chore(langchain_v1): move tool node to tools namespace (#33132)

* Move ToolNode to tools namespace
* Expose injected variable as well in tools namespace
* Update doc-strings throughout

Author: eyurtsev

libs/langchain_v1/langchain/agents/__init__.py

@@ -1,7 +1,7 @@
 """langgraph.prebuilt exposes a higher-level API for creating and executing agents and tools."""
 
 from langchain.agents.react_agent import AgentState, create_agent
-from langchain.agents.tool_node import ToolNode
+from langchain.tools import ToolNode
 
 __all__ = [
     "AgentState",

libs/langchain_v1/langchain/agents/middleware_agent.py

@@ -33,8 +33,8 @@
     StructuredOutputValidationError,
     ToolStrategy,
 )
-from langchain.agents.tool_node import ToolNode
 from langchain.chat_models import init_chat_model
+from langchain.tools import ToolNode
 
 STRUCTURED_OUTPUT_ERROR_TEMPLATE = "Error: {error}\n Please fix your mistakes."
 

libs/langchain_v1/langchain/agents/react_agent.py

@@ -54,8 +54,8 @@
     StructuredOutputValidationError,
     ToolStrategy,
 )
-from langchain.agents.tool_node import ToolNode
 from langchain.chat_models import init_chat_model
+from langchain.tools import ToolNode
 
 if TYPE_CHECKING:
     from langchain_core.tools import BaseTool

libs/langchain_v1/langchain/tools/__init__.py

@@ -8,10 +8,19 @@
     tool,
 )
 
+from langchain.tools.tool_node import (
+    InjectedState,
+    InjectedStore,
+    ToolNode,
+)
+
 __all__ = [
     "BaseTool",
+    "InjectedState",
+    "InjectedStore",
     "InjectedToolArg",
     "InjectedToolCallId",
     "ToolException",
+    "ToolNode",
     "tool",
 ]

libs/langchain_v1/langchain/agents/tool_node.py renamed to libs/langchain_v1/langchain/tools/tool_node.py

@@ -21,7 +21,7 @@
 Typical Usage:
     ```python
     from langchain_core.tools import tool
-    from langchain.agents import ToolNode
+    from langchain.tools import ToolNode
 
 
     @tool
@@ -344,7 +344,7 @@ class ToolNode(RunnableCallable):
         Basic usage:
 
         ```python
-        from langchain.agents import ToolNode
+        from langchain.tools import ToolNode
         from langchain_core.tools import tool
 
         @tool
@@ -359,7 +359,7 @@ def calculator(a: int, b: int) -> int:
 
         ```python
         from typing_extensions import Annotated
-        from langgraph.agents.tool_node import InjectedState
+        from langchain.tools import InjectedState
 
         @tool
         def context_tool(query: str, state: Annotated[dict, InjectedState]) -> str:
@@ -885,7 +885,8 @@ def tools_condition(
 
         ```python
         from langgraph.graph import StateGraph
-        from langgraph.agents.tool_node import ToolNode, tools_condition
+        from langchain.tools import ToolNode
+        from langchain.tools.tool_node import tools_condition
         from typing_extensions import TypedDict
 
 
@@ -950,9 +951,7 @@ class InjectedState(InjectedToolArg):
         from typing_extensions import Annotated, TypedDict
 
         from langchain_core.messages import BaseMessage, AIMessage
-        from langchain_core.tools import tool
-
-        from langgraph.agents.tool_node import InjectedState, ToolNode
+        from langchain.tools import InjectedState, ToolNode, tool
 
 
         class AgentState(TypedDict):
@@ -1026,9 +1025,8 @@ class InjectedStore(InjectedToolArg):
     Example:
         ```python
         from typing_extensions import Annotated
-        from langchain_core.tools import tool
         from langgraph.store.memory import InMemoryStore
-        from langgraph.agents.tool_node import InjectedStore, ToolNode
+        from langchain.tools import InjectedStore, ToolNode, tool
 
         @tool
         def save_preference(

libs/langchain_v1/pyproject.toml

@@ -171,6 +171,16 @@ ignore-var-parameters = true  # ignore missing documentation for *args and **kwa
     "N801", # class name should use CapWords convention
 ]
 
+"langchain/tools/tool_node.py" = [
+    "ANN401", # we use Any right now, need to narrow
+    "A002", # input is shadowing builtin
+    "A001", # input is shadowing builtin
+    "B904", # use from for exceptions
+    "PLR2004", # magic values are fine for this case
+    "C901", # too complex
+    "TRY004", # type error exception
+]
+
 [tool.coverage.run]
 omit = ["tests/*"]
 

libs/langchain_v1/tests/unit_tests/agents/test_middleware_agent.py

@@ -21,7 +21,7 @@
 from langchain_core.tools import tool, InjectedToolCallId
 
 from langchain.agents.middleware_agent import create_agent
-from langchain.agents.tool_node import InjectedState
+from langchain.tools import InjectedState
 from langchain.agents.middleware.human_in_the_loop import (
     HumanInTheLoopMiddleware,
     ActionRequest,

libs/langchain_v1/tests/unit_tests/agents/test_react_agent.py

@@ -36,9 +36,11 @@
     create_agent,
 )
 from langchain.agents.react_agent import _validate_chat_history
-from langchain.agents.tool_node import (
+from langchain.tools import (
     InjectedState,
     InjectedStore,
+)
+from langchain.tools.tool_node import (
     _get_state_args,
     _infer_handled_types,
 )

libs/langchain_v1/tests/unit_tests/agents/test_tool_node.py

@@ -35,13 +35,11 @@
 from langchain.agents import (
     ToolNode,
 )
-from langchain.agents.tool_node import (
-    TOOL_CALL_ERROR_TEMPLATE,
+from langchain.tools import (
     InjectedState,
     InjectedStore,
-    ToolInvocationError,
-    tools_condition,
 )
+from langchain.tools.tool_node import TOOL_CALL_ERROR_TEMPLATE, ToolInvocationError, tools_condition
 
 from .messages import _AnyIdHumanMessage, _AnyIdToolMessage
 from .model import FakeToolCallingModel

libs/langchain_v1/tests/unit_tests/tools/test_imports.py

@@ -2,9 +2,12 @@
 
 EXPECTED_ALL = {
     "BaseTool",
+    "InjectedState",
+    "InjectedStore",
     "InjectedToolArg",
     "InjectedToolCallId",
     "ToolException",
+    "ToolNode",
     "tool",
 }