fix: avoid mutating raw schemas for responses tools

livekit-agents/livekit/agents/llm/_provider_format/openai.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import base64
+import copy
 from typing import Any, Literal
 
 from livekit.agents import llm
@@ -224,7 +225,7 @@ def to_responses_fnc_ctx(tool_ctx: llm.ToolContext, *, strict: bool = True) -> l
     schemas: list[dict[str, Any]] = []
     for tool in tool_ctx.flatten():
         if isinstance(tool, llm.RawFunctionTool):
-            schema = tool.info.raw_schema
+            schema = copy.deepcopy(tool.info.raw_schema)
             schema["type"] = "function"
             schemas.append(schema)
         elif isinstance(tool, llm.FunctionTool):

tests/test_tools.py

@@ -424,6 +424,26 @@ def test_strict_schema_no_parameters_has_no_required(self):
         assert "required" not in params
 
 
+class TestProviderSchemaFormatting:
+    def test_openai_responses_raw_schema_does_not_mutate_tool(self):
+        tool_ctx = ToolContext([raw_tool_1])
+        original_schema = dict(raw_tool_1.info.raw_schema)
+
+        schema = tool_ctx.parse_function_tools("openai.responses")[0]
+
+        assert schema["type"] == "function"
+        assert raw_tool_1.info.raw_schema == original_schema
+        assert "type" not in raw_tool_1.info.raw_schema
+
+    def test_openai_responses_raw_schema_isolated_from_caller_mutation(self):
+        tool_ctx = ToolContext([raw_tool_1])
+        schema = tool_ctx.parse_function_tools("openai.responses")[0]
+
+        schema["parameters"]["properties"]["extra"] = {"type": "string"}
+
+        assert "extra" not in raw_tool_1.info.raw_schema["parameters"]["properties"]
+
+
 class _NullableEnumModel(BaseModel):
     status: Literal["active", "inactive"] | None = Field(None)