axio-tui-guards 0.9.4

Guards plugin for Axio TUI

axio-tui-guards

Permission guard plugins for axio-tui.

Guards intercept tool calls before execution and can allow, modify, or deny them. Ships two guards: a path-access guard that asks the user before touching filesystem locations, and an LLM-based guard that reviews tool calls for safety.

Features

• PathGuard - intercepts tools that touch the filesystem; prompts the user once per directory and remembers the decision for the session
• LLMGuard - runs a secondary LLM call to review each tool invocation before allowing it
• PermissionGuard protocol - both guards implement axio.PermissionGuard and compose cleanly
• TUI-aware - prompts appear as native axio-tui dialogs, not blocking stdin reads

Installation

pip install axio-tui-guards

Or install as part of the TUI bundle:

pip install "axio-tui[guards]"

Guards

PathGuard

Intercepts tool calls that contain filesystem paths (file_path, filename, directory, path, cwd). On the first access to a new directory it asks the user to allow, allow all (subtree), or deny.

from axio_tui_guards.guards import PathGuard
from axio.tool import Tool

guard = PathGuard()   # uses TUI prompt_fn by default

tool = Tool(
    name="write_file",
    description="Write a file",
    handler=write_file,
    guards=(guard,),
)

Decision caching:

• Allow - grants access to the parent directory for the current session
• Allow all - grants access to the directory and all subdirectories
• Deny - blocks this path; raises GuardError immediately on retry

LLMGuard

Uses a secondary LLM call to review the tool handler arguments before execution. If the reviewer deems the call unsafe it raises GuardError with the reason.

from axio_tui_guards.guards import LLMGuard
from axio.agent import Agent
from axio.context import MemoryContextStore
from axio.testing import StubTransport, make_text_response

reviewer = Agent(system="", tools=[], transport=StubTransport([make_text_response("allow")]))
guard = LLMGuard(agent=reviewer, context=MemoryContextStore())

Composing guards

Guards are applied in order - attach both for layered protection:

from axio_tui_guards.guards import PathGuard, LLMGuard
from axio.agent import Agent
from axio.context import MemoryContextStore
from axio.testing import StubTransport, make_text_response
from axio.tool import Tool

reviewer = Agent(system="", tools=[], transport=StubTransport([make_text_response("allow")]))
tool = Tool(
    name="shell",
    description="Run shell commands",
    handler=shell,
    guards=(PathGuard(), LLMGuard(agent=reviewer, context=MemoryContextStore())),
)

Custom guards

Implement the PermissionGuard protocol to write your own:

from typing import Any
from axio.permission import PermissionGuard
from axio.exceptions import GuardError

class MyGuard(PermissionGuard):
    async def check(self, tool: Any, **kwargs: Any) -> dict[str, Any]:
        if "rm -rf" in str(kwargs.get("command", "")):
            raise GuardError("Refusing to run rm -rf")
        return kwargs

Plugin registration

[project.entry-points."axio.guards"]
path = "axio_tui_guards.guards:PathGuard"
llm  = "axio_tui_guards.guards:LLMGuard"

Part of the axio ecosystem

axio · axio-tui

License

MIT