fix(genai): emit items schema for List[Any] tool parameters#1805
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obchain (obchain) wants to merge 1 commit into
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fix(genai): emit items schema for List[Any] tool parameters#1805obchain (obchain) wants to merge 1 commit into
obchain (obchain) wants to merge 1 commit into
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Pydantic v2 emits a valid `"items": {}` for `List[Any]` array fields.
`_get_properties_from_schema` guarded with `v.get("items")`, which is
falsy for `{}`, so the `items` field was dropped from the resulting
FunctionDeclaration. Gemini then rejects the request with
`400 INVALID_ARGUMENT: ...properties[...].items: missing field`.
Switch to `"items" in v` (matching the equivalent check in
`langchain-google-vertexai`) so an empty items schema is still
forwarded to `_get_items_from_schema_any`, which defaults the inner
type to STRING.
Fixes langchain-ai#1768
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Description
ChatGoogleGenerativeAIinvocations with tools that takeList[Any]parameters fail at runtime with:Root cause: Pydantic v2 emits a valid
"items": {}for an untyped array. In_get_properties_from_schema(libs/genai/langchain_google_genai/_function_utils.py) the guard wasv.get("items"), which is falsy for{}, so theitemsfield was dropped from the FunctionDeclaration. Gemini rejects array fields withoutitems.langchain-google-vertexaialready uses a key-existence check ("items" in property); this PR alignslangchain-google-genaiwith that. An emptyitemsschema is now forwarded to_get_items_from_schema_any, which defaults the inner type toSTRING— the minimal payload Gemini accepts for an untyped array.Relevant issues
Fixes #1768
Type
🐛 Bug Fix
Changes
libs/genai/langchain_google_genai/_function_utils.py: switchv.get("items")to"items" in vat the array-property check.libs/genai/tests/unit_tests/test_function_utils.py: addtest_tool_with_list_any_param_emits_itemsregression covering theList[Any]→itemsshape.Testing
uv run --group test pytest tests/unit_tests/test_function_utils.py— 28 passed.main(stashing the source change) and passes with the fix.make lint(ruff) andmypyclean for the touched files.