diff --git a/tools/server/webui/src/lib/types/database.d.ts b/tools/server/webui/src/lib/types/database.d.ts
index 52732229ca..927de3cb74 100644
--- a/tools/server/webui/src/lib/types/database.d.ts
+++ b/tools/server/webui/src/lib/types/database.d.ts
@@ -77,6 +77,9 @@ export interface DatabaseMessage {
 	role: ChatRole;
 	content: string;
 	parent: string | null;
+	/**
+	 * @deprecated - left for backward compatibility
+	 */
 	thinking?: string;
 	toolCalls?: string;
 	children: string[];