Chat Backend API edge cases handled (#472)

backend/alembic/versions/767f1c2a00eb_count_chat_tokens.py

@@ -0,0 +1,26 @@
+"""Count Chat Tokens
+
+Revision ID: 767f1c2a00eb
+Revises: dba7f71618f5
+Create Date: 2023-09-21 10:03:21.509899
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "767f1c2a00eb"
+down_revision = "dba7f71618f5"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "chat_message", sa.Column("token_count", sa.Integer(), nullable=False)
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("chat_message", "token_count")