Sanity V3 custom checkbox component error with part: imports

The issue you're encountering is because you're using Sanity Studio v2 syntax in what appears to be a v3 project. The imports from part:@sanity/form-builder and part:@sanity/components don't exist in Studio v3 - these were the v2 APIs.

Here's how to create a custom checkbox input component for Sanity Studio v3:

import React from "react";
import { set, unset } from "sanity";
import { Stack, Checkbox } from "@sanity/ui";

const CheckboxComponent = React.forwardRef((props, ref) => {
  const { elementProps, onChange, value = false } = props;
  
  const handleChange = React.useCallback(
    (event) => {
      const isChecked = event.currentTarget.checked;
      onChange(isChecked ? set(isChecked) : unset());
    },
    [onChange]
  );

  return (
    <Stack space={3}>
      <Checkbox
        {...elementProps}
        ref={ref}
        checked={value}
        onChange={handleChange}
      />
    </Stack>
  );
});

export default CheckboxComponent;

Then in your schema, use it like this:

{
  name: 'myCheckboxField',
  type: 'boolean',
  components: {
    input: CheckboxComponent
  }
}

Key differences from v2 to v3:

1. No more part: imports - Import directly from sanity and @sanity/ui
2. PatchEvent is gone - Just use set() and unset() directly from the sanity package
3. No FormField wrapper needed - Studio v3 handles labels/descriptions automatically
4. Props structure changed - You get elementProps, onChange, value directly
5. Schema integration - Use components.input property instead of inputComponent

For a complete guide on creating custom input components in v3, check out this official guide. If you're migrating existing v2 components, the migration guide has detailed information on all the API changes.