From feb351737c55a45344b9fed0d22a98996ee18362 Mon Sep 17 00:00:00 2001
From: Bagatur <22008038+baskaryan@users.noreply.github.com>
Date: Wed, 11 Sep 2024 16:06:03 -0700
Subject: [PATCH] core[patch]: fix empty OpenAI tools when strict=True (#26287)

Fix #26232

---------

Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>
---
 .../langchain_core/utils/function_calling.py  |  8 ++++++--
 .../unit_tests/utils/test_function_calling.py | 19 +++++++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/libs/core/langchain_core/utils/function_calling.py b/libs/core/langchain_core/utils/function_calling.py
index 67ac7ebd7f966..9e239eba37264 100644
--- a/libs/core/langchain_core/utils/function_calling.py
+++ b/libs/core/langchain_core/utils/function_calling.py
@@ -605,9 +605,13 @@ def _recursive_set_additional_properties_false(
     schema: Dict[str, Any],
 ) -> Dict[str, Any]:
     if isinstance(schema, dict):
-        # Check if 'required' is a key at the current level
-        if "required" in schema:
+        # Check if 'required' is a key at the current level or if the schema is empty,
+        # in which case additionalProperties still needs to be specified.
+        if "required" in schema or (
+            "properties" in schema and not schema["properties"]
+        ):
             schema["additionalProperties"] = False
+
         # Recursively check 'properties' and 'items' if they exist
         if "properties" in schema:
             for value in schema["properties"].values():
diff --git a/libs/core/tests/unit_tests/utils/test_function_calling.py b/libs/core/tests/unit_tests/utils/test_function_calling.py
index 9570c52d4c273..fee5f4778b103 100644
--- a/libs/core/tests/unit_tests/utils/test_function_calling.py
+++ b/libs/core/tests/unit_tests/utils/test_function_calling.py
@@ -793,3 +793,22 @@ def magic_function(input: int | float) -> str:
     assert result["parameters"]["properties"]["input"] == {
         "anyOf": [{"type": "integer"}, {"type": "number"}]
     }
+
+
+def test_convert_to_openai_function_no_args() -> None:
+    @tool
+    def empty_tool() -> str:
+        """No args"""
+        return "foo"
+
+    actual = convert_to_openai_function(empty_tool, strict=True)
+    assert actual == {
+        "name": "empty_tool",
+        "description": "No args",
+        "parameters": {
+            "properties": {},
+            "additionalProperties": False,
+            "type": "object",
+        },
+        "strict": True,
+    }