Validate Call

Decorator for validating function calls.

validate_call

def validate_call(
    *,
    config: ConfigDict | None = None,
    validate_return: bool = False,
) -> Callable[[AnyCallableT], AnyCallableT]
def validate_call(func: AnyCallableT, /) -> AnyCallableT

Usage Documentation

Validation Decorator

Returns a decorated wrapper around the function that validates the arguments and, optionally, the return value.

Usage may be either as a plain decorator @validate_call or with arguments @validate_call(...).

When a decorated call fails, the ValidationError names the rejected argument, but the traceback won’t show the value the caller passed. Logfire records failing calls along with their arguments — see Troubleshooting validation errors.

Returns

AnyCallableT | Callable[[AnyCallableT], AnyCallableT] — The decorated function.

Parameters

func : AnyCallableT | None Default: None

The function to be decorated.

config : ConfigDict | None Default: None

The configuration dictionary.

validate_return : bool Default: False

Whether to validate the return value.