 'com.google.code.gson:gson:2.14.0'
+    testRuntimeOnly 'org.apache.logging.log4j:log4j-api:2.26.0'
+    testRuntimeOnly 'org.apache.logging.log4j:log4j-core:2.26.0'
 }
diff --git a/Bootstrap/Core/src/main/java/customskinloader/bootstrap/transformer/patch/PatchSupport.java b/Bootstrap/Core/src/main/java/customskinloader/bootstrap/transformer/patch/PatchSupport.java
@@ -100,6 +100,7 @@ abstract class PatchSupport extends TargetedClassTransformer implements Opcodes
     protected static final String MINECRAFT_PROFILE_TEXTURE = "com/mojang/authlib/minecraft/MinecraftProfileTexture";
     protected static final String MINECRAFT_PROFILE_TEXTURE_TYPE = "com/mojang/authlib/minecraft/MinecraftProfileTexture$Type";
     protected static final String MINECRAFT_SESSION_SERVICE = "com/mojang/authlib/minecraft/MinecraftSessionService";
+    protected static final String SESSION_SERVICE = "com/mojang/authlib/minecraft/SessionService";
     protected static final String MINECRAFT_PROFILE_TEXTURES = "com/mojang/authlib/minecraft/MinecraftProfileTextures";
     protected static final String GAME_PROFILE = "com/mojang/authlib/GameProfile";
     protected static final String PROPERTY = "com/mojang/authlib/properties/Property";

diff --git a/...rap/Core/src/main/java/customskinloader/bootstrap/transformer/patch/SkinManagerPatch.java b/...rap/Core/src/main/java/customskinloader/bootstrap/transformer/patch/SkinManagerPatch.java
@@ -413,7 +413,7 @@ private boolean replaceGetTexturesWithFakeUserProfile(MethodNode methodNode) {
                 continue;
             }
 
-            methodNode.instructions.set(instruction, new MethodInsnNode(INVOKESTATIC, FAKE_SKIN_MANAGER, "getUserProfile", "(" + objectDesc(MINECRAFT_SESSION_SERVICE) + objectDesc(GAME_PROFILE) + "Z)" + objectDesc(MAP), false));
+            methodNode.instructions.set(instruction, new MethodInsnNode(INVOKESTATIC, FAKE_SKIN_MANAGER, "getUserProfile", "(" + objectDesc(OBJECT) + objectDesc(GAME_PROFILE) + "Z)" + objectDesc(MAP), false));
             modified = true;
         }
         return modified;
@@ -489,15 +489,15 @@ private boolean replaceGetTexturesWithFakeSkinCache(MethodNode methodNode) {
                 continue;
             }
 
-            methodNode.instructions.set(instruction, new MethodInsnNode(INVOKESTATIC, FAKE_SKIN_MANAGER, "loadSkinFromCache", "(" + objectDesc(MINECRAFT_SESSION_SERVICE) + objectDesc(GAME_PROFILE) + "Z)" + objectDesc(MAP), false));
+            methodNode.instructions.set(instruction, new MethodInsnNode(INVOKESTATIC, FAKE_SKIN_MANAGER, "loadSkinFromCache", "(" + objectDesc(OBJECT) + objectDesc(GAME_PROFILE) + "Z)" + objectDesc(MAP), false));
             modified = true;
         }
         return modified;
     }
 
     private boolean replaceUnpackTexturesWithFakeSkinCache(ClassTransformationContext context, MethodNode methodNode) {
         boolean modified = false;
-        String desc = context.remapMethodDescriptor("(" + objectDesc(MINECRAFT_SESSION_SERVICE) + objectDesc(PROPERTY) + objectDesc(SKIN_MANAGER_CACHE_KEY) + ")" + objectDesc(OBJECT));
+        String desc = context.remapMethodDescriptor("(" + objectDesc(OBJECT) + objectDesc(PROPERTY) + objectDesc(SKIN_MANAGER_CACHE_KEY) + ")" + objectDesc(OBJECT));
         String returnType = context.remapClassName(MINECRAFT_PROFILE_TEXTURES);
 
         for (AbstractInsnNode instruction : methodNode.instructions.toArray()) {
@@ -506,7 +506,7 @@ private boolean replaceUnpackTexturesWithFakeSkinCache(ClassTransformationContex
             }
 
             MethodInsnNode methodInsnNode = (MethodInsnNode) instruction;
-            if (!MINECRAFT_SESSION_SERVICE.equals(methodInsnNode.owner) || !"unpackTextures".equals(methodInsnNode.name) || !("(" + objectDesc(PROPERTY) + ")" + objectDesc(MINECRAFT_PROFILE_TEXTURES)).equals(methodInsnNode.desc)) {
+            if ((!MINECRAFT_SESSION_SERVICE.equals(methodInsnNode.owner) && !SESSION_SERVICE.equals(methodInsnNode.owner)) || !"unpackTextures".equals(methodInsnNode.name) || !("(" + objectDesc(PROPERTY) + ")" + objectDesc(MINECRAFT_PROFILE_TEXTURES)).equals(methodInsnNode.desc)) {
                 continue;
             }
 

diff --git a/...Core/src/test/java/customskinloader/bootstrap/transformer/patch/SkinManagerPatchTest.java b/...Core/src/test/java/customskinloader/bootstrap/transformer/patch/SkinManagerPatchTest.java
@@ -0,0 +1,64 @@
+package customskinloader.bootstrap.transformer.patch;
+
+import customskinloader.bootstrap.mapping.Mappings;
+import customskinloader.bootstrap.transformer.ClassTransformationContext;
+import org.junit.Test;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.InsnNode;
+import org.objectweb.asm.tree.MethodInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public final class SkinManagerPatchTest implements Opcodes {
+    private static final String CACHE_KEY = "net/minecraft/client/resources/SkinManager$CacheKey";
+    private static final String SERVICES = "net/minecraft/server/Services";
+    private static final String PROFILE_TEXTURES = "com/mojang/authlib/minecraft/MinecraftProfileTextures";
+    private static final String SESSION_SERVICE = "com/mojang/authlib/minecraft/SessionService";
+    private static final String PROPERTY = "com/mojang/authlib/properties/Property";
+
+    @Test
+    public void transformsMinecraft26_3SessionServiceInterfaceInvocation() {
+        ClassNode classNode = new ClassNode();
+        classNode.name = "net/minecraft/client/resources/SkinManager$1";
+        classNode.methods.add(createLoadMethod());
+        classNode.methods.add(createMinecraft26_3Lambda());
+
+        ClassTransformationContext context = ClassTransformationContext.create(classNode.name, classNode, Mappings.EMPTY);
+        assertTrue(new SkinManagerPatch().transform(context));
+
+        MethodNode lambda = classNode.methods.get(1);
+        assertFalse(containsInvocation(lambda, SESSION_SERVICE, "unpackTextures"));
+        assertTrue(containsInvocation(lambda, "customskinloader/fake/FakeSkinManager", "loadSkinFromCache"));
+    }
+
+    private static MethodNode createLoadMethod() {
+        MethodNode method = new MethodNode(ACC_PUBLIC, "load", "(L" + CACHE_KEY + ";)Ljava/util/concurrent/CompletableFuture;", null, null);
+        method.instructions.add(new MethodInsnNode(INVOKESTATIC, "java/util/concurrent/CompletableFuture", "supplyAsync", "(Ljava/util/function/Supplier;Ljava/util/concurrent/Executor;)Ljava/util/concurrent/CompletableFuture;", false));
+        method.instructions.add(new MethodInsnNode(INVOKEVIRTUAL, "java/util/concurrent/CompletableFuture", "thenComposeAsync", "(Ljava/util/function/Function;Ljava/util/concurrent/Executor;)Ljava/util/concurrent/CompletableFuture;", false));
+        method.instructions.add(new InsnNode(ARETURN));
+        return method;
+    }
+
+    private static MethodNode createMinecraft26_3Lambda() {
+        MethodNode method = new MethodNode(ACC_PRIVATE | ACC_STATIC, "lambda$load$0", "(L" + CACHE_KEY + ";L" + SERVICES + ";)L" + PROFILE_TEXTURES + ";", null, null);
+        method.instructions.add(new MethodInsnNode(INVOKEINTERFACE, SESSION_SERVICE, "unpackTextures", "(L" + PROPERTY + ";)L" + PROFILE_TEXTURES + ";", true));
+        method.instructions.add(new InsnNode(ARETURN));
+        return method;
+    }
+
+    private static boolean containsInvocation(MethodNode method, String owner, String name) {
+        for (AbstractInsnNode instruction : method.instructions.toArray()) {
+            if (instruction instanceof MethodInsnNode) {
+                MethodInsnNode invocation = (MethodInsnNode) instruction;
+                if (owner.equals(invocation.owner) && name.equals(invocation.name)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+}
diff --git a/Bootstrap/Core/src/test/resources/version.json b/Bootstrap/Core/src/test/resources/version.json
@@ -0,0 +1,4 @@
+{
+  "protocol_version": 777,
+  "world_version": 0
+}
diff --git a/Common/src/main/java/customskinloader/fake/FakeSkinManager.java b/Common/src/main/java/customskinloader/fake/FakeSkinManager.java
@@ -12,7 +12,6 @@
 import com.mojang.authlib.SignatureState;
 import com.mojang.authlib.minecraft.MinecraftProfileTexture;
 import com.mojang.authlib.minecraft.MinecraftProfileTextures;
-import com.mojang.authlib.minecraft.MinecraftSessionService;
 import com.mojang.authlib.properties.Property;
 import com.mojang.blaze3d.platform.NativeImage;
 import customskinloader.CustomSkinLoader;
@@ -27,18 +26,18 @@
 public class FakeSkinManager {
     /**
      * 1.20.1-
-     * Invoked from {@link SkinManager(TextureManager, File, MinecraftSessionService)}
+     * Invoked from SkinManager(TextureManager, File, MinecraftSessionService)
      */
     public static void setSkinCacheDir(File skinCacheDirectory) {
         HttpTextureUtil.defaultCacheDir = skinCacheDirectory;
     }
 
     /**
      * 23w31a ~ 23w45a
-     * Invoked from {@link SkinManager(TextureManager, Path, MinecraftSessionService, Executor)}
+     * Invoked from SkinManager(TextureManager, Path, MinecraftSessionService, Executor)
      *
      * 23w46a ~ 25w33a
-     * Invoked from {@link SkinManager(Path, MinecraftSessionService, Executor)}
+     * Invoked from SkinManager(Path, MinecraftSessionService, Executor)
      *
      * 25w34a+
      * Invoked from {@link SkinManager(Path, Services, Executor)}
@@ -67,7 +66,7 @@ public static Executor loadProfileTextures(Executor executor) {
      * 1.20.1-
      * Invoked from {@link SkinManager#lambda$registerSkins$4(GameProfile, boolean, SkinManager$SkinTextureCallback)}
      */
-    public static Map<MinecraftProfileTexture.Type, MinecraftProfileTexture> getUserProfile(MinecraftSessionService sessionService, GameProfile profile, boolean requireSecure) {
+    public static Map<MinecraftProfileTexture.Type, MinecraftProfileTexture> getUserProfile(Object sessionService, GameProfile profile, boolean requireSecure) {
         return ModelManager0.fromUserProfile(CustomSkinLoader.loadProfile(profile));
     }
 
@@ -81,24 +80,28 @@ public static Map<MinecraftProfileTexture.Type, MinecraftProfileTexture> loadSki
 
     /**
      * 23w31a ~ 23w41a
-     * Invoked from {@link SkinManager$1#lambda$load$0(MinecraftSessionService, GameProfile)}
+     * Invoked from SkinManager$1.lambda$load$0(MinecraftSessionService, GameProfile)
      */
-    public static Map<MinecraftProfileTexture.Type, MinecraftProfileTexture> loadSkinFromCache(MinecraftSessionService sessionService, GameProfile profile, boolean requireSecure) {
+    public static Map<MinecraftProfileTexture.Type, MinecraftProfileTexture> loadSkinFromCache(Object sessionService, GameProfile profile, boolean requireSecure) {
         return getUserProfile(sessionService, profile, requireSecure);
     }
 
     /**
      * 23w42a ~ 25w33a
-     * Invoked from {@link SkinManager$1#lambda$load$0(SkinManager$CacheKey, MinecraftSessionService)}
+     * Invoked from SkinManager$1.lambda$load$0(SkinManager$CacheKey, MinecraftSessionService)
      *
      * 25w34a+
      * Invoked from {@link SkinManager$1#lambda$load$0(SkinManager$CacheKey, Services)}
      */
-    public static Object loadSkinFromCache(MinecraftSessionService sessionService, Property property, SkinManager$CacheKey cacheKey) {
+    public static Object loadSkinFromCache(Object sessionService, Property property, SkinManager$CacheKey cacheKey) {
         if (cacheKey instanceof FakeCacheKey) {
             return FakeCacheKey.createMinecraftProfileTextures(loadSkinFromCache(sessionService, ((FakeCacheKey) cacheKey).profile(), false));
         }
-        return sessionService.unpackTextures(property);
+        try {
+            return sessionService.getClass().getMethod("unpackTextures", Property.class).invoke(sessionService, property);
+        } catch (ReflectiveOperationException exception) {
+            throw new RuntimeException(exception);
+        }
     }
 
     public static class BaseBuffer implements FakeHttpTextureProcessor {

diff --git a/Common/src/main/java/customskinloader/loader/GameProfileLoader.java b/Common/src/main/java/customskinloader/loader/GameProfileLoader.java
@@ -14,7 +14,6 @@
 import com.mojang.authlib.minecraft.MinecraftProfileTexture;
 import com.mojang.authlib.properties.Property;
 import com.mojang.authlib.properties.PropertyMap;
-import com.mojang.authlib.yggdrasil.response.MinecraftTexturesPayload;
 import com.mojang.util.UUIDTypeAdapter;
 import customskinloader.CustomSkinLoader;
 import customskinloader.config.SkinSiteProfile;
@@ -101,10 +100,14 @@ public static Map<MinecraftProfileTexture.Type, MinecraftProfileTexture> getText
         if (result == null) {
             return Maps.newHashMap();
         }
-        Map<MinecraftProfileTexture.Type, MinecraftProfileTexture> textures = TextureUtil.AuthlibField.MINECRAFT_TEXTURES_PAYLOAD_TEXTURES.get(result);
+        Map<MinecraftProfileTexture.Type, MinecraftProfileTexture> textures = result.textures;
         if (textures == null) {
             return Maps.newHashMap();
         }
         return textures;
     }
+
+    private static final class MinecraftTexturesPayload {
+        private Map<MinecraftProfileTexture.Type, MinecraftProfileTexture> textures;
+    }
 }
diff --git a/Common/src/main/java/customskinloader/loader/MojangAPILoader.java b/Common/src/main/java/customskinloader/loader/MojangAPILoader.java
@@ -11,7 +11,6 @@
 import com.mojang.authlib.GameProfile;
 import com.mojang.authlib.minecraft.MinecraftProfileTexture;
 import com.mojang.authlib.properties.PropertyMap;
-import com.mojang.authlib.yggdrasil.response.MinecraftProfilePropertiesResponse;
 import customskinloader.CustomSkinLoader;
 import customskinloader.config.SkinSiteProfile;
 import customskinloader.plugin.ICustomSkinLoaderPlugin;
@@ -81,12 +80,12 @@ public String getSessionRoot() {
     @Override
     public UserProfile loadProfile(SkinSiteProfile ssp, GameProfile gameProfile) {
         String username = TextureUtil.AuthlibField.GAME_PROFILE_NAME.get(gameProfile);
-        MinecraftProfilePropertiesResponse newProfile = loadGameProfileCached(ssp.apiRoot, username);
+        MojangProfile newProfile = loadGameProfileCached(ssp.apiRoot, username);
         if (newProfile == null) {
             CustomSkinLoader.logger.info("Profile not found.(" + username + "'s profile not found.)");
             return null;
         }
-        PropertyMap propertyMap = TextureUtil.AuthlibField.MINECRAFT_PROFILE_PROPERTIES_RESPONSE_PROPERTIES.get(fillProfile(ssp.sessionRoot, newProfile));
+        PropertyMap propertyMap = fillProfile(ssp.sessionRoot, newProfile).properties;
         if (propertyMap != null) {
             Map<MinecraftProfileTexture.Type, MinecraftProfileTexture> map = GameProfileLoader.getTextures(propertyMap);
             if (!map.isEmpty()) {
@@ -97,26 +96,26 @@ public UserProfile loadProfile(SkinSiteProfile ssp, GameProfile gameProfile) {
         return null;
     }
 
-    private static final Map<String, MinecraftProfilePropertiesResponse> gameProfileCache = new ConcurrentHashMap<>();
+    private static final Map<String, MojangProfile> gameProfileCache = new ConcurrentHashMap<>();
 
-    public static MinecraftProfilePropertiesResponse loadGameProfileCached(String apiRoot, String username) {
+    public static MojangProfile loadGameProfileCached(String apiRoot, String username) {
         return gameProfileCache.computeIfAbsent(apiRoot + " " + username, ignored -> loadGameProfile(apiRoot, username));
     }
 
     //Username -> UUID
-    public static MinecraftProfilePropertiesResponse loadGameProfile(String apiRoot, String username) {
+    public static MojangProfile loadGameProfile(String apiRoot, String username) {
         //Doc (https://minecraft.wiki/w/Mojang_API#Query_player_UUIDs_in_batch)
         HttpRequestUtil.HttpResponce responce = HttpRequestUtil.makeHttpRequest(new HttpRequestUtil.HttpRequest(apiRoot + "profiles/minecraft").setCacheTime(600).setPayload(GameProfileLoader.GSON.toJson(Collections.singletonList(username))));
         if (StringUtils.isEmpty(responce.content)) {
             return null;
         }
 
-        MinecraftProfilePropertiesResponse[] profiles = GameProfileLoader.GSON.fromJson(responce.content, MinecraftProfilePropertiesResponse[].class);
+        MojangProfile[] profiles = GameProfileLoader.GSON.fromJson(responce.content, MojangProfile[].class);
         if (profiles.length == 0) {
             return null;
         }
 
-        UUID id = TextureUtil.AuthlibField.MINECRAFT_PROFILE_PROPERTIES_RESPONSE_ID.get(profiles[0]);
+        UUID id = profiles[0].id;
         if (id == null) {
             return null;
         }
@@ -131,22 +130,27 @@ public static MinecraftProfilePropertiesResponse loadGameProfile(String apiRoot,
      * @return UUID in Mojang API style string. Returns {@code null} if username not found in Mojang API.
      */
     public static String getMojangUuidByUsername(String username, boolean standard) {
-        MinecraftProfilePropertiesResponse profile = loadGameProfileCached(getMojangApiRoot(), username);
+        MojangProfile profile = loadGameProfileCached(getMojangApiRoot(), username);
         if (profile == null) {
             return null;
         }
-        UUID id = TextureUtil.AuthlibField.MINECRAFT_PROFILE_PROPERTIES_RESPONSE_ID.get(profile);
+        UUID id = profile.id;
         return standard ? id.toString() : TextureUtil.fromUUID(id);
     }
 
     //UUID -> Profile
-    public static MinecraftProfilePropertiesResponse fillProfile(String sessionRoot, MinecraftProfilePropertiesResponse profile) {
+    public static MojangProfile fillProfile(String sessionRoot, MojangProfile profile) {
         //Doc (https://minecraft.wiki/w/Mojang_API#Query_player's_skin_and_cape)
-        HttpRequestUtil.HttpResponce responce = HttpRequestUtil.makeHttpRequest(new HttpRequestUtil.HttpRequest(sessionRoot + "session/minecraft/profile/" + TextureUtil.fromUUID(TextureUtil.AuthlibField.MINECRAFT_PROFILE_PROPERTIES_RESPONSE_ID.get(profile))).setCacheTime(90));
+        HttpRequestUtil.HttpResponce responce = HttpRequestUtil.makeHttpRequest(new HttpRequestUtil.HttpRequest(sessionRoot + "session/minecraft/profile/" + TextureUtil.fromUUID(profile.id)).setCacheTime(90));
         if (StringUtils.isEmpty(responce.content)) {
             return profile;
         }
-        return GameProfileLoader.GSON.fromJson(responce.content, MinecraftProfilePropertiesResponse.class);
+        return GameProfileLoader.GSON.fromJson(responce.content, MojangProfile.class);
+    }
+
+    public static final class MojangProfile {
+        private UUID id;
+        private PropertyMap properties;
     }
 
     @Override

diff --git a/Common/src/main/java/customskinloader/utils/TextureUtil.java b/Common/src/main/java/customskinloader/utils/TextureUtil.java
@@ -6,8 +6,6 @@
 
 import com.mojang.authlib.GameProfile;
 import com.mojang.authlib.properties.Property;
-import com.mojang.authlib.yggdrasil.response.MinecraftProfilePropertiesResponse;
-import com.mojang.authlib.yggdrasil.response.MinecraftTexturesPayload;
 import customskinloader.CustomSkinLoader;
 import org.apache.commons.codec.binary.Base64;
 import org.apache.commons.io.FileUtils;
@@ -43,10 +41,7 @@ public enum AuthlibField {
         GAME_PROFILE_ID(GameProfile.class, "id"),
         GAME_PROFILE_NAME(GameProfile.class, "name"),
         GAME_PROFILE_PROPERTIES(GameProfile.class, "properties"),
-        PROPERTY_VALUE(Property.class, "value"),
-        MINECRAFT_PROFILE_PROPERTIES_RESPONSE_ID(MinecraftProfilePropertiesResponse.class, "id"),
-        MINECRAFT_PROFILE_PROPERTIES_RESPONSE_PROPERTIES(MinecraftProfilePropertiesResponse.class, "properties"),
-        MINECRAFT_TEXTURES_PAYLOAD_TEXTURES(MinecraftTexturesPayload.class, "textures");
+        PROPERTY_VALUE(Property.class, "value");
 
         private final Field field;
 

diff --git a/build.info.json b/build.info.json
@@ -22,7 +22,7 @@
         "1.19", "1.19.1", "1.19.2", "1.19.3", "1.19.4",
         "1.20", "1.20.1", "1.20.2", "1.20.3", "1.20.4", "1.20.5", "1.20.6",
         "1.21", "1.21.1", "1.21.2", "1.21.3", "1.21.4", "1.21.5", "1.21.6", "1.21.7", "1.21.8", "1.21.9", "1.21.10", "1.21.11",
-        "26.1", "26.1.1", "26.1.2", "26.2"
+        "26.1", "26.1.1", "26.1.2", "26.2", "26.3"
     ],
     "java": [
         8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 25

diff --git a/gradle.properties b/gradle.properties
@@ -1,7 +1,7 @@
 build_type=beta
 
-minecraft_version=26.2
-fabric_v1_version=0.19.3
+minecraft_version=26.3
+fabric_v1_version=0.19.5
 forge_v1_version=14.23.5.2864
 forge_v2_version=36.2.42
 neoforge_v1_version=20.6.13-beta