diff --git a/backend/open_webui/migrations/versions/c49178636c78_add_chat_variables.py b/backend/open_webui/migrations/versions/c49178636c78_add_chat_variables.py
new file mode 100644
index 0000000000..7823f3867c
--- /dev/null
+++ b/backend/open_webui/migrations/versions/c49178636c78_add_chat_variables.py
@@ -0,0 +1,31 @@
+"""add chat variables
+
+Revision ID: c49178636c78
+Revises: 9a1b2c3d4e5f
+Create Date: 2026-07-23 23:33:45.497453
+
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+
+# revision identifiers, used by Alembic.
+revision: str = 'c49178636c78'
+down_revision: Union[str, None] = '9a1b2c3d4e5f'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+    inspector = sa.inspect(conn)
+    columns = [col['name'] for col in inspector.get_columns('chat')]
+
+    if 'variables' not in columns:
+        op.add_column('chat', sa.Column('variables', sa.JSON(), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column('chat', 'variables')