Use the server-side workflow action: Validate CSV rows.
Key inputs:
- csv_text: the CSV text to check
- validation_rules: one rule per line, for example sku|required|unique or quantity|required|type=number|min=0
- required_columns: comma-separated required headers
- unique_columns: comma-separated columns that must be unique
- existing_values: static reference lists such as companies=Acme Ltd,Example Co
- delimiter: auto, comma, semicolon, tab, or pipe

Read can_import before running any database import. If can_import is no, show error_message, row_error_messages, or row_errors_json to the user.

CSV Guard validates only. It does not upload files, write database records, call external APIs, or sync spreadsheets.

Demo app run mode:
https://csv-guard-demo.bubbleapps.io/version-test

Demo app editor:
https://bubble.io/page?id=csv-guard-demo&tab=Design&name=index