diff --git a/references/ai-chat/package.json b/references/ai-chat/package.json
index 737b71b0b..45071838a 100644
--- a/references/ai-chat/package.json
+++ b/references/ai-chat/package.json
@@ -10,6 +10,7 @@
     "db:migrate": "prisma migrate dev",
     "db:push": "prisma db push",
     "db:generate": "prisma generate",
+    "db:reset:chats": "prisma db execute --file prisma/reset-chats.sql",
     "test": "vitest"
   },
   "dependencies": {
diff --git a/references/ai-chat/prisma/reset-chats.sql b/references/ai-chat/prisma/reset-chats.sql
new file mode 100644
index 000000000..06363e733
--- /dev/null
+++ b/references/ai-chat/prisma/reset-chats.sql
@@ -0,0 +1,7 @@
+-- Wipe customer-side chat state for a fresh smoke-test slate.
+-- Run via `pnpm run db:reset:chats`.
+-- Leaves User rows intact (they're upserted by onPreload/onChatStart),
+-- but clears every Chat + ChatSession so a chatId from one target
+-- (test cloud / local) can't carry stale session/PAT/lastEventId state
+-- into the other.
+TRUNCATE "Chat", "ChatSession";