diff --git a/extension/duohacker-extension.zip b/extension/duohacker-extension.zip
new file mode 100644
index 0000000..1f83ee1
Binary files /dev/null and b/extension/duohacker-extension.zip differ
diff --git a/extension/source/content.js b/extension/source/content.js
new file mode 100644
index 0000000..5e4d540
--- /dev/null
+++ b/extension/source/content.js
@@ -0,0 +1,10 @@
+const script = document.createElement('script');
+
+script.src = chrome.runtime.getURL('inject.js');
+
+script.onload = () => script.remove();
+
+(document.head || document.documentElement)
+  .appendChild(script);
+
+console.log('[DuoHacker] loader injected');
\ No newline at end of file
diff --git a/extension/source/icon.png b/extension/source/icon.png
new file mode 100644
index 0000000..5552aec
Binary files /dev/null and b/extension/source/icon.png differ
diff --git a/extension/source/inject.js b/extension/source/inject.js
new file mode 100644
index 0000000..3e3c55e
--- /dev/null
+++ b/extension/source/inject.js
@@ -0,0 +1,298 @@
+(async () => {
+
+(() => {
+
+  const prefix = 'usc:Duolingo_DuoHacker:';
+
+  const listeners = new Map();
+
+  let listenerSeq = 0;
+
+  function read(name, fallback) {
+
+    const raw = localStorage.getItem(prefix + name);
+
+    if (raw === null) return fallback;
+
+    try {
+      return JSON.parse(raw);
+    } catch {
+      return raw;
+    }
+  }
+
+  function write(name, value) {
+
+    const oldValue = read(name);
+
+    localStorage.setItem(
+      prefix + name,
+      JSON.stringify(value)
+    );
+
+    for (const listener of listeners.values()) {
+
+      if (listener.name === name) {
+
+        listener.callback(
+          name,
+          oldValue,
+          value,
+          false
+        );
+      }
+    }
+  }
+
+  function GM_xmlhttpRequest(details) {
+
+    const controller = new AbortController();
+
+    const promise = fetch(details.url, {
+
+      method: details.method || 'GET',
+
+      headers: details.headers,
+
+      body: details.data,
+
+      signal: controller.signal,
+
+      credentials:
+        details.anonymous
+          ? 'omit'
+          : 'include'
+
+    })
+
+    .then(async response => {
+
+      const responseText =
+
+        details.responseType === 'blob' ||
+        details.responseType === 'arraybuffer'
+
+          ? ''
+
+          : await response.clone().text();
+
+      const body =
+
+        details.responseType === 'blob'
+
+          ? await response.blob()
+
+          : details.responseType === 'arraybuffer'
+
+          ? await response.arrayBuffer()
+
+          : details.responseType === 'json'
+
+          ? JSON.parse(responseText || 'null')
+
+          : responseText;
+
+      const xhr = {
+
+        response: body,
+
+        responseText,
+
+        status: response.status,
+
+        statusText: response.statusText,
+
+        finalUrl: response.url
+
+      };
+
+      details.onload?.(xhr);
+
+      return xhr;
+
+    })
+
+    .catch(error => {
+
+      details.onerror?.(error);
+
+      throw error;
+
+    });
+
+    return {
+
+      abort: () => controller.abort(),
+
+      then: promise.then.bind(promise),
+
+      catch: promise.catch.bind(promise),
+
+      finally: promise.finally.bind(promise)
+
+    };
+  }
+
+  function GM_addStyle(css) {
+
+    const style = document.createElement('style');
+
+    style.textContent = css;
+
+    document.head.appendChild(style);
+
+    return style;
+  }
+
+  const GM_info = {
+
+    script: {
+
+      name: 'Duolingo DuoHacker',
+
+      description:
+        'The #1 Duolingo hack',
+
+      version: '2026.05.25'
+
+    },
+
+    scriptHandler:
+      'Chrome Extension Harness',
+
+    version: '3.0'
+
+  };
+
+  const GM = {
+
+    info: GM_info,
+
+    getValue: (name, fallback) =>
+      Promise.resolve(read(name, fallback)),
+
+    setValue: (name, value) =>
+      Promise.resolve(write(name, value)),
+
+    deleteValue: name =>
+      Promise.resolve(
+        localStorage.removeItem(prefix + name)
+      ),
+
+    listValues: () =>
+      Promise.resolve(
+        Object.keys(localStorage)
+
+          .filter(key =>
+            key.startsWith(prefix)
+          )
+
+          .map(key =>
+            key.slice(prefix.length)
+          )
+      ),
+
+    addValueChangeListener:
+      (name, callback) => {
+
+        const id = ++listenerSeq;
+
+        listeners.set(id, {
+          name,
+          callback
+        });
+
+        return id;
+      },
+
+    removeValueChangeListener:
+      id => listeners.delete(id),
+
+    addStyle: GM_addStyle,
+
+    xmlHttpRequest: details =>
+      Promise.resolve(
+        GM_xmlhttpRequest(details)
+      ),
+
+    xmlhttpRequest: details =>
+      Promise.resolve(
+        GM_xmlhttpRequest(details)
+      ),
+
+    registerMenuCommand:
+      () => undefined,
+
+    setClipboard: text =>
+      navigator.clipboard.writeText(
+        String(text || '')
+      )
+  };
+
+  Object.assign(window, {
+
+    GM,
+
+    GM_info,
+
+    GM_getValue: read,
+
+    GM_setValue: write,
+
+    GM_deleteValue: name =>
+      localStorage.removeItem(prefix + name),
+
+    GM_listValues: () =>
+
+      Object.keys(localStorage)
+
+        .filter(key =>
+          key.startsWith(prefix)
+        )
+
+        .map(key =>
+          key.slice(prefix.length)
+        ),
+
+    GM_addValueChangeListener:
+      GM.addValueChangeListener,
+
+    GM_removeValueChangeListener:
+      GM.removeValueChangeListener,
+
+    GM_addStyle,
+
+    GM_xmlhttpRequest,
+
+    GM_registerMenuCommand:
+      () => undefined,
+
+    unsafeWindow: window
+
+  });
+
+})();
+
+try {
+
+  const res = await fetch(
+    'https://raw.githubusercontent.com/not2pixel/DuoHacker/main/v2/duohacker-v2.user.js'
+  );
+
+  const code = await res.text();
+
+  eval(code);
+
+  console.log(
+    '[DuoHacker] injected successfully'
+  );
+
+} catch (err) {
+
+  console.error(
+    '[DuoHacker] injection failed:',
+    err
+  );
+}
+
+})();
\ No newline at end of file
diff --git a/extension/source/manifest.json b/extension/source/manifest.json
new file mode 100644
index 0000000..e8be3a1
--- /dev/null
+++ b/extension/source/manifest.json
@@ -0,0 +1,62 @@
+{
+  "manifest_version": 3,
+
+  "name": "Duolingo DuoHacker v2",
+
+  "version": "1.0",
+
+  "description": "Duolingo DuoHacker — Browser Extension",
+
+  "icons": {
+    "128": "icon.png"
+  },
+
+  "content_scripts": [
+    {
+      "matches": [
+        "https://*.duolingo.com/*",
+        "https://*.duolingo.cn/*"
+      ],
+
+      "js": [
+        "content.js"
+      ],
+
+      "run_at": "document_end"
+    }
+  ],
+
+  "host_permissions": [
+    "https://*.duolingo.com/*",
+    "https://*.duolingo.cn/*",
+
+    "https://raw.githubusercontent.com/*",
+
+    "https://avatars.githubusercontent.com/*",
+
+    "https://fonts.googleapis.com/*",
+
+    "https://greasyfork.org/*",
+
+    "https://api.twisk.fun/*",
+
+    "https://stories.duolingo.com/*",
+
+    "https://goals-api.duolingo.com/*",
+
+    "https://duolingo-leaderboards-prod.duolingo.com/*"
+  ],
+
+  "web_accessible_resources": [
+    {
+      "resources": [
+        "inject.js"
+      ],
+
+      "matches": [
+        "https://*.duolingo.com/*",
+        "https://*.duolingo.cn/*"
+      ]
+    }
+  ]
+}