reflex-dev/reflex · error · ValueError

IconButton requires a child icon. Pass a string as the…

Error message

IconButton requires a child icon. Pass a string as the first child or a rx.icon.

What it means

rx.icon_button (Radix theme) requires an icon: either a string icon name as the first child or an rx.icon component. Without it there is nothing to render inside the button, so ValueError is raised at creation time.

Solutions

1. Pass a name: rx.icon_button('trash', on_click=State.delete)
2. Or a full icon component: rx.icon_button(rx.icon('trash', size=18))

Example fix

# before
rx.icon_button(on_click=State.delete)
# after
rx.icon_button('trash', on_click=State.delete)

icon = cfg.get('icon') or 'circle'
rx.icon_button(icon, on_click=handler)

When it happens

Trigger: rx.icon_button(on_click=...) with no children, or passing only keyword props.

Common situations: Refactoring that drops the icon argument; building buttons from a config dict where the icon key is missing.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

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AI-assisted analysis of reflex-dev/reflex@45b8ed5ab7 (2026-08-28). Data as JSON: /api/errors/6f55c5ecefd78a16. Report an issue: GitHub.

Appendix: source

Thrown at packages/reflex-components-radix/src/reflex_components_radix/themes/components/icon_button.py:76

            *children: The children of the component.
            **props: The properties of the component.

        Returns:
            The IconButton component.

        Raises:
            ValueError: If no children are passed.
        """
        if children:
            if isinstance(children[0], str):
                children = [
                    Icon.create(
                        children[0],
                    )
                ]
        else:
            msg = "IconButton requires a child icon. Pass a string as the first child or a rx.icon."
            raise ValueError(msg)
        if "size" in props:
            if isinstance(props["size"], str):
                children[0].size = RADIX_TO_LUCIDE_SIZE[props["size"]]  # pyright: ignore[reportAttributeAccessIssue]
            else:
                size_map_var = Match.create(
                    props["size"],
                    *list(RADIX_TO_LUCIDE_SIZE.items()),
                    12,
                )
                if not isinstance(size_map_var, Var):
                    msg = f"Match did not return a Var: {size_map_var}"
                    raise ValueError(msg)
                children[0].size = size_map_var  # pyright: ignore[reportAttributeAccessIssue]
        return super().create(*children, **props)

    def add_style(self):
        """Add style to the component.

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