Zentra is a functional web app for auditing bounded datasets and exploring public-data workflows compatible with Google Sheets™. After signing in through secure single sign-on, choose Audit Sheet Dataset, load the reviewer-safe sample, and run the local browser audit. Zentra reports rows, columns, empty cells, duplicates, header issues, irregular row widths, mixed value types, and findings. No Zentra password, subscription, allowlisting, or API token is required for this workflow. Four local workflows are free. Optional datasets have product-specific prices determined by Zentra and are purchased through linked external marketplaces. Optional Apify-backed workflows use the user’s own Apify account and may incur charges billed directly by Apify. Zentra Foundry has no direct checkout and does not collect payments. Zentra does not guarantee business, legal, compliance, revenue, ratings, or marketplace outcomes. Review-safe sample data is synthetic and public-safe. Google Sheets™ is a trademark of Google LLC.