BEGIN;

ALTER TABLE models DROP CONSTRAINT IF EXISTS models_text_billing_mode_check;
ALTER TABLE models DROP COLUMN IF EXISTS max_output_tokens;
ALTER TABLE models ADD CONSTRAINT models_text_billing_mode_check CHECK (
    (model_type = 'text' AND text_billing_mode IN ('per_request', 'per_token'))
    OR (model_type <> 'text' AND text_billing_mode IS NULL)
);

COMMIT;