reflex-dev/reflex · error · ValueError

OTP field `length` must be a positive integer.

Error message

OTP field `length` must be a positive integer.

What it means

The OTP field wrapper validates that `length` is a positive integer before generating that many OTPFieldInput children. Zero or negative lengths would render an empty/invalid OTP group, so Reflex fails fast with ValueError.

Source

Thrown at packages/reflex-components-internal/src/reflex_components_internal/components/base/otp_field.py:190

                auto-generated.
            TypeError: If `length` is not an integer when children are
                auto-generated (a Var can only be used with explicit children).
        """
        if children:
            if "length" not in props:
                msg = "OTP field `length` is required when passing children explicitly."
                raise ValueError(msg)
        else:
            length = props.setdefault("length", 6)
            if not isinstance(length, int) or isinstance(length, bool):
                msg = (
                    "OTP field high-level wrapper requires a static integer `length`."
                    " Pass children explicitly for dynamic lengths."
                )
                raise TypeError(msg)
            if length <= 0:
                msg = "OTP field `length` must be a positive integer."
                raise ValueError(msg)
            children = tuple(OTPFieldInput.create() for _ in range(length))

        return OTPFieldRoot.create(*children, **props)


class OTPField(ComponentNamespace):
    """Namespace for OTP field components."""

    root = staticmethod(OTPFieldRoot.create)
    input = staticmethod(OTPFieldInput.create)
    separator = staticmethod(OTPFieldSeparator.create)
    class_names = ClassNames
    __call__ = staticmethod(HighLevelOTPField.create)


otp_field = OTPField()

View on GitHub (pinned to 45b8ed5ab7)

Solutions

1. Pass a positive integer such as rx.otp_field(length=6)
2. Conditionally render the whole component instead of using length=0: rx.cond(State.show_otp, rx.otp_field(length=6))

Example fix

# before
rx.otp_field(length=0)
# after
rx.cond(State.show_otp, rx.otp_field(length=6))

if length <= 0:
    raise ValueError('OTP length must be >= 1')
rx.otp_field(length=length)

When it happens

Trigger: rx.otp_field(length=0), rx.otp_field(length=-1), or computing length from a constant that evaluates to <= 0.

Common situations: Using length=0 as a 'hide the field' trick, or deriving length from user config that can be zero.

Related errors

• Var-returning `@rx.memo` `{func_name}` cannot depend on embe
• Invalid prop(s) {invalid_fields_str} for {component_name!r}.
• default_color_mode must be one of {allowed_color_modes}, but
• Invalid event chain: {value!s} of type {value._var_type}
• Invalid event: {v}

AI-assisted analysis of reflex-dev/reflex@45b8ed5ab7 (2026-08-28). Data as JSON: /api/errors/083546a2fb1b292e. Report an issue: GitHub.