ToolGuard

from toolguard import Guard, guarded, RequiredKeysRule, TypesRule, BoundsRule

# Define a simple rule set for a fake "charge" tool.
my_guard = Guard(
    {
        "charge": [
            RequiredKeysRule(["amount", "currency"]),
            TypesRule({"amount": "int", "currency": "str"}),
            BoundsRule("amount", min=1),  # amount must be a positive integer
        ]
    }
)

# Decorate the implementation so every call is validated first.
@guarded(my_guard, "charge")
def charge(amount: int, currency: str):
    """Pretend to charge a credit card."""
    print(f"[charge] Successfully charged {amount} {currency}.")

def main() -> None:
    print("=== Valid call ===")
    charge(2500, "usd")  # Should succeed.