fix(api): keep the base path of the server URL in Twirp requests

livekit-api/livekit/api/twirp_client.py

@@ -202,7 +202,7 @@ def __init__(
         if scheme.startswith("ws"):
             scheme = scheme.replace("ws", "http")
 
-        host = f"{scheme}://{parse_res.netloc}/{parse_res.path}"
+        host = f"{scheme}://{parse_res.netloc}{parse_res.path}"
         self.host = host.rstrip("/")
         self.pkg = pkg
         self.prefix = prefix
@@ -248,10 +248,13 @@ async def request(
         attempted = {host_key(self._origin)}
         region_origins: Optional[List[str]] = None
         current_origin = self._origin
+        # The configured host may carry a base path (e.g. behind a reverse
+        # proxy); fallback regions are bare origins.
+        current_base = self.host
 
         for attempt in range(max_attempts):
             is_last = attempt + 1 >= max_attempts
-            url = f"{current_origin}/{path}"
+            url = f"{current_base}/{path}"
 
             transport_exc: Optional[BaseException] = None
             retryable_status: Optional[int] = None
@@ -298,6 +301,7 @@ async def request(
             await asyncio.sleep(self._failover_backoff * (2**attempt))
             attempted.add(host_key(next_origin))
             current_origin = next_origin
+            current_base = next_origin
 
         raise RuntimeError("failover loop exited without returning")  # unreachable
 

tests/api/test_twirp_client.py

@@ -0,0 +1,69 @@
+# Copyright 2026 LiveKit, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import asyncio
+from typing import List
+
+import pytest
+
+from livekit.api.twirp_client import TwirpClient
+from livekit.protocol.room import ListRoomsRequest, ListRoomsResponse
+
+
+class _Response:
+    status = 200
+
+    async def read(self) -> bytes:
+        return ListRoomsResponse().SerializeToString()
+
+
+class _Post:
+    async def __aenter__(self) -> _Response:
+        return _Response()
+
+    async def __aexit__(self, *exc) -> None:
+        return None
+
+
+class _RecordingSession:
+    timeout = None
+
+    def __init__(self) -> None:
+        self.urls: List[str] = []
+
+    def post(self, url: str, **kwargs) -> _Post:
+        self.urls.append(url)
+        return _Post()
+
+
+def _requested_url(host: str) -> str:
+    session = _RecordingSession()
+    client = TwirpClient(session, host, "livekit")  # type: ignore[arg-type]
+    asyncio.run(
+        client.request("RoomService", "ListRooms", ListRoomsRequest(), {}, ListRoomsResponse)
+    )
+    return session.urls[0]
+
+
+@pytest.mark.parametrize(
+    ("host", "expected"),
+    [
+        ("wss://example.livekit.cloud", "https://example.livekit.cloud"),
+        ("http://localhost:7880/", "http://localhost:7880"),
+        ("https://proxy.example.com/livekit", "https://proxy.example.com/livekit"),
+        ("wss://proxy.example.com/livekit/", "https://proxy.example.com/livekit"),
+    ],
+)
+def test_request_url_keeps_the_base_path(host: str, expected: str) -> None:
+    assert _requested_url(host) == f"{expected}/twirp/livekit.RoomService/ListRooms"