Gradio MVP launcher works both locally and on Hugging Face Spaces

app.py

@@ -1,5 +1,6 @@
 """Hugging Face Spaces launcher for the GCMD classifier MVP."""
 
+import os
 import sys
 from pathlib import Path
 
@@ -11,5 +12,27 @@ from gcmd_classifier.ui.gradio_app import GRADIO_CSS, create_demo  # noqa: E402
 
 demo = create_demo()
 
+
+def gradio_server_name() -> str:
+    """Return the configured Gradio bind host for local and Spaces runtime."""
+    return os.environ.get("GRADIO_SERVER_NAME", "0.0.0.0")
+
+
+def gradio_server_port() -> int:
+    """Return the configured Gradio bind port for local and Spaces runtime."""
+    return int(os.environ.get("GRADIO_SERVER_PORT", "7860"))
+
+
+def launch() -> None:
+    """Launch the Gradio demo with Hugging Face compatible server settings."""
+    demo.queue().launch(
+        css=GRADIO_CSS,
+        server_name=gradio_server_name(),
+        server_port=gradio_server_port(),
+        share=False,
+        prevent_thread_lock=False,
+    )
+
+
 if __name__ == "__main__":
-    demo.launch(css=GRADIO_CSS)
+    launch()

tests/test_ui.py

@@ -53,6 +53,11 @@ class FakeLayout:
 
 class FakeBlocks(FakeLayout):
     launched = 0
+    queued = 0
+
+    def queue(self):
+        type(self).queued += 1
+        return self
 
     def launch(self, **kwargs: Any) -> None:
         self.launch_kwargs = kwargs
@@ -168,6 +173,7 @@ def test_ui_module_does_not_classify_or_call_model_at_import_time(monkeypatch) -
 
 def test_root_app_imports_without_launching_server(monkeypatch) -> None:
     FakeBlocks.launched = 0
+    FakeBlocks.queued = 0
     monkeypatch.setitem(sys.modules, "gradio", _fake_gradio_module())
     sys.modules.pop("app", None)
 
@@ -175,6 +181,40 @@ def test_root_app_imports_without_launching_server(monkeypatch) -> None:
 
     assert isinstance(module.demo, FakeBlocks)
     assert FakeBlocks.launched == 0
+    assert FakeBlocks.queued == 0
+
+
+def test_root_app_launch_uses_spaces_compatible_settings(monkeypatch) -> None:
+    FakeBlocks.launched = 0
+    FakeBlocks.queued = 0
+    monkeypatch.setitem(sys.modules, "gradio", _fake_gradio_module())
+    monkeypatch.setenv("GRADIO_SERVER_NAME", "127.0.0.1")
+    monkeypatch.setenv("GRADIO_SERVER_PORT", "9999")
+    sys.modules.pop("app", None)
+    module = importlib.import_module("app")
+
+    module.launch()
+
+    assert FakeBlocks.queued == 1
+    assert FakeBlocks.launched == 1
+    assert module.demo.launch_kwargs == {
+        "css": module.GRADIO_CSS,
+        "server_name": "127.0.0.1",
+        "server_port": 9999,
+        "share": False,
+        "prevent_thread_lock": False,
+    }
+
+
+def test_root_app_uses_spaces_default_server_settings(monkeypatch) -> None:
+    monkeypatch.setitem(sys.modules, "gradio", _fake_gradio_module())
+    monkeypatch.delenv("GRADIO_SERVER_NAME", raising=False)
+    monkeypatch.delenv("GRADIO_SERVER_PORT", raising=False)
+    sys.modules.pop("app", None)
+    module = importlib.import_module("app")
+
+    assert module.gradio_server_name() == "0.0.0.0"
+    assert module.gradio_server_port() == 7860
 
 
 def test_root_app_is_thin_launcher_without_classification_logic() -> None:
@@ -184,7 +224,11 @@ def test_root_app_is_thin_launcher_without_classification_logic() -> None:
     assert "classify_article" not in text
     assert "route_topics" not in text
     assert "OpenAI" not in text
-    assert "demo.launch(css=GRADIO_CSS)" in text
+    assert "demo.queue().launch" in text
+    assert "server_name=gradio_server_name()" in text
+    assert "server_port=gradio_server_port()" in text
+    assert "share=False" in text
+    assert "prevent_thread_lock=False" in text
 
 
 def test_ui_calls_pipeline_service(monkeypatch) -> None: