feat(core): automatic set required to include all properties in strict mode (#32930)

Author: zhongyu09

libs/core/langchain_core/utils/function_calling.py

@@ -425,6 +425,10 @@ def convert_to_openai_function(
             oai_function["parameters"] = _recursive_set_additional_properties_false(
                 oai_function["parameters"]
             )
+            # All fields must be `required`
+            fields = oai_function["parameters"].get("properties", {})
+            if isinstance(fields, dict) and fields:
+                oai_function["parameters"]["required"] = list(fields.keys())
     return oai_function
 
 

libs/core/tests/unit_tests/utils/test_function_calling.py

@@ -1155,3 +1155,16 @@ def my_function(arg1: dict, arg2: dict | None) -> None:
 
     actual = convert_to_openai_function(my_function, strict=True)
     assert actual == expected
+
+
+def test_convert_to_openai_function_strict_required() -> None:
+    class MyModel(BaseModel):
+        """Dummy schema."""
+
+        arg1: int = Field(..., description="foo")
+        arg2: str | None = Field(None, description="bar")
+
+    expected = ["arg1", "arg2"]
+    func = convert_to_openai_function(MyModel, strict=True)
+    actual = func["parameters"]["required"]
+    assert actual == expected