From 2ce11799b0caa18f568de5caae85b3893b24ad2a Mon Sep 17 00:00:00 2001
From: Moritz Heckmann <moritz.heckmann@datavisyn.io>
Date: Fri, 19 Jun 2026 09:55:41 +0200
Subject: [PATCH] Added index to getGroupingValue

---
 .../src/features/column-grouping/columnGroupingFeature.types.ts | 2 +-
 .../src/features/column-grouping/columnGroupingFeature.utils.ts | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/table-core/src/features/column-grouping/columnGroupingFeature.types.ts b/packages/table-core/src/features/column-grouping/columnGroupingFeature.types.ts
index c376f378fa..a39daad78f 100644
--- a/packages/table-core/src/features/column-grouping/columnGroupingFeature.types.ts
+++ b/packages/table-core/src/features/column-grouping/columnGroupingFeature.types.ts
@@ -89,7 +89,7 @@ export interface ColumnDef_ColumnGrouping<
   /**
    * Specify a value to be used for grouping rows on this column. If this option is not specified, the value derived from `accessorKey` / `accessorFn` will be used instead.
    */
-  getGroupingValue?: (row: TData) => any
+  getGroupingValue?: (row: TData, index: number) => any
 }
 
 export interface Column_ColumnGrouping<
diff --git a/packages/table-core/src/features/column-grouping/columnGroupingFeature.utils.ts b/packages/table-core/src/features/column-grouping/columnGroupingFeature.utils.ts
index 7b96c2ceac..1ac6af6a26 100644
--- a/packages/table-core/src/features/column-grouping/columnGroupingFeature.utils.ts
+++ b/packages/table-core/src/features/column-grouping/columnGroupingFeature.utils.ts
@@ -284,6 +284,7 @@ export function row_getGroupingValue<
   if (row._groupingValuesCache) {
     row._groupingValuesCache[columnId] = column.columnDef.getGroupingValue(
       row.original,
+      row.index,
     )
   }