# Supplier Update Guard — user guide

SUG-001 1.0.0 · Works with Shopify product CSV exports

The tool reviews existing variant prices only. No store connection, inventory changes, product creation/deletion, payments or accounts. Your input files stay in this tab's memory; outputs download locally. Clear the session or close the tab after use. No actual file rows are persisted. The site contact form is separate and server-stored: never attach or paste your customer CSV there.

## Review workflow
1. Export a fresh full product CSV from your own Shopify store. Keep an untouched backup outside SUG. Use complete product groups, never a manually shortened variant set: SUG cannot detect omitted variants or changes made in the live store after export.
2. Choose Shopify and supplier UTF-8 files. Comma, semicolon or tab detection is a suggestion: confirm the two delimiters before parsing. Limits: 15 MB / 50,000 variants for Shopify; 25 MB / 100,000 rows for supplier; 1 MB per cell, 1,024 characters per header, 256 columns. Unsupported encoding/malformed data stops processing. Output above 15 MB is blocked: export a smaller complete product selection.
3. Map supplier SKU/value and optional cost/currency/notes. Select direct price, markup on cost, or target gross margin; explicitly choose store base currency and supplier decimal separator. Thousands separators and FX are unsupported. Supported: USD/EUR/GBP/CAD/AUD/CHF (2 decimals), JPY (0), KWD (3). Decimal rounding is midpoint away from zero.
4. Calculate. SKUs are exact case-sensitive strings with surrounding whitespace removed only for lookup. Unique case-insensitive lookup is optional. Leading zeros survive. Duplicate SKU, missing identity, invalid sibling price, linked metafield options, unit pricing and unsafe native formula-looking fields fail closed. Correct inputs and recompute blocked rows. No automatic or fuzzy match.
5. Review rounded old/proposed prices, deltas, costs, gross margin before fees/taxes/shipping/discounts and risk reasons. Nothing is approved by default. Approve rows individually; high-risk rows cannot be bulk-approved (35% changes, 20% drops, below-cost/low-margin/high prices or zero original price). Confirm low-risk filtered bulk approval. Overrides require a validated price and reason, recompute risks and revoke approval. Changing any rule/mapping discards approvals and downloads.
6. Read and acknowledge these backup/import risks. Generate and download all four files. Candidate/rollback are reparsed and compared with original handle/options/complete variant sets before download. The summary contains local input SHA-256 hashes, settings, row references, risk/decision history and counts, not original CSV contents.

## The four files
Products using unit pricing are excluded: a price-only Shopify import can disable unit-price display even when its columns are omitted. This blocks the complete product, including otherwise unchanged siblings. Update those products directly in Shopify. Keep the full fresh export; never remove unit-price columns or values to bypass the guard.

- `shopify-price-update-YYYYMMDD.csv`: file for native Shopify product CSV import. Catalog field intended to change: Price only. Handle/title/option fields preserve identity. Full variant groups are included for affected products; unchanged siblings retain original prices; other products are omitted. SKU is not an import identity and is not included.
- `price-changes-YYYYMMDD.csv`: human review/audit ONLY; formula-looking values are prefixed with an apostrophe for spreadsheet safety. Never import this into Shopify.
- `rollback-prices-YYYYMMDD.csv`: same candidate schema with original prices for affected products.
- `review-summary-YYYYMMDD.json`: local audit metadata, schema 1.0, app version, hashes, settings and row-level decisions. Keep with your source backup and reports.

## Import and inspection
1. Keep your untouched full export from step 1 as the backup. Do not edit handles, options or candidate values in Excel. Missing/changed options can delete/recreate variants; blank included columns can erase fields.
2. Import one small product first with the official **Overwrite products with matching handles** option. Inspect Shopify's import preview. Cancel if it suggests new products/variants, changed options or any unintended fields.
3. Check that product in Shopify admin: only the approved price should differ, with its siblings, options, images, inventory and status unchanged. Then import the full candidate the same way.
4. To undo, inspect the rollback file and import it the same way. Re-export and compare prices with your backup.

Native CSV rollback is best-effort, not a transaction rollback or full backup restoration. It restores candidate prices only; later admin changes can complicate recovery. Keep your untouched full store export and independent inventory/media backups.

## Recovery and support
Cancellation produces no partial completed review. Clear session and reselect files after errors/reload. Close the tab on shared computers. The free demo reviews the first 10 supplier rows and creates no download files; the full version has no such limit. Report version, browser, failure category and synthetic reproduction via https://blznworks.com/contact?topic=product — omit customer CSV rows, SKUs and filenames. Blue Horizen Technology, Armenia. License, support and refund terms are those accepted at checkout: https://blznworks.com/terms

Official sources checked 2026-10-14:
- https://help.shopify.com/en/manual/products/import-export/using-csv
- https://help.shopify.com/en/manual/products/import-export/import-products