from contextvars import ContextVar

buffer: ContextVar[str] = ContextVar("buffer", default="")
tool_buffer: ContextVar[str] = ContextVar("tool_buffer", default="")
tool_id: ContextVar[str | None] = ContextVar("tool_id", default=None)
tool_name: ContextVar[str | None] = ContextVar("tool_name", default=None)