diff --git a/litellm/llms/hosted_vllm/embedding/transformation.py b/litellm/llms/hosted_vllm/embedding/transformation.py
index 9c3e8c6c7cc..4407e3b1b68 100644
--- a/litellm/llms/hosted_vllm/embedding/transformation.py
+++ b/litellm/llms/hosted_vllm/embedding/transformation.py
@@ -110,10 +110,13 @@ class HostedVLLMEmbeddingConfig(BaseEmbeddingConfig):
         if model.startswith("hosted_vllm/"):
             model = model.replace("hosted_vllm/", "", 1)
 
+        # Filter out None values to avoid sending invalid params (e.g. encoding_format=None)
+        # which vLLM rejects with: "unknown variant ``, expected float or base64"
+        filtered_params = {k: v for k, v in optional_params.items() if v is not None}
         return {
             "model": model,
             "input": input,
-            **optional_params,
+            **filtered_params,
         }
 
     def transform_embedding_response(
diff --git a/tests/mcp_tests/test_mcp_server.py b/tests/mcp_tests/test_mcp_server.py
index d3ec7863504..c5ad25d3014 100644
--- a/tests/mcp_tests/test_mcp_server.py
+++ b/tests/mcp_tests/test_mcp_server.py
@@ -395,6 +395,7 @@ async def test_mcp_http_transport_tool_not_found():
 @pytest.mark.asyncio
 async def test_streamable_http_mcp_handler_mock():
     """Test the streamable HTTP MCP handler functionality"""
+    from litellm.proxy._types import UserAPIKeyAuth
 
     # Mock the session manager and its methods
     mock_session_manager = AsyncMock()
@@ -413,12 +414,29 @@ async def test_streamable_http_mcp_handler_mock():
     mock_receive = AsyncMock()
     mock_send = AsyncMock()
 
+    mock_auth_result = (
+        UserAPIKeyAuth(),
+        None,
+        None,
+        {},
+        {},
+        [],
+    )
+
     with patch(
         "litellm.proxy._experimental.mcp_server.server._SESSION_MANAGERS_INITIALIZED",
         True,
     ), patch(
         "litellm.proxy._experimental.mcp_server.server.session_manager",
         mock_session_manager,
+    ), patch(
+        "litellm.proxy._experimental.mcp_server.server.extract_mcp_auth_context",
+        new=AsyncMock(return_value=mock_auth_result),
+    ), patch(
+        "litellm.proxy._experimental.mcp_server.server.set_auth_context",
+    ), patch(
+        "litellm.proxy._experimental.mcp_server.server._handle_stale_mcp_session",
+        new=AsyncMock(return_value=False),
     ):
         from litellm.proxy._experimental.mcp_server.server import (
             handle_streamable_http_mcp,
diff --git a/tests/test_litellm/llms/openrouter/responses/test_openrouter_responses_transformation.py b/tests/test_litellm/llms/openrouter/responses/test_openrouter_responses_transformation.py
index 544ec1ec719..0d12fdfba45 100644
--- a/tests/test_litellm/llms/openrouter/responses/test_openrouter_responses_transformation.py
+++ b/tests/test_litellm/llms/openrouter/responses/test_openrouter_responses_transformation.py
@@ -9,6 +9,8 @@ reasoning.encrypted_content for multi-turn stateless workflows.
 Related issue: https://github.com/BerriAI/litellm/issues/22189
 """
 
+from unittest.mock import patch
+
 import litellm
 from litellm.llms.openrouter.responses.transformation import (
     OpenRouterResponsesAPIConfig,
@@ -65,15 +67,21 @@ class TestOpenRouterResponsesAPIConfig:
         config = OpenRouterResponsesAPIConfig()
         from litellm.types.router import GenericLiteLLMParams
 
-        try:
-            config.validate_environment(
-                headers={},
-                model="openai/o4-mini",
-                litellm_params=GenericLiteLLMParams(),
-            )
-            assert False, "Should have raised ValueError"
-        except ValueError as e:
-            assert "OpenRouter API key is required" in str(e)
+        # Mock get_secret_str and litellm.api_key to ensure no API key is found,
+        # even in CI environments where OPENROUTER_API_KEY may be set.
+        with patch(
+            "litellm.llms.openrouter.responses.transformation.get_secret_str",
+            return_value=None,
+        ), patch.object(litellm, "api_key", None):
+            try:
+                config.validate_environment(
+                    headers={},
+                    model="openai/o4-mini",
+                    litellm_params=GenericLiteLLMParams(),
+                )
+                assert False, "Should have raised ValueError"
+            except ValueError as e:
+                assert "OpenRouter API key is required" in str(e)
 
 
 class TestOpenRouterResponsesAPIRegistration: