diff --git a/gfd/i18n/__init__.py b/gfd/i18n/__init__.py
new file mode 100644
index 0000000..e032c49
--- /dev/null
+++ b/gfd/i18n/__init__.py
@@ -0,0 +1,18 @@
+import importlib
+
+class Translator:
+    def __init__(self, lang="en"):
+        self.translations = {}
+        self.load(lang)
+
+    def load(self, lang):
+        try:
+            mod = importlib.import_module(f"gfd.i18n.{lang}")
+            self.translations = getattr(mod, "translations", {})
+        except ModuleNotFoundError:
+            # fallback to Spanish
+            mod = importlib.import_module("gfd.i18n.es")
+            self.translations = getattr(mod, "translations", {})
+
+    def __call__(self, key):
+        return self.translations.get(key, key)
diff --git a/gfd/i18n/en.py b/gfd/i18n/en.py
new file mode 100644
index 0000000..3017bc8
--- /dev/null
+++ b/gfd/i18n/en.py
@@ -0,0 +1,4 @@
+translations = {
+    "hello_world": "Hello, World!",
+    "window_title": "Digital Signature Manager",
+}
diff --git a/gfd/i18n/es.py b/gfd/i18n/es.py
new file mode 100644
index 0000000..e57ed7a
--- /dev/null
+++ b/gfd/i18n/es.py
@@ -0,0 +1,4 @@
+translations = {
+    "hello_world": "¡Hola, Mundo!",
+    "window_title": "Gestor de Firma Digital",
+}
diff --git a/gfd/ui.py b/gfd/ui.py
new file mode 100644
index 0000000..a533607
--- /dev/null
+++ b/gfd/ui.py
@@ -0,0 +1,23 @@
+from PySide6 import QtWidgets, QtCore
+import gfd.i18n as i18n
+
+class GFDWidget(QtWidgets.QWidget):
+    def __init__(self, tr):
+        super().__init__()
+        self.tr = tr
+        self.setWindowTitle(self.tr("window_title"))
+        self.resize(300, 100)
+
+        label = QtWidgets.QLabel(self.tr("hello_world"), alignment=QtCore.Qt.AlignCenter)
+        lay = QtWidgets.QVBoxLayout(self)
+        lay.addWidget(label)
+
+def run(lang="es"):
+    import sys
+    app = QtWidgets.QApplication(sys.argv)
+
+    tr = i18n.Translator(lang)
+    w = GFDWidget(tr)
+    w.show()
+
+    sys.exit(app.exec())
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..66b3afe
--- /dev/null
+++ b/main.py
@@ -0,0 +1,4 @@
+import gfd.ui as w
+
+if __name__ == "__main__":
+    w.run("es")
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..91c79fa
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,4 @@
+PySide6==6.9.2
+PySide6_Addons==6.9.2
+PySide6_Essentials==6.9.2
+shiboken6==6.9.2