diff --git a/backend/migrations/20260716_01_chat_messages_workflow.sql b/backend/migrations/20260716_01_chat_messages_workflow.sql
new file mode 100644
index 0000000..618aa09
--- /dev/null
+++ b/backend/migrations/20260716_01_chat_messages_workflow.sql
@@ -0,0 +1,12 @@
+-- Add chat_messages.workflow.
+--
+-- The app persists a `workflow` field on user messages
+-- (backend/src/routes/chat.ts, projectChat.ts) and reads it back when rendering
+-- chat history (frontend ChatView -> UserMessage, to show which workflow the
+-- message was sent under). The column was referenced in code but never created
+-- by schema.sql or any migration, so every user-message insert failed with
+-- PostgREST PGRST204 ("Could not find the 'workflow' column") and was dropped
+-- silently — user prompts vanished on reload while the assistant reply
+-- persisted. Mirrors the existing content/files jsonb columns.
+alter table public.chat_messages
+  add column if not exists workflow jsonb;
diff --git a/backend/schema.sql b/backend/schema.sql
index 5e48fa5..e2515d2 100644
--- a/backend/schema.sql
+++ b/backend/schema.sql
@@ -524,6 +524,7 @@ create table if not exists public.chat_messages (
   role text not null,
   content jsonb,
   files jsonb,
+  workflow jsonb,
   citations jsonb,
   created_at timestamptz not null default now()
 );