core[patch]: support tool calls with non-pickleable args in tools (#2…

…4741)

Deepcopy raises with non-pickleable args.

libs/core/langchain_core/tools.py

@@ -20,7 +20,6 @@
 from __future__ import annotations
 
 import asyncio
-import copy
 import functools
 import inspect
 import json
@@ -1491,9 +1490,8 @@ def _prep_run_args(
 ) -> Tuple[Union[str, Dict], Dict]:
     config = ensure_config(config)
     if _is_tool_call(input):
-        input_copy = copy.deepcopy(input)
-        tool_call_id: Optional[str] = cast(ToolCall, input_copy)["id"]
-        tool_input: Union[str, dict] = cast(ToolCall, input_copy)["args"]
+        tool_call_id: Optional[str] = cast(ToolCall, input)["id"]
+        tool_input: Union[str, dict] = cast(ToolCall, input)["args"].copy()
     else:
         tool_call_id = None
         tool_input = cast(Union[str, dict], input)

libs/core/tests/unit_tests/test_tools.py

@@ -4,6 +4,7 @@
 import json
 import sys
 import textwrap
+import threading
 from datetime import datetime
 from enum import Enum
 from functools import partial
@@ -977,7 +978,7 @@ async def _arun(self, bar: Any, bar_config: RunnableConfig, **kwargs: Any) -> An
 def test_tool_pass_config(tool: BaseTool) -> None:
     assert tool.invoke({"bar": "baz"}, {"configurable": {"foo": "not-bar"}}) == "baz"
 
-    # Test tool calls
+    # Test we don't mutate tool calls
     tool_call = {
         "name": tool.name,
         "args": {"bar": "baz"},
@@ -988,6 +989,25 @@ def test_tool_pass_config(tool: BaseTool) -> None:
     assert tool_call["args"] == {"bar": "baz"}
 
 
+class FooBaseNonPickleable(FooBase):
+    def _run(self, bar: Any, bar_config: RunnableConfig, **kwargs: Any) -> Any:
+        return True
+
+
+def test_tool_pass_config_non_pickleable() -> None:
+    tool = FooBaseNonPickleable()
+
+    args = {"bar": threading.Lock()}
+    tool_call = {
+        "name": tool.name,
+        "args": args,
+        "id": "abc123",
+        "type": "tool_call",
+    }
+    _ = tool.invoke(tool_call, {"configurable": {"foo": "not-bar"}})
+    assert tool_call["args"] == args
+
+
 @pytest.mark.parametrize(
     "tool", [foo, afoo, simple_foo, asimple_foo, FooBase(), AFooBase()]
 )