using-base-ui-with-material-ui by siriwatknp

---
name: using-base-ui-with-material-ui
description: Always use this skill when integrating Base UI components `@base-ui-components/react` with Material UI `@mui/material`.
---

**Announce on start**: You must announce "Using Base UI with Material UI skill" when this skill is invoked.

Always have enough context from the [Base UI documentation](https://base-ui.com/llms.txt) to build the component requested by the user.

## Base UI as the foundation

Render Base UI components as a foundation for the UI and then pass `render` prop using **proper** Material UI components.

For example, a Navigation Menu, should use `Link` from Material UI as the render element for `NavigationMenu.Link`.:

```tsx
import { NavigationMenu } from "@base-ui-components/react/navigation-menu";
import Box from "@mui/material/Box";
import Link from "@mui/material/Link";
import Typography from "@mui/material/Typography";

function MenuLink({
  icon,
  title,
  description,
  ...props
}: NavigationMenu.Link.Props & {
  icon?: React.ReactNode;
  title: string;
  description: string;
}) {
  return (
    <NavigationMenu.Link
      href="#"
      {...props}
      render={
        <Link
          underline="none"
          sx={{
            display: "flex",
            gap: 1,
            p: 1.5,
            borderRadius: 0.5,
            cursor: "pointer",
            transition: "background-color 0.2s",
            "@media (hover: hover)": {
              "&:hover": {
                bgcolor: "action.hover",
              },
            },
          }}
        />
      }
    >
      <Box sx={{ color: "primary.main", display: "flex", mt: 0.25 }}>
        {icon}
      </Box>
      <Box>
        <Typography variant="subtitle2" sx={{ fontWeight: 600, mb: 0.25 }}>
          {title}
        </Typography>
        <Typography
          variant="body2"
          sx={{ color: "text.secondary", lineHeight: 1.4 }}
        >
          {description}
        </Typography>
      </Box>
    </NavigationMenu.Link>
  );
}
```

For full example, see [nav-menu-01.tsx](registry/blocks/nav-menu-01/nav-menu-01.tsx)

Another example, using `Button` from Material UI as the render element for Base UI `Trigger` component:

```tsx
import { Menu } from "@base-ui-components/react/menu";
import Button from "@mui/material/Button";

<Menu.Trigger render={<Button />}>File</Menu.Trigger>;
```

## Styling

To style Base UI components, use `<Box />` as a render element and pass `sx` prop to it.
Always keep in mind that the sx values should be minimum since Material UI components already have default styling.

```tsx
import { NavigationMenu } from "@base-ui-components/react/navigation-menu";
import Box from "@mui/material/Box";

<NavigationMenu.List
  render={
    <Box
      component="ul"
      sx={{
        display: "flex",
        justifyContent: "center",
        gap: 2,
        listStyle: "none",
        "& .MuiButton-root[data-popup-open]": {
          bgcolor: "action.selected",
        },
      }}
    />
  }
></NavigationMenu.List>;
```

## Primitive/Non-interactive Components

For non-interactive Base UI components like Meter, Progress, Slider (read-only), etc. that don't have direct semantic Material UI equivalents, **always use the `render` prop pattern with `Box`**.

**CRITICAL:** Never use `component={BaseUIComponent}` - this is incorrect and causes issues. Always use Base UI components as the foundation with the `render` prop.

### ✅ Correct Pattern

```tsx
import { Meter } from "@base-ui-components/react/meter";
import Box from "@mui/material/Box";

<Meter.Track
  render={
    <Box
      sx={{
        height: 8,
        width: "100%",
        bgcolor: "action.disabledBackground",
        borderRadius: 1,
        overflow: "hidden",
        position: "relative",
      }}
    />
  }
>
  <Meter.Indicator
    render={
      <Box
        sx={{
          height: "100%",
          bgcolor: "text.primary",
          transition: "width 0.3s ease",
        }}
      />
    }
  />
</Meter.Track>;
```

### ❌ Incorrect Pattern

```tsx
// ❌ NEVER do this - Base UI should be the foundation, not MUI Box
<Box component={Meter.Track} sx={{ ... }}>
  <Box component={Meter.Indicator} sx={{ ... }} />
</Box>

// ❌ NEVER do this - Using asChild prop (not a React pattern)
<Meter.Track asChild>
  <Box sx={{ ... }}>
    <Meter.Indicator asChild>
      <Box sx={{ ... }} />
    </Meter.Indicator>
  </Box>
</Meter.Track>
```

### Key Points

1. **Base UI First**: Always render Base UI components as the outer wrapper
2. **render Prop**: Use `render={<Box sx={{ ... }} />}` to apply Material UI styling
3. **Theme Tokens**: Use MUI theme tokens in sx prop (e.g., `bgcolor: "action.hover"`, `color: "text.primary"`)
4. **Minimal Styling**: Keep sx props minimal - only add what's necessary for the design

## Reduce duplication

If the same styles are used multiple times for the same Base UI components, create wrapper components to reduce duplication.

```tsx
import { NavigationMenu } from "@base-ui-components/react/navigation-menu";

function Content(props: BoxProps) {
  return (
    <Box
      sx={{
        padding: 1,
        width: "calc(100vw - 40px)",
        height: "100%",
        "@media (min-width: 500px)": {
          width: "max-content",
          minWidth: "400px",
        },
      }}
      {...props}
    />
  );
}

<NavigationMenu.List>
  <NavigationMenu.Item>
    <NavigationMenu.Content render={<Content />}></NavigationMenu.Content>
  </NavigationMenu.Item>
  <NavigationMenu.Item>
    <NavigationMenu.Content render={<Content />}></NavigationMenu.Content>
  </NavigationMenu.Item>
  <NavigationMenu.Item>
    <NavigationMenu.Content render={<Content />}></NavigationMenu.Content>
  </NavigationMenu.Item>
</NavigationMenu.List>;
```

## TypeScript Props Interface

**CRITICAL:** When creating wrapper components around Base UI primitives, NEVER duplicate props that are already provided by the Base UI component.

### ❌ Incorrect - Duplicating Base UI Props

```tsx
import { PreviewCard } from "@base-ui-components/react/preview-card";

// ❌ BAD: Manually duplicating delay, closeDelay, defaultOpen, etc.
export interface CardPreview01Props {
  trigger: React.ReactNode;
  href: string;
  delay?: number; // Already in PreviewCard.Root.Props
  closeDelay?: number; // Already in PreviewCard.Root.Props
  defaultOpen?: boolean; // Already in PreviewCard.Root.Props
  open?: boolean; // Already in PreviewCard.Root.Props
  onOpenChange?: (open: boolean) => void; // Already in PreviewCard.Root.Props
}
```

### ✅ Correct - Extending Base UI Props

```tsx
import { PreviewCard } from "@base-ui-components/react/preview-card";

// ✅ GOOD: Extend the Base UI component props
export interface CardPreview01Props extends PreviewCard.Root.Props {
  trigger: React.ReactNode;
  href: string;
  imageSrc: string;
  imageAlt: string;
  heading: string;
  description: string;
}

export function CardPreview01({
  trigger,
  href,
  imageSrc,
  imageAlt,
  heading,
  description,
  ...props // This spreads all Base UI props (delay, closeDelay, defaultOpen, etc.)
}: CardPreview01Props) {
  return (
    <PreviewCard.Root {...props}>{/* component content */}</PreviewCard.Root>
  );
}
```

### Key Benefits

1. **Type Safety**: Automatically get all Base UI prop types without manual maintenance
2. **Future-Proof**: New Base UI props automatically available in your component
3. **No Duplication**: Single source of truth for prop definitions
4. **Better DX**: TypeScript autocomplete shows all available props

### When to Define Custom Props

Only define props that are:

- Specific to your wrapper component (like `imageSrc`, `heading`)
- Not part of the underlying Base UI component
- Required for your custom implementation logic