Help and FAQ

Shopify only, on any Shopify plan. One app install per store. Companies with more than one store are set up with us on the Direct customer plan: one workspace with several stores, people with roles, invoiced directly. Write to info@moststack.com.

A setup wizard of at most five steps asks what your store does: sell suppliers' products, supply other stores, or both. Then it walks you through your first supplier (a link, an upload, a sample of the supplier's email, or an invite code from a supplier who uses MostStack), shows the column mapping in a preview, runs the first import, shows the first sync in preview, and lets you switch it live when it looks right. A store that only supplies other stores creates an invite instead and waits for the partner to connect.

No. Every sync starts in preview: it shows what would change and changes nothing. Your stock only moves once you switch a sync live. Prices are never touched by a sync.

MostStack runs inside the Shopify admin as an app, and the full workspace at inventory.moststack.com opens from the app already signed in, with no separate login. Anything that leaves the app says so: an Edit in workspace or Open full workspace link opens that exact page in a new tab, and when you come back the app reads the page again so it shows what you changed.

In the app: the setup wizard, the overview (setup guide, stock updates per day, health of every supplier and sync, notices, plan and usage), suppliers and syncs with on/off switches and Import now, Run and Switch live, sharing for suppliers, plans, notices and help articles.

In the full workspace: every supplier setting (file location, column mapping, quantity words, price and cost rules, schedule, safety thresholds), every sync setting (location, matching, stock rules, schedule, metafields), the full history with CSV exports, the products explorer, adding new products, connections (FTP and SFTP servers, Google Drive, the email inbox, other Shopify stores) and settings such as time zone, retries and email alerts.

No. Suppliers keep sending files the way they do today and MostStack reads them. Only a supplier who wants to share stock through MostStack installs the app themselves, on the free plan.

The app is in English. Prices are used as the supplier gives them; cost rules are set per store.

• A link, including Google Sheets and Google Drive links
• An upload
• An emailed attachment, matched by sender, subject and file name
• A file on an FTP, FTPS or SFTP server: a fixed file, or the newest file matching a pattern
• A Google Drive file
• A supplier's API
• Another Shopify store
• A partner invite: a supplier who shares through MostStack

Connections are made while adding a supplier: when the file needs a Google account, a server, a store or an API key that isn't connected yet, the File step offers to connect one right there. FTP, SFTP, Google Drive and API suppliers are added in the full workspace, not in the app's wizard.

Yes, in the full workspace. The key or login is kept in an API key connection, encrypted and never shown again: a key in a header, a bearer token, a user name and password, a key in the address, or an OAuth client ID and secret. Open APIs need no key. The supplier holds the request (address, GET or POST, parameters, headers, where the products are in the answer) and the paging (page numbers, offset, a cursor or a next-page link, up to 1,000 pages). Pages are joined into one product list. JSON answers are paged; XML or CSV answers are read as one file.

CSV and TXT with any separator and encoding, Excel XLSX and old XLS (with a worksheet picker), XML, JSON, and ZIP archives containing any of these. Supplier APIs answer in JSON (paged) or XML. PDF price lists and invoices are read by AI when you add products to the store.

As often as every 15 minutes, up to once a day, at set times, or only by hand. Emailed files import when the email arrives. Unchanged files are skipped without being downloaded, and cost nothing against your plan.

Yes. Each store has a private MostStack email address. Forward the supplier's emails there, or set a rule in your mailbox, and MostStack imports the attachment when it arrives. Forwarded emails count as the original supplier's, however they reach the store: forwarded by hand from Gmail, Outlook, Apple Mail or Thunderbird, forwarded as an attachment, or forwarded automatically by a rule. So an email supplier is set up with the supplier's own address, and received emails show "from the supplier · forwarded by you".

Yes, like any other file. When you add products from it, descriptions, images, variants and details come along. If the supplier uses MostStack, ask them for an invite code instead: the supplier then arrives fully set up, refreshes every hour, and no credentials change hands.

Columns are recognised automatically and you check the mapping in a preview before the first import: SKU, barcode, name, brand, quantity, next delivery, cost, price, RRP and so on. The mapping can be changed any time in the full workspace.

Quantities like "10+", "in stock" or "few left" become numbers; a word MostStack hasn't seen before is flagged so you teach it once. Barcodes are normalised to GTIN and checked, duplicate rows are dropped, prices in any decimal style are read, and delivery dates are understood.

Safety checks stop the import, changing nothing, when the file is empty, much smaller than last time, or would remove too many products. You get a notice, and the import waits until you say "import anyway". Your stock is untouched.

At the next live sync their stock at that location goes to 0, because the supplier no longer has them. If too many products disappear at once, the import stops instead and waits for you.

Failed imports are retried (a workspace setting). You get a notice, and optionally an email, when an import fails or when a supplier hasn't updated for a while.

Yes. The full workspace keeps every import and sync run, and every product has its own history. A supplier product shows its stock in the supplier's file over the last 30 days as a chart, then every file change, one line each. A store variant shows when a sync last checked it, its stock in Shopify over 30 days, and every stock change syncs sent or failed to send, each linking to its sync run. The Store products list shows each variant's supplier and when it was last checked or changed. How far back history goes depends on the plan. Lists export to CSV.

A sync sends one supplier's quantities to one location of your store, matched by SKU (barcode as an option). It starts in preview, which shows what would change; when you switch it live it runs straight after every import of that supplier, also after an Import now or an upload while you watch, and, if you want, on its own timer. Only differences are sent.

Import and Shopify are two steps, shown as such: the supplier's page says "Imported", then whether its syncs have sent that stock to Shopify ("Up to date since …", "updating Shopify…", or what failed), and a sync's page says whether it has sent the supplier's latest import yet.

Multiply, keep a buffer back, cap at a maximum, and different rules per brand. Products gone from the file go to 0. Stock rules are included from the Operations plan up.

No. Syncs write stock quantities only. Prices, compare-at prices and cost are used only when you add new products from a supplier, and those are created as drafts for you to check.

Each sync writes one location. When two syncs write the same SKU, the one that runs last wins, and the workspace reports which one that was.

A sync stops, with a notice, when too many products would drop to 0 at once. Switch it back to preview, check the file, and run it again when you're sure.

Yes, as optional metafields on each variant: supplier stock, next delivery date, supplier name and SKU, and last update. Included from the Operations plan up.

In the full workspace, from a supplier's products that aren't in your store yet, or from a file or PDF price list or invoice read by AI. Prices are worked out by rules: start from the price or the RRP, add or take off a percentage, add or remove VAT, round to the cent or a price ending, and set the compare-at price. Products are created as drafts. From another Shopify store, including a partner, descriptions, images, variants and details are copied too.

This needs the store's permission to create products, which Shopify asks for once in the admin. Included from the Operations plan up.

A supplier with its own Shopify store (a brand, distributor or wholesaler) shares its stock with the stores it supplies. You create an invite code per partner; the partner enters it in their MostStack and your store arrives as a supplier, fully set up and refreshed every hour. Your stock is read with your own store access, so the partner never gets credentials. Sharing is free.

• Products: all by default, or only products matching conditions by brand, collection, tag or product type: any value within a condition, and all conditions (or, by choice, any); plus "leave out" conditions built the same way.
• Stock: from chosen locations, added up (the choice appears when the store has more than one); exact quantities, or exact up to a limit ("5+" shows as 5).
• The partner's cost: rules checked top to bottom, first match wins, per brand or collection: don't share, our cost, our cost plus a percentage, or a percentage off the compare-at price; then a default. Each rule shows how many shared products it covers, and the default how many fall to it.

Terms can be changed any time and apply at the next refresh.

The Sharing page lists your invites, or shows one Create invite button when there are none. Creating or editing an invite opens its own page. Duplicate on an invite's page starts a new invite from its terms, and End sharing is at the bottom of that page.

Yes. The preview shows counts, a sample with the partner's stock and cost, and products without a cost. When you narrow a running share you're warned, because those products go to 0 at the partner.

What's shared and how, before connecting, but never your margins.

End the share. It stops immediately.

No. Sharing is free on every plan, and it doesn't use the supplier's own product checks.

Billed through Shopify on your store's bill, monthly, with a 14-day free trial on paid plans.

• Free, $0: 1 supplier switched on, 200k product checks a month, 7 days of stock history. Share stock with any number of partner stores and choose what's shared, the stock detail and the partner cost; try importing one supplier.
• Essentials, $49 a month: 3 suppliers, 1M product checks, 30 days of stock history. Imports from links, uploads, email, FTP, Google Drive and APIs; stock syncs with preview; safety checks; email alerts.
• Operations, $129 a month: 10 suppliers, 5M product checks, 90 days of stock history. Everything in Essentials, stock rules, adding supplier products with price rules, supplier metafields.
• Network, $299 a month: 25 suppliers, 25M product checks, 1 year of stock history. Everything in Operations, several locations, priority support.

Beyond Network, a private plan by agreement: info@moststack.com. Stores set up with us outside the App Store are invoiced directly, without limits and with full stock history.

One supplier product read from a file that changed, plus one store variant a sync compares. Unchanged files cost nothing, so frequent schedules are free while the file stays the same. Counts reset on the 1st of each month (UTC).

Nothing stops. Scheduled imports and re-checks run at most every 6 hours until the month ends, and running by hand always works. You get notices at 80% and 100%.

Suppliers count when they are switched on. More can stay set up, switched off; a switched-off supplier keeps its settings but doesn't import at all, not by hand either. To switch one on, switch another off.

Upgrading applies straight away, with no re-setup. Downgrading keeps everything set up; if more suppliers are on than the new plan includes, the ones that imported most recently stay on and you're told which were switched off. Cancel any time by changing plan or uninstalling.

Stock history (the product charts and change lists) is kept about 400 days for every store; your plan sets how far back it's shown: 7 days on Free, 30 on Essentials, 90 on Operations, 1 year on Network, and all of it for direct customers. Chart periods are 7, 30 and 90 days and 1 year within that. Upgrading shows older history straight away; downgrading only hides it. Import and sync run lists and notices aren't limited.

Not yet. For stores beyond the Network plan we set up a private plan by agreement.

To read products, read and write inventory, and read locations. Permission to create products is asked for separately, once, the first time you add products from a supplier. MostStack never reads orders or customer data.

Server passwords and API keys are encrypted and never shown again. Partner shares never hand over store access. MostStack doesn't read or store customer or order data. See the privacy policy.

Imports and syncs stop and MostStack's access to your store is removed. Your set-up is kept so a reinstall finds it again. To have it deleted, write to the address in the privacy policy.