Merge pull request #42352 from BerriAI/litellm_mcp_tools_camelcase_keys

fix(mcp): return camelCase tool keys from /v1/mcp/tools after the SDK 2 upgrade

litellm/proxy/management_endpoints/mcp_management_endpoints.py

@@ -983,7 +983,7 @@ if MCP_AVAILABLE:
             mcp_server_auth_headers=None,
         )
         tools: Final = listing.tools
-        dumped_tools: Final = [dict(tool) for tool in tools]
+        dumped_tools: Final = [tool.model_dump(by_alias=True) for tool in tools]
 
         return {"tools": dumped_tools}
 

litellm/responses/mcp/mcp_streaming_iterator.py

@@ -91,16 +91,6 @@ async def create_mcp_list_tools_events(
         # Use the pre-processed MCP tools that were already fetched, filtered, and deduplicated by the parent
         filtered_mcp_tools: Final = pre_processed_mcp_tools
 
-        # Convert tools to dict format for the event
-        _mcp_tools_dict: Final = [
-            tool.model_dump()
-            if hasattr(tool, "model_dump") and callable(getattr(tool, "model_dump", None))
-            else tool.__dict__
-            if hasattr(tool, "__dict__")
-            else {"name": getattr(tool, "name", str(tool))}
-            for tool in filtered_mcp_tools
-        ]
-
         # Emit list tools completed event
         completed_event: Final = MCPListToolsCompletedEvent(
             type=ResponsesAPIStreamEvents.MCP_LIST_TOOLS_COMPLETED,

tests/test_litellm/proxy/management_endpoints/test_mcp_management_endpoints.py

@@ -7878,3 +7878,25 @@ class TestDeleteMCPGatewaySessions:
         assert result.terminated_sessions == 2
         assert {s.user_id for s in result.sessions} == {"bob"}
         assert "sk-live-bob" not in result.model_dump_json()
+
+
+class TestGetMcpToolsWireShape:
+    @pytest.mark.asyncio
+    async def test_get_mcp_tools_returns_each_tool_in_mcp_wire_spelling(self):
+        from mcp.types import ListToolsResult, Tool
+
+        add_schema = {"type": "object", "properties": {"a": {"type": "integer"}}, "required": ["a"]}
+        listed = ListToolsResult(
+            tools=[Tool(name="add", description="Add", inputSchema=add_schema, outputSchema={"type": "integer"})]
+        )
+        with patch(
+            "litellm.proxy._experimental.mcp_server.server._list_mcp_tools",
+            AsyncMock(return_value=listed),
+        ):
+            result = await mgmt_endpoints.get_mcp_tools(user_api_key_dict=generate_mock_user_api_key_auth())
+
+        (tool,) = result["tools"]
+        assert tool["inputSchema"] == add_schema
+        assert tool["outputSchema"] == {"type": "integer"}
+        assert "_meta" in tool
+        assert not {"input_schema", "output_schema", "meta"} & tool.keys()