Used a spread on the path.

src/hooks/useRows.js

@@ -26,6 +26,7 @@ export const useRows = props => {
       const row = {
         original,
         index: i,
+        path: [i], // used to create a key for each row even if not nested
         subRows,
         depth,
         cells: [{}] // This is a dummy cell

src/hooks/useSimpleLayout.js

@@ -0,0 +1,37 @@
+
+export const useSimpleLayout = props => {
+  const {
+    hooks: {
+      columns: columnsHooks,
+      getHeaderProps,
+      getCellProps
+    }
+  } = props
+
+  columnsHooks.push((columns, api) => {
+    columns.forEach(column => {
+      column.visible =
+        typeof column.show === 'function' ? column.show(api) : !!column.show
+    })
+
+    getHeaderProps.push(column => ({
+      style: {
+        boxSizing: 'border-box',
+        width: column.width !== undefined ? `${column.width}px` : 'auto'
+      }
+    }))
+
+    getCellProps.push(cell => {
+      return {
+        style: {
+          boxSizing: 'border-box',
+          width: cell.column.width !== undefined ? `${cell.column.width}px` : 'auto'
+        }
+      }
+    })
+
+    return columns
+  })
+
+  return props
+}

src/hooks/useTable.js

@@ -143,7 +143,7 @@ export const useTable = (props, ...plugins) => {
     const { path } = row
     row.getRowProps = props =>
       mergeProps(
-        { key: ['row', path].join('_') },
+        { key: ['row', ...path].join('_') },
         applyHooks(api.hooks.getRowProps, row, api),
         props
       )

src/index.js

@@ -1,6 +1,7 @@
 export { useTable } from './hooks/useTable'
 export { useColumns } from './hooks/useColumns'
 export { useRows } from './hooks/useRows'
+export { useSimpleLayout } from './hooks/useSimpleLayout'
 export { useExpanded } from './hooks/useExpanded'
 export { useFilters } from './hooks/useFilters'
 export { useGroupBy } from './hooks/useGroupBy'