From b56d24ea3e7111c5fa34167a528f0f07fe22e32c Mon Sep 17 00:00:00 2001
From: Nilay <118994073+NilayYadav@users.noreply.github.com>
Date: Sun, 28 Jun 2026 16:46:03 +0530
Subject: [PATCH] Studio: cascade user message deletion to include assistant
 reply (#6720)

* cascade user message deletion to include assistant reply

* Fix comment typo in delete-thread-message

---------

Co-authored-by: Daniel Han <danielhanchen@gmail.com>
---
 .../chat/utils/delete-thread-message.ts       | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/studio/frontend/src/features/chat/utils/delete-thread-message.ts b/studio/frontend/src/features/chat/utils/delete-thread-message.ts
index 3b439eb779..bea5a63ea7 100644
--- a/studio/frontend/src/features/chat/utils/delete-thread-message.ts
+++ b/studio/frontend/src/features/chat/utils/delete-thread-message.ts
@@ -112,7 +112,26 @@ export async function deleteThreadMessage(args: {
   const exported = thread.export();
   const repo = new MessageRepository();
   repo.import(exported);
+
+  const target = exported.messages.find(
+    ({ message }) => message.id === messageId,
+  );
+  const assistantReplyIds =
+    target?.message.role === "user"
+      ? exported.messages
+          .filter(
+            ({ parentId, message }) =>
+              parentId === messageId && message.role === "assistant",
+          )
+          .map(({ message }) => message.id)
+      : [];
+
+  // Delete the prompt first; that relinks its replies up to the prompt's parent
   repo.deleteMessage(messageId);
+  for (const replyId of assistantReplyIds) {
+    repo.deleteMessage(replyId);
+  }
+
   const next = repo.export();
   if (remoteId) {
     await syncExportedRepositoryToBackend(remoteId, next, {