diff --git a/.changeset/late-falcons-scream.md b/.changeset/late-falcons-scream.md
new file mode 100644
index 0000000..096e101
--- /dev/null
+++ b/.changeset/late-falcons-scream.md
@@ -0,0 +1,5 @@
+---
+'@openai/chatkit': minor
+---
+
+Add `border` prop to Card widgets
diff --git a/packages/chatkit/types/widgets.d.ts b/packages/chatkit/types/widgets.d.ts
index 2d8859a..6045c4b 100644
--- a/packages/chatkit/types/widgets.d.ts
+++ b/packages/chatkit/types/widgets.d.ts
@@ -42,6 +42,7 @@ export type Card = {
   asForm?: boolean;
   children: WidgetComponent[];
   background?: string | ThemeColor;
+  border?: number | Border | Borders;
   size?: 'sm' | 'md' | 'lg' | 'full';
   padding?: number | string | Spacing;
   status?: WidgetStatus;