diff --git a/app/build.gradle b/app/build.gradle
index b5efd0abc..ffe0e4d10 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -26,6 +26,21 @@ discordApplicationId = new BigInteger(discordApplicationId).toString()
 def discordLargeImage = providers.gradleProperty('discord.large_image')
         .getOrElse(discordProperties.getProperty('large_image', '')).trim()
 
+def curseForgeApiKey = localProperties.getProperty('curseforge.api_key', '').trim()
+
+// Fallback for local debug builds only: the same obfuscated key LeviLauncher
+// for Windows embeds (base64, then XOR 0xAF). Release and beta builds, and
+// every CI build, keep using the key from local.properties (CI fills it from
+// a secret).
+def curseForgeDebugApiKey = curseForgeApiKey
+if (curseForgeDebugApiKey.isEmpty() && !System.getenv('CI')) {
+    def embeddedKeyFile = file('curseforge-debug-apikey.bin')
+    if (embeddedKeyFile.exists()) {
+        def deobfuscated = embeddedKeyFile.bytes.collect { (byte) (it ^ 0xAF) } as byte[]
+        curseForgeDebugApiKey = new String(Base64.decoder.decode(new String(deobfuscated, 'US-ASCII')), 'UTF-8').trim()
+    }
+}
+
 def getGitTag() {
     def tag = "unknown"
     try {
@@ -60,7 +75,7 @@ android {
         versionCode getVersionCodeByTimestamp()
         versionName getGitTag()
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
-        buildConfigField "String", "CURSEFORGE_API_KEY", "\"${localProperties.getProperty('curseforge.api_key', '')}\""
+        buildConfigField "String", "CURSEFORGE_API_KEY", groovy.json.JsonOutput.toJson(curseForgeApiKey)
         buildConfigField 'long', 'DISCORD_APPLICATION_ID', "${discordApplicationId}L"
         buildConfigField 'String', 'DISCORD_LARGE_IMAGE', groovy.json.JsonOutput.toJson(discordLargeImage)
         ndk {
@@ -115,6 +130,7 @@ android {
                 debugSymbolLevel 'FULL'
             }
             buildConfigField "boolean", "IS_BETA", "false"
+            buildConfigField "String", "CURSEFORGE_API_KEY", groovy.json.JsonOutput.toJson(curseForgeDebugApiKey)
         }
         beta {
             initWith release
diff --git a/app/curseforge-debug-apikey.bin b/app/curseforge-debug-apikey.bin
new file mode 100644
index 000000000..84959af79
--- /dev/null
+++ b/app/curseforge-debug-apikey.bin
@@ -0,0 +1 @@
+��������������̚����������Ü�������������ȝ����������Ĝ�����������������������
\ No newline at end of file
diff --git a/app/src/main/java/org/levimc/launcher/core/curseforge/CurseForgeClient.java b/app/src/main/java/org/levimc/launcher/core/curseforge/CurseForgeClient.java
index 4e3a8dfa3..f87124ed0 100644
--- a/app/src/main/java/org/levimc/launcher/core/curseforge/CurseForgeClient.java
+++ b/app/src/main/java/org/levimc/launcher/core/curseforge/CurseForgeClient.java
@@ -50,6 +50,17 @@ public static synchronized CurseForgeClient getInstance() {
         return instance;
     }
 
+    private static IOException httpError(Response response) {
+        int code = response.code();
+        if (code == 401 || code == 403) {
+            String reason = API_KEY == null || API_KEY.isEmpty()
+                    ? "no CurseForge API key in this build (set curseforge.api_key in local.properties)"
+                    : "CurseForge rejected the API key";
+            return new IOException(reason + " (HTTP " + code + ")");
+        }
+        return new IOException("Unexpected code " + response);
+    }
+
     public interface CurseForgeCallback<T> {
         void onSuccess(T result);
         void onError(Throwable t);
@@ -88,7 +99,7 @@ public void onFailure(Call call, IOException e) {
             @Override
             public void onResponse(Call call, Response response) {
                 if (!response.isSuccessful()) {
-                    callback.onError(new IOException("Unexpected code " + response));
+                    callback.onError(httpError(response));
                     return;
                 }
                 
@@ -120,7 +131,7 @@ public void onFailure(Call call, IOException e) {
             @Override
             public void onResponse(Call call, Response response) throws IOException {
                 if (!response.isSuccessful()) {
-                    callback.onError(new IOException("Unexpected code " + response));
+                    callback.onError(httpError(response));
                     return;
                 }
 
@@ -155,7 +166,7 @@ public void onFailure(Call call, IOException e) {
             @Override
             public void onResponse(Call call, Response response) {
                 if (!response.isSuccessful()) {
-                    callback.onError(new IOException("Unexpected code " + response));
+                    callback.onError(httpError(response));
                     return;
                 }