diff --git a/litellm/llms/chatgpt/realtime.py b/litellm/llms/chatgpt/realtime.py
index 27ce6cb3966..559a6ef18f6 100644
--- a/litellm/llms/chatgpt/realtime.py
+++ b/litellm/llms/chatgpt/realtime.py
@@ -5,7 +5,6 @@ from typing import TYPE_CHECKING, Final
 
 from httpx import URL, QueryParams
 from pydantic import TypeAdapter
-from websockets.exceptions import ConnectionClosed
 
 from litellm.constants import REALTIME_WEBSOCKET_MAX_MESSAGE_SIZE_BYTES
 from litellm.llms.openai.realtime.handler import OpenAIRealtime
@@ -114,6 +113,8 @@ class ChatGPTRealtime(OpenAIRealtime):
         )
 
     async def close_call(self, connection: "ClientConnection", model: str, api_base: str) -> None:
+        from websockets.exceptions import ConnectionClosed
+
         if realtime_endpoint(model) == "live":
             try:
                 await connection.send('{"type":"session.close"}')
@@ -124,7 +125,8 @@ class ChatGPTRealtime(OpenAIRealtime):
         await self.hangup_call(api_base)
 
     async def hangup_call(self, api_base: str) -> None:
-        from litellm.llms.custom_httpx.http_handler import AsyncHTTPHandler
+        from litellm.llms.custom_httpx.http_handler import get_async_httpx_client
+        from litellm.types.utils import LlmProviders
 
         base: Final = URL(api_base)
         url: Final = base.copy_with(
@@ -132,12 +134,9 @@ class ChatGPTRealtime(OpenAIRealtime):
             path=f"{base.path.rstrip('/')}/realtime/calls/{self._call_id}/hangup",
             params=tuple((key, value) for key, value in self._extra_query.items() if key not in ("model", "call_id")),
         )
-        client: Final = AsyncHTTPHandler()
-        try:
-            response: Final = await client.post(str(url), headers=self._profile_headers, data=b"", timeout=10)
-            response.raise_for_status()
-        finally:
-            await client.close()
+        client: Final = get_async_httpx_client(llm_provider=LlmProviders.CHATGPT)
+        response: Final = await client.post(str(url), headers=self._profile_headers, data=b"", timeout=10)
+        response.raise_for_status()
 
     @staticmethod
     def get_api_base(api_base: str | None = None) -> str:
@@ -182,7 +181,9 @@ class ChatGPTRealtime(OpenAIRealtime):
             base.copy_with(
                 scheme="wss" if base.scheme in ("https", "wss") else "ws",
                 path=f"{base.path.rstrip('/')}/{endpoint}",
-                params=query_params,
+                params=QueryParams(TypeAdapter(Mapping[str, str | None]).validate_python(query_params)).merge(
+                    tuple((key, value) for key, value in self._extra_query.items() if key not in ("model", "call_id"))
+                ),
             )
         )
 
diff --git a/litellm/llms/custom_httpx/llm_http_handler.py b/litellm/llms/custom_httpx/llm_http_handler.py
index 974f52b4268..44099efedeb 100644
--- a/litellm/llms/custom_httpx/llm_http_handler.py
+++ b/litellm/llms/custom_httpx/llm_http_handler.py
@@ -6330,6 +6330,9 @@ class BaseLLMHTTPHandler:
         Uses provider_config (BaseRealtimeHTTPConfig) for URL construction and
         header auth when available; falls back to the legacy OpenAI-style defaults.
         """
+        from litellm.llms.chatgpt.common_utils import without_oauth_identity_headers
+        from litellm.llms.chatgpt.realtime import ChatGPTRealtimeHTTPConfig
+
         if client is None or not isinstance(client, AsyncHTTPHandler):
             async_httpx_client = get_async_httpx_client(
                 llm_provider=litellm.LlmProviders.OPENAI,
@@ -6355,7 +6358,11 @@ class BaseLLMHTTPHandler:
             }
 
         if extra_headers:
-            headers.update(extra_headers)
+            headers.update(
+                without_oauth_identity_headers(extra_headers)
+                if isinstance(provider_config, ChatGPTRealtimeHTTPConfig)
+                else extra_headers
+            )
 
         logging_obj.pre_call(
             input=request_data,
diff --git a/litellm/proxy/realtime_endpoints/call_supervision.py b/litellm/proxy/realtime_endpoints/call_supervision.py
index e750ce61d6a..ae04582a36b 100644
--- a/litellm/proxy/realtime_endpoints/call_supervision.py
+++ b/litellm/proxy/realtime_endpoints/call_supervision.py
@@ -120,12 +120,19 @@ class CallSupervisor:
             try:
                 if not self._terminal:
                     deadline: Final = asyncio.get_running_loop().time() + self._termination_timeout
+                    primary_deadline: Final = (
+                        deadline - self._termination_timeout / 2
+                        if self._terminal_usage_required and self._force_close_call is not None
+                        else deadline
+                    )
                     try:
-                        await asyncio.wait_for(self._close_call(), timeout=self._termination_timeout)
+                        await asyncio.wait_for(
+                            self._close_call(), timeout=max(0.0, primary_deadline - asyncio.get_running_loop().time())
+                        )
                         self._close_confirmed = True
                     except Exception:  # noqa: BLE001  # provider exceptions can contain credentials
                         verbose_proxy_logger.error("Realtime observer could not terminate upstream call")
-                    await self._drain(reader, timeout=max(0.0, deadline - asyncio.get_running_loop().time()))
+                    await self._drain(reader, timeout=max(0.0, primary_deadline - asyncio.get_running_loop().time()))
                     if self._terminal_usage_required and not self._terminal and self._force_close_call is not None:
                         remaining: Final = max(0.0, deadline - asyncio.get_running_loop().time())
                         try:
diff --git a/tests/test_litellm/llms/chatgpt/test_realtime.py b/tests/test_litellm/llms/chatgpt/test_realtime.py
index 6db166e956b..b02b3a551f2 100644
--- a/tests/test_litellm/llms/chatgpt/test_realtime.py
+++ b/tests/test_litellm/llms/chatgpt/test_realtime.py
@@ -1,4 +1,5 @@
 import json
+import sys
 from contextlib import nullcontext
 from types import SimpleNamespace
 from unittest.mock import AsyncMock, patch
@@ -14,13 +15,14 @@ from litellm.types.router import GenericLiteLLMParams
 
 @pytest.mark.asyncio
 @pytest.mark.parametrize("failure", ["closed", "network"])
-@pytest.mark.parametrize(
-    "hangup_status, expectation", [(200, nullcontext()), (503, pytest.raises(httpx.HTTPStatusError))]
-)
-async def test_live_closed_observer_uses_independent_hangup(failure, hangup_status, expectation, chatgpt_tokens):
+@pytest.mark.parametrize("hangup_status", [200, 503])
+async def test_live_closed_observer_uses_independent_hangup(failure, hangup_status, chatgpt_tokens, monkeypatch):
     from websockets.exceptions import ConnectionClosedOK
     from websockets.frames import Close
 
+    from litellm.caching.llm_caching_handler import LLMClientCache
+
+    monkeypatch.setattr(litellm, "in_memory_llm_clients_cache", LLMClientCache())
     handler = ChatGPTRealtime(
         GenericLiteLLMParams(
             chatgpt_realtime_call_id="rtc_live_closed",
@@ -46,15 +48,21 @@ async def test_live_closed_observer_uses_independent_hangup(failure, hangup_stat
         return httpx.Response(hangup_status)
 
     client = httpx.AsyncClient(transport=httpx.MockTransport(respond))
-    with patch("httpx.AsyncClient", return_value=client):
-        with expectation:
-            await handler.close_call(connection, "gpt-live-1-codex", "https://gateway.example/v1")
-    assert len(requests) == 1
+    try:
+        with patch("httpx.AsyncClient", return_value=client) as create_client:
+            for _ in range(2):
+                with pytest.raises(httpx.HTTPStatusError) if hangup_status == 503 else nullcontext():
+                    await handler.close_call(connection, "gpt-live-1-codex", "https://gateway.example/v1")
+                assert not client.is_closed
+            create_client.assert_called_once()
+    finally:
+        await client.aclose()
+    assert len(requests) == 2
     assert requests[0].method == "POST"
     assert str(requests[0].url) == "https://gateway.example/v1/realtime/calls/rtc_live_closed/hangup?gateway=tenant"
     assert requests[0].headers["x-gateway-token"] == "test-only"
     assert requests[0].headers["Authorization"] == "Bearer test-token-default"
-    assert client.is_closed
+    assert requests[0].extensions["timeout"]["read"] == 10
 
 
 @pytest.mark.asyncio
@@ -305,6 +313,63 @@ def test_realtime_uses_platform_endpoint_with_oauth_headers(model, endpoint, cha
     assert headers["openai-alpha"] == "quicksilver=v2"
 
 
+@pytest.mark.parametrize("endpoint", ["live", "realtime"])
+def test_new_realtime_session_preserves_gateway_query(endpoint, chatgpt_tokens, local_model_cost_map):
+    model = "gpt-live-1-codex" if endpoint == "live" else "gpt-realtime-1.5"
+    handler = ChatGPTRealtime(
+        GenericLiteLLMParams(
+            chatgpt_token_dir=chatgpt_tokens,
+            chatgpt_realtime_client_query={"intent": "conversation", "architecture": "client-architecture"},
+            extra_query={
+                "gateway_token": "opaque +/& value",
+                "intent": "gateway-intent",
+                "architecture": "gateway-architecture",
+                "model": "other-model",
+                "call_id": "rtc_other",
+            },
+        ),
+        {},
+    )
+    url = httpx.URL(handler._construct_url("https://gateway.example/v1", {"model": model, "intent": "query-intent"}))
+    assert url.path == f"/v1/{endpoint}"
+    assert dict(url.params) == {
+        "model": model,
+        "gateway_token": "opaque +/& value",
+        "intent": "gateway-intent",
+        "architecture": "gateway-architecture",
+    }
+
+
+@pytest.mark.asyncio
+async def test_openai_http_call_does_not_require_websockets(monkeypatch):
+    monkeypatch.delitem(sys.modules, "litellm.llms.chatgpt.realtime", raising=False)
+    for name in tuple(sys.modules):
+        if name == "websockets" or name.startswith("websockets."):
+            monkeypatch.delitem(sys.modules, name)
+    monkeypatch.setitem(sys.modules, "websockets", None)
+    requests = []
+
+    def respond(request):
+        requests.append(request)
+        return httpx.Response(201, text="v=0\r\n")
+
+    client = AsyncHTTPHandler()
+    client.client = httpx.AsyncClient(transport=httpx.MockTransport(respond))
+    try:
+        response = await litellm.arealtime_calls(
+            model="openai/gpt-realtime-1.5",
+            openai_ephemeral_key="test-only",
+            sdp_body=b"v=0\r\n",
+            api_key="test-only",
+            client=client,
+        )
+        assert response.status_code == 201
+        assert len(requests) == 1
+        assert requests[0].url.path == "/v1/realtime/calls"
+    finally:
+        await client.client.aclose()
+
+
 @pytest.mark.parametrize("endpoint", ["live", "realtime"])
 @pytest.mark.parametrize("call_id", [None, "rtc_metadata"])
 def test_realtime_routes_new_models_using_registered_metadata(endpoint, call_id, chatgpt_tokens, local_model_cost_map):
diff --git a/tests/test_litellm/llms/custom_httpx/test_llm_http_handler.py b/tests/test_litellm/llms/custom_httpx/test_llm_http_handler.py
index cea2d439198..29a58b788f0 100644
--- a/tests/test_litellm/llms/custom_httpx/test_llm_http_handler.py
+++ b/tests/test_litellm/llms/custom_httpx/test_llm_http_handler.py
@@ -3620,3 +3620,62 @@ def test_image_edit_handler_keeps_the_sync_transform():
     assert config.transform_calls == ["sync"]
     assert captured["body"] == {"transformed_by": "sync"}
     assert response.data[0].b64_json == "sync"
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("endpoint", ["client_secrets", "transcription_sessions"])
+@pytest.mark.parametrize("provider", ["chatgpt", "openai"])
+@pytest.mark.parametrize("authorization_header", ["Authorization", "aUtHoRiZaTiOn"])
+async def test_realtime_http_sessions_preserve_provider_identity(
+    endpoint, provider, authorization_header, tmp_path, monkeypatch
+):
+    import time
+
+    from litellm.llms.chatgpt.realtime import ChatGPTRealtimeHTTPConfig
+    from litellm.llms.openai.realtime.http_transformation import OpenAIRealtimeHTTPConfig
+    from litellm.types.router import GenericLiteLLMParams
+
+    monkeypatch.setenv("CHATGPT_TOKEN_DIR", str(tmp_path))
+    monkeypatch.setenv("CHATGPT_AUTH_FILE", "auth.json")
+    (tmp_path / "auth.json").write_text(
+        json.dumps({"access_token": "test-resolved", "account_id": "test-selected", "expires_at": time.time() + 3600})
+    )
+    config = ChatGPTRealtimeHTTPConfig(GenericLiteLLMParams()) if provider == "chatgpt" else OpenAIRealtimeHTTPConfig()
+    requests = []
+
+    def respond(request):
+        requests.append(request)
+        return httpx.Response(200, json={"id": "session-test"})
+
+    client = AsyncHTTPHandler()
+    client.client = httpx.AsyncClient(transport=httpx.MockTransport(respond))
+    try:
+        response = await BaseLLMHTTPHandler()._async_realtime_session_post(
+            endpoint=endpoint,
+            api_base="https://gateway.example/v1",
+            api_key="test-openai",
+            request_data={"session": {"model": "gpt-realtime-1.5"}},
+            logging_obj=Mock(),
+            timeout=5,
+            provider_config=config,
+            model="gpt-realtime-1.5",
+            extra_headers={
+                authorization_header: "Bearer test-override",
+                "CHATGPT-ACCOUNT-ID": "test-other-account",
+                "x-gateway-route": "required",
+            },
+            client=client,
+        )
+        assert response.status_code == 200
+        assert not client.client.is_closed
+    finally:
+        await client.client.aclose()
+    assert len(requests) == 1
+    assert requests[0].url.path == f"/v1/realtime/{endpoint}"
+    assert requests[0].headers["x-gateway-route"] == "required"
+    if provider == "chatgpt":
+        assert requests[0].headers.get_list("authorization") == ["Bearer test-resolved"]
+        assert requests[0].headers.get_list("chatgpt-account-id") == ["test-selected"]
+    else:
+        assert requests[0].headers.get_list("authorization")[-1] == "Bearer test-override"
+        assert requests[0].headers["chatgpt-account-id"] == "test-other-account"
diff --git a/tests/test_litellm/proxy/realtime_endpoints/test_call_supervision.py b/tests/test_litellm/proxy/realtime_endpoints/test_call_supervision.py
index 7d0d614f31d..c14597a012a 100644
--- a/tests/test_litellm/proxy/realtime_endpoints/test_call_supervision.py
+++ b/tests/test_litellm/proxy/realtime_endpoints/test_call_supervision.py
@@ -30,6 +30,47 @@ class Socket:
         self.closed = True
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize("stalled_step", ["close", "drain"])
+async def test_live_initial_close_reserves_time_for_independent_hangup(stalled_step):
+    socket = Socket()
+    logger = MagicMock(spec=Logging)
+    logger.model_call_details = {}
+    close_cancelled = asyncio.Event()
+
+    async def close():
+        if stalled_step == "close":
+            try:
+                await asyncio.Event().wait()
+            finally:
+                close_cancelled.set()
+
+    async def force_close():
+        await socket.messages.put({"type": "session.closed", "usage": {"audio_duration_ms": 1000}})
+
+    force = AsyncMock(side_effect=force_close)
+    sink = Sink(logger)
+    supervisor = CallSupervisor(
+        socket,
+        sink,
+        logger,
+        UserAPIKeyAuth(),
+        close,
+        force_close_call=force,
+        drain_timeout=1,
+        termination_timeout=0.08,
+    )
+    await socket.messages.put({"type": "session.started"})
+    await supervisor.start()
+    await asyncio.wait_for(supervisor.close(), timeout=0.5)
+    force.assert_awaited_once()
+    assert close_cancelled.is_set() == (stalled_step == "close")
+    assert any(event["type"] == "session.closed" for event in sink.events)
+    assert not logger.model_call_details.get("realtime_usage_incomplete")
+    assert sink.logs == 1
+    assert socket.closed
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize("fallback", ["terminal", "no_terminal", "timeout"])
 async def test_live_unacknowledged_close_uses_bounded_independent_hangup(monkeypatch, fallback):