Call mounted gradio app via api (#4435)

* Fix bug

* Add changelog

client/python/CHANGELOG.md

@@ -5,6 +5,7 @@
 ## Bug Fixes:
 - Fixes parameter names not showing underscores by [@abidlabs](https://github.com/abidlabs) in [PR 4230](https://github.com/gradio-app/gradio/pull/4230)
 - Fixes issue in which state was not handled correctly if `serialize=False` by [@abidlabs](https://github.com/abidlabs) in [PR 4230](https://github.com/gradio-app/gradio/pull/4230)
+- Fixed bug where mounted apps could not be called via the client by [@freddyaboulton](https://github.com/freddyaboulton) in [PR 4435](https://github.com/gradio-app/gradio/pull/4435)
 
 ## Breaking Changes:
 

client/python/gradio_client/client.py

@@ -85,7 +85,7 @@ class Client:
         self.space_id = None
 
         if src.startswith("http://") or src.startswith("https://"):
-            _src = src
+            _src = src if src.endswith("/") else src + "/"
         else:
             _src = self._space_name_to_src(src)
             if _src is None:

client/python/gradio_client/utils.py

@@ -23,14 +23,14 @@ import requests
 from huggingface_hub import SpaceStage
 from websockets.legacy.protocol import WebSocketCommonProtocol
 
-API_URL = "/api/predict/"
-WS_URL = "/queue/join"
-UPLOAD_URL = "/upload"
-CONFIG_URL = "/config"
-API_INFO_URL = "/info"
-RAW_API_INFO_URL = "/info?serialize=False"
+API_URL = "api/predict/"
+WS_URL = "queue/join"
+UPLOAD_URL = "upload"
+CONFIG_URL = "config"
+API_INFO_URL = "info"
+RAW_API_INFO_URL = "info?serialize=False"
 SPACE_FETCHER_URL = "https://gradio-space-api-fetcher-v2.hf.space/api"
-RESET_URL = "/reset"
+RESET_URL = "reset"
 SPACE_URL = "https://hf.space/{}"
 
 STATE_COMPONENT = "state"

client/python/test/test_client.py

@@ -11,6 +11,9 @@ from unittest.mock import MagicMock, patch
 
 import gradio as gr
 import pytest
+import uvicorn
+from fastapi import FastAPI
+from gradio.networking import Server
 from huggingface_hub.utils import RepositoryNotFoundError
 
 from gradio_client import Client
@@ -319,6 +322,37 @@ class TestClientPredictions:
             ret = client.predict(message, initial_history, api_name="/submit")
             assert ret == ("", [["", None], ["Hello", "I love you"]])
 
+    def test_can_call_mounted_app_via_api(self):
+        def greet(name):
+            return "Hello " + name + "!"
+
+        gradio_app = gr.Interface(
+            fn=greet,
+            inputs=gr.Textbox(lines=2, placeholder="Name Here..."),
+            outputs="text",
+        )
+
+        app = FastAPI()
+        app = gr.mount_gradio_app(app, gradio_app, path="/test/gradio")
+        config = uvicorn.Config(
+            app=app,
+            port=8000,
+            log_level="info",
+        )
+        server = Server(config=config)
+        # Using the gradio Server class to not have
+        # to implement code again to run uvicorn in a separate thread
+        # However, that means we need to set this flag to prevent
+        # run_in_thread_from_blocking
+        server.started = True
+        try:
+            server.run_in_thread()
+            time.sleep(1)
+            client = Client("http://127.0.0.1:8000/test/gradio/")
+            assert client.predict("freddy") == "Hello freddy!"
+        finally:
+            server.thread.join(timeout=1)
+
 
 class TestStatusUpdates:
     @patch("gradio_client.client.Endpoint.make_end_to_end_fn")