diff --git a/litellm/realtime_api/main.py b/litellm/realtime_api/main.py
index e88f52b91f9..046665c8f18 100644
--- a/litellm/realtime_api/main.py
+++ b/litellm/realtime_api/main.py
@@ -356,9 +356,15 @@ async def _arealtime(
             query_params=query_params,
         )
     elif _custom_llm_provider == "azure":
-        api_base = dynamic_api_base or litellm_params.api_base or litellm.api_base or get_secret_str("AZURE_API_BASE")
+        api_base = (
+            dynamic_api_base
+            or api_base
+            or litellm_params.api_base
+            or litellm.api_base
+            or get_secret_str("AZURE_API_BASE")
+        )
         # set API KEY
-        api_key = dynamic_api_key or litellm.api_key or litellm.openai_key or get_secret_str("AZURE_API_KEY")
+        api_key = dynamic_api_key or api_key or litellm.api_key or litellm.openai_key or get_secret_str("AZURE_API_KEY")
 
         api_version = api_version or litellm_params.api_version or "2024-10-01-preview"
 
@@ -386,9 +392,13 @@ async def _arealtime(
             litellm_metadata=_build_litellm_metadata(kwargs),
         )
     elif _custom_llm_provider == "openai":
-        api_base = dynamic_api_base or litellm_params.api_base or litellm.api_base or "https://api.openai.com/"
+        api_base = (
+            dynamic_api_base or api_base or litellm_params.api_base or litellm.api_base or "https://api.openai.com/"
+        )
         # set API KEY
-        api_key = dynamic_api_key or litellm.api_key or litellm.openai_key or get_secret_str("OPENAI_API_KEY")
+        api_key = (
+            dynamic_api_key or api_key or litellm.api_key or litellm.openai_key or get_secret_str("OPENAI_API_KEY")
+        )
 
         await openai_realtime.async_realtime(
             model=model,
@@ -590,4 +600,4 @@ async def _realtime_health_check(
         max_size=REALTIME_WEBSOCKET_MAX_MESSAGE_SIZE_BYTES,
         ssl=ssl_context,
     ):
-        return True
+        return True
\ No newline at end of file
diff --git a/tests/test_litellm/realtime_api/test_main.py b/tests/test_litellm/realtime_api/test_main.py
index 406f5ef56d9..2c6efa20f5e 100644
--- a/tests/test_litellm/realtime_api/test_main.py
+++ b/tests/test_litellm/realtime_api/test_main.py
@@ -103,3 +103,51 @@ def test_client_secret_forwards_nested_transcription_model_untouched(monkeypatch
     session = captured["request_data"]["session"]
     assert session["model"] == "gpt-4o-realtime-preview"
     assert session["input_audio_transcription"]["model"] == "whisper-1"
+
+
+def _run_arealtime(monkeypatch, provider, **kwargs):
+    captured = {}
+
+    async def mock_async_realtime(**call_kwargs):
+        captured.update(call_kwargs)
+
+    def mock_get_llm_provider(model, api_base, api_key):
+        return model, provider, None, None
+
+    monkeypatch.setattr(realtime_main, "get_llm_provider", mock_get_llm_provider)
+    handler = realtime_main.openai_realtime if provider == "openai" else realtime_main.azure_realtime
+    monkeypatch.setattr(handler, "async_realtime", mock_async_realtime)
+
+    asyncio.run(
+        realtime_main._arealtime.__wrapped__(
+            model="gpt-4o-realtime-preview",
+            websocket=object(),
+            litellm_logging_obj=FakeLogging(),
+            **kwargs,
+        )
+    )
+    return captured
+
+
+def test_openai_realtime_uses_explicit_api_key(monkeypatch):
+    """A key resolved from litellm_credential_name arrives as the explicit
+    api_key argument and must not be discarded."""
+    monkeypatch.delenv("OPENAI_API_KEY", raising=False)
+    monkeypatch.setattr(realtime_main.litellm, "api_key", None)
+    monkeypatch.setattr(realtime_main.litellm, "openai_key", None)
+
+    captured = _run_arealtime(monkeypatch, "openai", api_key="sk-from-credential", api_base="http://localhost:8799")
+    assert captured["api_key"] == "sk-from-credential"
+    assert captured["api_base"] == "http://localhost:8799"
+
+
+def test_azure_realtime_uses_explicit_api_key(monkeypatch):
+    monkeypatch.delenv("AZURE_API_KEY", raising=False)
+    monkeypatch.delenv("AZURE_API_BASE", raising=False)
+    monkeypatch.setattr(realtime_main.litellm, "api_key", None)
+    monkeypatch.setattr(realtime_main.litellm, "openai_key", None)
+
+    captured = _run_arealtime(
+        monkeypatch, "azure", api_key="azure-from-credential", api_base="https://my-azure.openai.azure.com"
+    )
+    assert captured["api_key"] == "azure-from-credential"
\ No newline at end of file