structure saas with tools

.venv/lib/python3.10/site-packages/google/adk/tools/langchain_tool.py

@@ -0,0 +1,86 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import Any
+from typing import Callable
+
+from google.genai import types
+from pydantic import model_validator
+from typing_extensions import override
+
+from . import _automatic_function_calling_util
+from .function_tool import FunctionTool
+
+
+class LangchainTool(FunctionTool):
+  """Use this class to wrap a langchain tool.
+
+  If the original tool name and description are not suitable, you can override
+  them in the constructor.
+  """
+
+  tool: Any
+  """The wrapped langchain tool."""
+
+  def __init__(self, tool: Any):
+    super().__init__(tool._run)
+    self.tool = tool
+    if tool.name:
+      self.name = tool.name
+    if tool.description:
+      self.description = tool.description
+
+  @model_validator(mode='before')
+  @classmethod
+  def populate_name(cls, data: Any) -> Any:
+    # Override this to not use function's signature name as it's
+    # mostly "run" or "invoke" for thir-party tools.
+    return data
+
+  @override
+  def _get_declaration(self) -> types.FunctionDeclaration:
+    """Build the function declaration for the tool."""
+    from langchain.agents import Tool
+    from langchain_core.tools import BaseTool
+
+    # There are two types of tools:
+    # 1. BaseTool: the tool is defined in langchain.tools.
+    # 2. Other tools: the tool doesn't inherit any class but follow some
+    #    conventions, like having a "run" method.
+    if isinstance(self.tool, BaseTool):
+      tool_wrapper = Tool(
+          name=self.name,
+          func=self.func,
+          description=self.description,
+      )
+      if self.tool.args_schema:
+        tool_wrapper.args_schema = self.tool.args_schema
+      function_declaration = _automatic_function_calling_util.build_function_declaration_for_langchain(
+          False,
+          self.name,
+          self.description,
+          tool_wrapper.func,
+          tool_wrapper.args,
+      )
+      return function_declaration
+    else:
+      # Need to provide a way to override the function names and descriptions
+      # as the original function names are mostly ".run" and the descriptions
+      # may not meet users' needs.
+      function_declaration = (
+          _automatic_function_calling_util.build_function_declaration(
+              func=self.tool.run,
+          )
+      )
+      return function_declaration