f

demo/_gradio_compat.py

@@ -0,0 +1,53 @@
+"""
+_gradio_compat.py
+-----------------
+Work around a known gradio_client bug that crashes the demo's API-info /
+schema endpoint:
+
+    TypeError: argument of type 'bool' is not iterable
+    ... gradio_client/utils.py, get_type: `if "const" in schema`
+
+It triggers when a component's JSON schema contains a boolean
+`additionalProperties` (gr.Chatbot(type="messages") + gr.State produce one).
+gradio_client recurses into that bool and treats it as a dict.
+
+Importing this module patches the two offending functions to short-circuit on
+bool schemas, returning "Any". Safe across gradio 4.x / 5.x — it only adds a
+guard before the original logic runs.
+
+Usage: `import demo._gradio_compat  # noqa: F401` BEFORE building/launching the
+Blocks app (already done in demo/app.py).
+"""
+
+def _apply():
+    try:
+        import gradio_client.utils as gcu
+    except Exception:
+        return  # gradio_client not importable — nothing to patch.
+
+    # Guard _json_schema_to_python_type against bool schemas.
+    if not getattr(gcu, "_cxr_patched_js", False):
+        _orig_js = gcu._json_schema_to_python_type
+
+        def _json_schema_to_python_type(schema, defs=None):
+            if isinstance(schema, bool):
+                return "Any"
+            return _orig_js(schema, defs)
+
+        gcu._json_schema_to_python_type = _json_schema_to_python_type
+        gcu._cxr_patched_js = True
+
+    # Guard get_type against non-dict schemas (the actual crash site).
+    if not getattr(gcu, "_cxr_patched_gt", False):
+        _orig_gt = gcu.get_type
+
+        def get_type(schema):
+            if not isinstance(schema, dict):
+                return "Any"
+            return _orig_gt(schema)
+
+        gcu.get_type = get_type
+        gcu._cxr_patched_gt = True
+
+
+_apply()

demo/app.py

@@ -98,6 +98,7 @@ def resolve_checkpoint(args) -> str:
 
 
 def build_ui(bot: CXRChatbot, max_new_tokens: int):
+    import demo._gradio_compat  # noqa: F401  (fix gradio_client schema crash)
     import gradio as gr
 
     with gr.Blocks(title="CXR-HIEU Demo", theme=gr.themes.Soft()) as demo: