open-swe/agent/middleware/sanitize_thinking_blocks.py

68 lines
2.1 KiB
Python
Raw Normal View History

"""Middleware that removes malformed Anthropic thinking blocks before model calls."""
from __future__ import annotations
from collections.abc import Awaitable, Callable
from typing import Any
from langchain.agents.middleware import AgentMiddleware
from langchain.agents.middleware.types import ModelCallResult, ModelRequest, ModelResponse
from langchain_anthropic import ChatAnthropic
from langchain_core.messages import AIMessage
def _is_chat_anthropic(model: object) -> bool:
seen: set[int] = set()
current = model
for _ in range(10):
if isinstance(current, ChatAnthropic):
return True
current_id = id(current)
if current_id in seen:
return False
seen.add(current_id)
bound = getattr(current, "bound", None)
if bound is None or bound is current:
return False
current = bound
return False
def _sanitize_messages(messages: list[Any]) -> None:
for message in messages:
if not isinstance(message, AIMessage) or not isinstance(message.content, list):
continue
content = [
block
for block in message.content
if not (
isinstance(block, dict)
and block.get("type") == "thinking"
and not block.get("thinking")
)
]
if len(content) != len(message.content):
message.content = content
class SanitizeThinkingBlocksMiddleware(AgentMiddleware):
"""Drop empty Anthropic thinking blocks before provider validation."""
def wrap_model_call(
self,
request: ModelRequest,
handler: Callable[[ModelRequest], ModelResponse],
) -> ModelCallResult:
if _is_chat_anthropic(request.model):
_sanitize_messages(request.messages)
return handler(request)
async def awrap_model_call(
self,
request: ModelRequest,
handler: Callable[[ModelRequest], Awaitable[ModelResponse]],
) -> Any:
if _is_chat_anthropic(request.model):
_sanitize_messages(request.messages)
return await handler(request)