feat(genai): add support to built-in url_context tool (#1371)

Author: wilyJ80

libs/genai/langchain_google_genai/_function_utils.py

@@ -55,13 +55,15 @@
 
 _GoogleSearchLike = gapic.Tool.GoogleSearch | dict[str, Any]
 _CodeExecutionLike = gapic.CodeExecution | dict[str, Any]
+_UrlContextLike = gapic.UrlContext | dict[str, Any]
 
 
 class _ToolDict(TypedDict):
     function_declarations: Sequence[_FunctionDeclarationLike]
     google_search_retrieval: _GoogleSearchRetrievalLike | None
     google_search: NotRequired[_GoogleSearchLike]
     code_execution: NotRequired[_CodeExecutionLike]
+    url_context: NotRequired[_UrlContextLike]
 
 
 # Info: This means one tool=Sequence of FunctionDeclaration
@@ -153,6 +155,7 @@ def convert_to_genai_function_declarations(
                     "google_search_retrieval",
                     "google_search",
                     "code_execution",
+                    "url_context",
                 ]
             ):
                 fd = _format_to_gapic_function_declaration(tool)  # type: ignore[arg-type]
@@ -186,6 +189,8 @@ def convert_to_genai_function_declarations(
                 )
             if "code_execution" in tool:
                 gapic_tool.code_execution = gapic.CodeExecution(tool["code_execution"])
+            if "url_context" in tool:
+                gapic_tool.url_context = gapic.UrlContext(tool["url_context"])
         else:
             fd = _format_to_gapic_function_declaration(tool)
             gapic_tool.function_declarations.append(fd)

libs/genai/tests/integration_tests/test_builtin_tools.py

@@ -0,0 +1,21 @@
+from langchain_core.messages import AIMessage
+
+from langchain_google_genai import ChatGoogleGenerativeAI
+
+_MODEL = "gemini-2.5-flash"
+
+
+def test_url_context_tool() -> None:
+    model = ChatGoogleGenerativeAI(model=_MODEL)
+    model_with_search = model.bind_tools([{"url_context": {}}])
+
+    input = "What is this page's contents about? https://docs.langchain.com"
+    response = model_with_search.invoke(input)
+    assert isinstance(response, AIMessage)
+
+    assert (
+        response.response_metadata["grounding_metadata"]["grounding_chunks"][0]["web"][
+            "uri"
+        ]
+        is not None
+    )