# Field extension API reference

Access our API reference for common props for field extension.

```ts
function useFieldExtension(): FieldExtensionProps;

export interface FieldExtensionProps extends ExtensionPropsBase {
  // name of the field in the form (may differ from the field apiId, ie. for localized fields)
  name: string;

  // current locale on localized field
  locale?: string;

  // id of the current entry, null on a new entry.
  entryId: string | null;

  isTableCell: boolean;

  value: any;

  onBlur: <T extends HTMLElement = HTMLElement>(
    event?: FocusEvent<T>,
  ) => Promise<void>;

  onChange: <T extends HTMLElement = HTMLElement>(
    event: ChangeEvent<T> | any,
  ) => Promise<void>;

  onFocus: <T extends HTMLElement = HTMLElement>(
    event?: FocusEvent<T>,
  ) => Promise<void>;

  // @see https://final-form.org/classic-docs/react-final-form/types/FieldRenderProps
  meta: {
    active: boolean;
    error: any;
    touched: boolean;
  };

  // access to the form state and other form fields
  form: Form;

  // details about the current field
  field: {
    id: string;
    apiId: string;
    description: string | null;
    displayName: string;
    isList: boolean;
    isLocalized?: boolean;
    isRequired?: boolean;
    isUnique?: boolean;
    // true when in version or stage comparison view
    isPreview: boolean;
    type: FieldExtensionType;
  };

  // details about the current model
  model: Model;

  // configuration of the extension.
  extension: {
    config: Record<string, any>;
    fieldConfig: Record<string, any>;
    tableConfig: Record<string, any>;
  };

  // whether the field is currently in fullscreen mode
  isExpanded: boolean;
  // set fullscreen mode
  expand: (expand: boolean | ((isExpanded: boolean) => boolean)) => void;
}
```