Sandboxed coding assistant

import asyncio
from pathlib import Path
from loomflow import Agent, Mode, StandardPermissions, tool
from loomflow.security import FileAuditLog, FilesystemSandbox
from loomflow.tools import InProcessToolHost
 
WORKSPACE = Path("./workspace").resolve()
 
@tool
def read_file(path: str) -> str:
    """Read a file from the workspace."""
    return Path(path).read_text()
 
@tool(destructive=True)
def write_file(path: str, content: str) -> str:
    """Write content to a file (destructive — requires approval)."""
    Path(path).write_text(content)
    return f"wrote {len(content)} bytes to {path}"
 
async def main():
    inner = InProcessToolHost([read_file, write_file])
    sandbox = FilesystemSandbox(inner, roots=[WORKSPACE])
 
    agent = Agent(
        "You are a coding assistant. Only touch files inside the workspace.",
        model="claude-opus-4-7",
        tools=sandbox,
        permissions=StandardPermissions(mode=Mode.ACCEPT_EDITS),
        audit_log=FileAuditLog("./audit.jsonl", secret="prod-secret"),
    )
 
    @agent.before_tool
    async def confirm_destructive(call):
        if call.tool == "write_file":
            answer = input(f"Allow write to {call.args.get('path')}? [y/N] ")
            if answer.strip().lower() != "y":
                from loomflow.core.types import PermissionDecision
                return PermissionDecision.deny_("user declined")
        return None
 
    await agent.run("Refactor utils.py to use type hints.")
 
asyncio.run(main())