Files
langchain/libs/partners/anthropic/langchain_anthropic/middleware/bash.py
Sydney Runkle 6a1dca113e chore: move ToolNode improvements back to langgraph (#33634)
Moving all `ToolNode` related improvements back to LangGraph and
importing them in LC!
pairing w/ https://github.com/langchain-ai/langgraph/pull/6321

this fixes a couple of things:
1. `InjectedState`, store etc will continue to work as expected no
matter where the import is from
2. `ToolRuntime` is now usable w/in langgraph, woohoo!
2025-10-29 11:44:23 -07:00

96 lines
3.2 KiB
Python

"""Anthropic-specific middleware for the Claude bash tool."""
from __future__ import annotations
from collections.abc import Awaitable, Callable
from typing import Any, Literal
from langchain.agents.middleware.shell_tool import ShellToolMiddleware
from langchain.agents.middleware.types import (
ModelRequest,
ModelResponse,
ToolCallRequest,
)
from langchain_core.messages import ToolMessage
from langgraph.types import Command
_CLAUDE_BASH_DESCRIPTOR = {"type": "bash_20250124", "name": "bash"}
class ClaudeBashToolMiddleware(ShellToolMiddleware):
"""Middleware that exposes Anthropic's native bash tool to models."""
def __init__(self, *args: Any, **kwargs: Any) -> None:
"""Initialize middleware without registering a client-side tool."""
kwargs["shell_command"] = ("/bin/bash",)
super().__init__(*args, **kwargs)
# Remove the base tool so Claude's native descriptor is the sole entry.
self._tool = None # type: ignore[assignment]
self.tools = []
def wrap_model_call(
self,
request: ModelRequest,
handler: Callable[[ModelRequest], ModelResponse],
) -> ModelResponse:
"""Ensure the Claude bash descriptor is available to the model."""
tools = request.tools
if all(tool is not _CLAUDE_BASH_DESCRIPTOR for tool in tools):
tools = [*tools, _CLAUDE_BASH_DESCRIPTOR]
request = request.override(tools=tools)
return handler(request)
def wrap_tool_call(
self,
request: ToolCallRequest,
handler: Callable[[ToolCallRequest], Command | ToolMessage],
) -> Command | ToolMessage:
"""Intercept Claude bash tool calls and execute them locally."""
tool_call = request.tool_call
if tool_call.get("name") != "bash":
return handler(request)
resources = self._ensure_resources(request.state)
return self._run_shell_tool(
resources,
tool_call["args"],
tool_call_id=tool_call.get("id"),
)
async def awrap_tool_call(
self,
request: ToolCallRequest,
handler: Callable[[ToolCallRequest], Awaitable[Command | ToolMessage]],
) -> Command | ToolMessage:
"""Async interception mirroring the synchronous implementation."""
tool_call = request.tool_call
if tool_call.get("name") != "bash":
return await handler(request)
resources = self._ensure_resources(request.state)
return self._run_shell_tool(
resources,
tool_call["args"],
tool_call_id=tool_call.get("id"),
)
def _format_tool_message(
self,
content: str,
tool_call_id: str | None,
*,
status: Literal["success", "error"],
artifact: dict[str, Any] | None = None,
) -> ToolMessage | str:
"""Format tool responses using Claude's bash descriptor."""
if tool_call_id is None:
return content
return ToolMessage(
content=content,
tool_call_id=tool_call_id,
name=_CLAUDE_BASH_DESCRIPTOR["name"],
status=status,
artifact=artifact or {},
)
__all__ = ["ClaudeBashToolMiddleware"]