FTP, SFTP, REST, PromoStandards: The Four Ways Apparel Suppliers Hand You Data to Sell on Shopify

When you ask a SanMar rep how they share their catalog with Shopify stores, they will tell you it goes through "FTP." They might mean a folder of files on a server. They might mean an EDI feed. They might mean both. They will not draw you a diagram.

Meanwhile S&S Activewear's docs say the words "REST API." Cap America's docs talk about "PromoStandards." Augusta sends you a PDF and a spreadsheet on a Friday once a quarter. Each one is asking you to read its catalog in a different way.

You are a Shopify store owner, not an integration engineer. You don't need to learn EDI in three weeks. You do, however, need to know which of these four data shapes your supplier is in, what each one means for your store's day-to-day operations, and which integration apps know how to read it.

This article gives you that. It uses SanMar (US and Canada) as the running example for FTP — because SanMar is one of the largest apparel suppliers in North America, because almost every U.S. apparel store buys from SanMar at some point, and because their FTP feed is what most of the FTP world looks like. It then covers REST (S&S Activewear, AlphaBroder, JDS Industries), PromoStandards (Cap America, OTTO Cap, Goldstar, Atlantic Coast Cotton), SFTP/FTP-via-credentials (Edwards Garment, Scrub Authority), and no-credential / file-based (Augusta Sportswear, AS Colour, CHAMPRO, Decky, custom suppliers).

Running example used throughout the FTP and option-overview sections: Northside Print Co., a six-person screen-print and embroidery shop running a SanMar import for the first time. They want their store live by Friday. They have not retyped a CSV since 2022, and they would like to keep it that way.

Key Takeaways

• The decision — figure out which of four data shapes each of your suppliers exposes, and pick an app that reads each in its native shape (no CSV workarounds).
• The four shapes — FTP/SFTP (folder of files), REST API (live data connection), PromoStandards (a shared promo-industry format), and no-credential / file-based (the supplier's quarterly catalog drop).
• The fast answer for SanMar — FTP credentials from your SanMar rep + a Shopify app that natively reads SanMar's nightly feed. You'll be live this week.
• When each shape wins — FTP for big brand-led catalogs (SanMar, Edwards), REST for fast-moving distributors (S&S Activewear), PromoStandards for promo-channel suppliers (Cap America, OTTO, Goldstar, ACC), file-based for everything else (AS Colour, CHAMPRO, Decky, Augusta).
• Try it now — Install Supply Master free on the Shopify App Store (5.0★, top-rated for apparel-supplier integration in the U.S. and Canada) or email support@comstack.com and we'll set the SanMar feed up on your store.

Table of contents

• Why this matters more than the marketing pages let on
• The four data shapes, in plain English
• FTP and SFTP — the SanMar shape
• REST API — the S&S shape
• PromoStandards — the promo-industry shape
• No-credential / file-based — the seasonal-supplier shape
• Side-by-side: which shape does what
• How real stores choose
• Where Supply Master fits
• FAQ
• Try it on your store

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Why this matters more than the marketing pages let on

Most Shopify supplier apps say "we support SanMar, S&S, Alphabroder, Cap America, Augusta." That is true and useless. The marketing line tells you nothing about how the app reads each supplier — and the way an app reads a supplier determines whether your stock will be fresh, whether your prices will hold margin through a wholesale change, whether your orders will route the same day, and whether new colors of a Gildan 5000 show up before you have to chase them.

The four shapes below are the actual menu. Every reputable apparel supplier's data exposure falls into one of them. An app that handles your supplier in its native shape will be fast and reliable. An app that handles your supplier through a "CSV upload workaround" will be slow and brittle.

This article gives you the shape menu, what each shape means for your week, and which suppliers are in which shape — so when you compare apps, you compare them against the actual data path your store will run on.

The four data shapes, in plain English

Shape	What the supplier does	What you do	Typical refresh
FTP / SFTP (folder of files)	Drops a fresh stock-and-price file on a server every night	Get credentials from your supplier rep; the app reads the folder daily	Daily
REST API (live data connection)	Exposes a live "ask me anything" service that returns current data on demand	Get an API key; the app calls the API every few hours	Every few hours
PromoStandards (shared promo format)	Speaks a standard promo-industry language so apps can plug in once and read everyone	Get the right credential type; the app speaks the standard format	Daily to several times daily
No credential / file-based	Publishes a static catalog file on their site (or sends a PDF + spreadsheet)	The app re-reads the file on a schedule; no live feed	Quarterly to monthly

Each shape lands a different supplier in the same place — your Shopify catalog — but the trade-offs are real.

FTP and SFTP — the SanMar shape

The plain-English version. Your supplier maintains a folder on a server. Every night (or every morning, or several times a day) they drop a fresh file — usually a CSV or an EDI text file — into that folder. The file contains the latest stock counts, the latest wholesale prices, and any new colors and styles that came online overnight. An app like Supply Master logs into that folder on a schedule, downloads the file, parses it, and writes the new numbers into Shopify before your store opens the next day.

That folder-and-files setup is called FTP (or SFTP when the connection is encrypted, which all modern setups should be). Both letters stand for "file transfer protocol." Both work the same way for your purposes — the SFTP version just adds privacy on the wire.

Why suppliers like FTP. It's stable. It scales with massive catalogs (SanMar is somewhere in the 40,000+ SKU range; their nightly file moves it all without melting any servers). It puts the supplier in control of the refresh window — they generate the file once, and any number of integration apps can read the same file overnight.

What it means for your store. Stock and prices in Shopify are accurate as of the last drop. If SanMar drops the file at 11pm Eastern, your store opens Tuesday morning with Tuesday's numbers, not Monday's. New colors of a Port Authority L500 polo or a District DT104 tee will appear in your filtered catalog the day after they go live at SanMar.

The trade-off: real-time stock changes during the day are not reflected. If a SanMar warehouse runs out of Heather Grey size XL at 2pm, your Shopify store will show "in stock" until the next file drop. Most apparel stores accept this trade-off because the cost of nightly refresh is far lower than the cost of running a real-time API integration of SanMar's catalog scale.

SanMar specifically. SanMar (US) and SanMar Canada both expose their catalogs over FTP / SFTP via an EDI account. Your SanMar rep issues an EDI account number; that account number gives the integration app permission to read the nightly catalog, stock, and price files. SanMar's product file also includes spec data — fabric, weight, care, country of origin — which is why decorators love SanMar's depth: a single supplier's feed gives you everything to build full Shopify product pages without manual writing.

What you do to set it up.

1. Email your SanMar rep and ask for an EDI account (not just a customer account).
2. Once approved, give the EDI credentials to your integration app — usually username, password, and host fields on the supplier-edit screen.
3. Tell the app which slice of the SanMar catalog to import (brands, colors, sizes, price band).
4. Set the refresh cadence (daily is right for most stores).
5. Run the first sync. Walk away. Come back to a populated Shopify catalog.

For Northside Print Co., this end-to-end is usually a 30-minute task once the EDI credentials are in hand. The SanMar credentials approval can take a few business days; that is the bottleneck for most installs, not the app setup itself. See how to get your supplier credentials.

Other suppliers in the FTP shape. SanMar US, SanMar Canada, Edwards Garment, Scrub Authority. Each requires its own credential set; the underlying mechanic is the same.

REST API — the S&S shape

The plain-English version. Your supplier exposes a live "ask me anything" service. An app can ask "how many Bella+Canvas 3001 in Black size L do you have right now?" and get an answer in milliseconds, anytime. No file drops; the answer is always current.

That live-ask service is called a REST API ("API" is the live data connection your supplier provides; "REST" is just the modern style of API). The app authenticates with a key your supplier issues, makes the request, and receives a structured answer it can write into Shopify.

Why some suppliers like REST. It supports faster cadences for stores that need them. A pure dropshipper running thousands of orders a week wants stock counts measured in hours, not days. REST also makes order push easier — the same API the app reads from is usually the API it can write orders into. That's why S&S Activewear is the supplier where Supply Master can offer live order routing today.

What it means for your store. Stock and prices can refresh several times a day. Orders can route back to S&S the same hour they're placed in Shopify. New colors and styles propagate to your filtered catalog within hours, not next morning. The catalog feels live.

The trade-off: more moving parts. APIs occasionally throttle (a "slow down" signal from the supplier) when traffic spikes, and a well-built integration app needs to handle that gracefully. APIs also gate access more strictly — you'll go through an approval process to get the key, which can be faster or slower than getting EDI credentials depending on the supplier's process.

S&S Activewear specifically. S&S Activewear's REST API exposes the catalog (90,000+ SKUs across hundreds of brands), live stock per warehouse, real-time wholesale, and live order placement. Their U.S. footprint covers eight warehouses with 1-day shipping reach to 41 states. The combination of a live API + dense warehouse footprint is why so many pure dropshippers run on S&S as their primary supplier.

What you do to set it up.

1. Apply for an S&S Activewear web services account (the API tier of an S&S customer account).
2. Once approved, you get an API username, password, and customer number.
3. Give the credentials to your integration app on the supplier-edit screen.
4. Tell the app the catalog filter (brands, colors, sizes, price band) and the inventory mapping (combine, filter, or map per Shopify location — see Multi-warehouse inventory on Shopify: combine, filter, or map?).
5. Pick the order routing mode (auto / scheduled / manual / off).
6. Run the first sync.

Other suppliers in the REST shape. S&S Activewear, AlphaBroder, JDS Industries. Each issues its own API credentials; the integration app reads each one through the supplier-specific connector but with the same general mechanic.

PromoStandards — the promo-industry shape

The plain-English version. PromoStandards is a shared format used by promotional-product suppliers so that apps like ours can plug in once and read every supplier that follows the format. Instead of every promo supplier inventing their own data shape, the promo industry agreed on a standard — common product fields, common stock fields, common pricing fields, common ordering fields.

For your store, this means an integration app that "speaks PromoStandards" can read Cap America, OTTO Cap, Goldstar Pens, and Atlantic Coast Cotton through more or less the same connector. Your effort to add a fourth promo supplier is a credential file, not a brand-new integration.

Why suppliers like PromoStandards. It lets a small promo supplier reach hundreds of stores without building a custom integration per app. The promo industry has used this format since 2012, and the working group that maintains it lists the suppliers and apps that have certified connections — see promostandards.org/companies and the integrated suppliers list at psrestful.com/integrated-suppliers.

What it means for your store. Stock and prices typically refresh daily to several times daily, depending on the supplier's data update frequency. Catalog and image data is consistent across PromoStandards suppliers, which is helpful when you're running multi-supplier promo sets (e.g. a corporate-merch program with hats from Cap America, drinkware from a PromoStandards drinkware supplier, and pens from Goldstar). Order push capability varies by supplier — some PromoStandards suppliers expose order endpoints; others don't.

The trade-off: PromoStandards covers what's standardized, which is a lot but not everything. Catalog imagery quality varies by supplier. Decoration-related fields (imprint locations, colors) are part of the standard but not every supplier fills them in fully. For decorators who need rich decoration data, the supplier's depth in PromoStandards is worth checking before you commit.

The four PromoStandards suppliers most apparel-and-promo stores see.

• Cap America — caps, beanies, visors. PromoStandards-native. Their headwear catalog is one of the deepest in promo and pulls cleanly through the standard.
• OTTO Cap — caps and headwear. PromoStandards-native. Sister coverage to Cap America for shops that buy across both.
• Goldstar Pens — promotional pens, drinkware, accessories. PromoStandards-native. A common addition to a corporate-merch shop.
• Atlantic Coast Cotton (ACC) — apparel and accessories at promo pricing tiers. PromoStandards-native.

What you do to set it up.

1. Sign up for a wholesale account with the supplier (each one separately).
2. Request PromoStandards credentials — usually a customer number and API key or a similar pair.
3. Give the credentials to your integration app, which already speaks PromoStandards generically and just needs the per-supplier credential block.
4. Set up filtering, pricing, and order routing per supplier.
5. Run the first sync.

The setup time per PromoStandards supplier is usually shorter than for FTP or REST suppliers because the integration shape is shared.

No-credential / file-based — the seasonal-supplier shape

The plain-English version. Some apparel suppliers — especially seasonal, mid-size, or specialty ones — don't expose a live feed at all. They publish a quarterly catalog file on their public site, or they send their dealers a Dropbox link with a stock spreadsheet on the first of each month, or they hand you a PDF you turn into a CSV.

For your store, this means an integration app reads the published file on a schedule (or you upload it on a schedule) and writes it into Shopify. There are no live stock counts during the quarter; there are no live order endpoints; the supplier's view of "real-time" is "next quarter."

Why some suppliers stay file-based. Smaller catalogs, smaller engineering teams, and a buyer base that doesn't need minute-to-minute stock. A team-store operator who orders Augusta jerseys for a March-to-April baseball season doesn't need real-time stock — they place the season's order in late February and Augusta ships it in two waves.

What it means for your store. Stock and prices refresh on the supplier's catalog cadence, which is usually quarterly or monthly. New SKUs land when the next catalog file drops. There are no real-time order placements through the integration app; orders go through whatever ordering channel the supplier uses (often a dealer portal or a phone-and-email PO).

The trade-off: data freshness is the lowest of the four shapes. For seasonal suppliers, this is fine. For year-round suppliers, you don't want to live in this shape.

The five suppliers most apparel-and-promo stores see in this shape.

• Augusta Sportswear — uniforms, jerseys, athletic apparel. Augusta does have integration partners but their public-file model is widely used by smaller dealers.
• AS Colour US — premium blanks. AS Colour publishes a stock-and-price file dealers can read on a schedule.
• CHAMPRO Sports — team athletics, baseball/softball, football, soccer. Often published-file.
• Decky — caps, headwear, beanies. Often published-file or dealer-portal-driven.
• Custom suppliers — any supplier you maintain yourself in a structured spreadsheet that the integration app re-reads on a schedule. Use this for small specialty mills, white-label embroidery shops, or supplier relationships you can't put through a credential.

What you do to set it up.

1. Get the supplier's catalog file (download link, dealer portal, or your own structured spreadsheet for custom suppliers).
2. Give the file location (or upload schedule) to your integration app.
3. Set up filtering, pricing, and import frequency.
4. Re-upload or refresh on the supplier's natural cadence.

For custom suppliers, the Custom Supplier flow in Supply Master lets you maintain a spreadsheet (Google Sheets, Excel, CSV) on a known schema and have the app re-read it on a sync schedule. See the supported suppliers list for the live status of each named supplier above and the custom-supplier shape.

Side-by-side: which shape does what

Capability	FTP / SFTP	REST API	PromoStandards	No-credential / file
Stock refresh frequency	Daily	Every few hours	Daily to several times a day	Quarterly / monthly
Price refresh frequency	Daily	Daily to faster	Daily	Quarterly / monthly
Live order routing	Sometimes	Yes (where the supplier supports it)	Sometimes	Not via the integration
New SKUs propagate within	A day	Hours	A day	Next file
Setup bottleneck	Credential issuance from supplier rep	API key approval	PromoStandards credentials	Get the file
Plays well with massive catalogs	Yes	Yes (with throttling)	Yes	Yes (cadence permitting)
Suppliers in this shape (apparel & promo)	SanMar US, SanMar Canada, Edwards, Scrub Authority	S&S Activewear, AlphaBroder, JDS Industries	Cap America, OTTO Cap, Goldstar, ACC	Augusta, AS Colour US, CHAMPRO, Decky, custom

The categories are how integration apps think about supplier coverage. When you compare apps, ask: "Does this app handle my top supplier in its native shape — not via CSV workaround?" That single question filters most of the category.

How real stores choose

Northside Print Co. (multi-supplier decorator)

S&S for blanks (REST). SanMar for uniforms (FTP). Cap America for hats (PromoStandards).

They install Supply Master, connect S&S with their REST API account, connect SanMar with their EDI credentials, and connect Cap America with PromoStandards credentials. Three connection types. One app. One dashboard. Their Saturday mornings come back.

A pure S&S dropshipper

S&S only (REST). They want fast inventory loops because they live or die on stock freshness, and live order routing because their fulfillment story is "the customer pays at midnight, S&S ships at 6am."

They run S&S in REST, combine-warehouse inventory across all eight S&S warehouses, and auto order routing.

A youth-baseball team store

Augusta for uniforms (file-based) plus a hat supplier (file-based or PromoStandards depending on the shop's choice).

They run a custom-import flow for Augusta against the season's published file, set their pricing rules for jersey and hat markups, and turn off live order routing because they place one bulk PO at the close of the season's order window.

A healthcare-uniform retailer

One supplier, FTP shape, deep variant data. They run nightly FTP refresh, MAP-aware pricing rules so retail respects the brand floor, and manual order routing so stipend orders are reviewed before they go to the supplier.

Where Supply Master fits

Supply Master, the app this site is for, handles all four shapes natively:

• FTP / SFTP for SanMar US, SanMar Canada, Edwards, Scrub Authority, and other FTP-based apparel suppliers. EDI credentials in, nightly catalog and stock refresh out.
• REST API for S&S Activewear, AlphaBroder, JDS Industries. Live stock, fast price refresh, live order routing where the supplier supports it (today's live-order story is strongest on S&S).
• PromoStandards for Cap America, OTTO Cap, Goldstar, Atlantic Coast Cotton, and other PromoStandards-certified apparel and promo suppliers. One connector handles all of them.
• No-credential / file-based for Augusta, AS Colour, CHAMPRO, Decky, and custom suppliers — where you maintain a spreadsheet (Google Sheets, Excel, CSV) on a known schema and Supply Master re-reads it on a schedule.

Per-supplier capabilities — including which features are live for which supplier — live at supported suppliers and features. For credential setup, see how to get your supplier credentials.

What it does well today across the four shapes:

• One install, one dashboard, all four shapes simultaneously.
• Filtered catalog import per supplier (brand, color, size, price band).
• One-line Liquid price rules per supplier and per filter — see customizing fields with Liquid formulas.
• Combine / filter / map multi-warehouse inventory per supplier — see setting up inventory by warehouse location.
• Order routing (auto / scheduled / manual / off) per supplier where the supplier shape supports it.
• AI+ enrichment that rewrites supplier descriptions into clean SEO copy when you want it. See AI+ enriched product data.
• 5.0★ rating on the Shopify App Store; top-rated for apparel-supplier integration in the U.S. and Canada.
• Comstack engineers will set up your store on request — email support@comstack.com.

What it doesn't do (yet):

• Live order push for every PromoStandards supplier; current behavior is per-supplier and ranges from live order endpoints to manual / scheduled CSV order push.
• Decorator order consolidation (combining multiple Shopify orders into one PO to the supplier). Recommended workflow today is scheduled order routing with supplier-side consolidation; full in-app consolidation is on the roadmap.

FAQ

Will this work for SanMar?

Yes. SanMar (US and Canada) is FTP-shape. You'll need an EDI account from your SanMar rep. Once the credentials are issued, Supply Master reads SanMar's nightly catalog, stock, and price files automatically. Setup takes about 30 minutes once the credentials are in hand; the SanMar credential approval is the typical bottleneck.

Will this work for S&S?

Yes. S&S is REST-shape. You'll need a web-services account with S&S (the API tier of an S&S customer account). Once issued, Supply Master pulls live stock, refreshes prices, and routes orders back to S&S in your chosen mode (auto / scheduled / manual / off).

Will this work for Cap America, OTTO, Goldstar, or Atlantic Coast Cotton?

Yes. All four are PromoStandards-shape. You'll need PromoStandards credentials from the supplier (usually issued with your wholesale account). Supply Master speaks PromoStandards generically, so adding the second, third, or fourth promo supplier is a credential file, not a new integration.

What if I have more than one supplier in different shapes?

Most apparel stores do. Supply Master handles all four shapes simultaneously in one install. Northside Print Co. (running S&S REST + SanMar FTP + Cap America PromoStandards) is the typical multi-supplier shape, not the exception.

Do I need a developer to set this up?

No. Every shape above is set up through the Supply Master admin screens by the store owner. The hardest step is usually getting the supplier credentials — and the credential help doc walks you through each one.

How fast does each shape sync in practice?

Shape	Typical Supply Master cadence
FTP / SFTP	Daily (or your schedule)
REST API	Every few hours, configurable
PromoStandards	Daily, configurable per supplier
File-based	On the supplier's published-file cadence (quarterly / monthly)

Faster cadences are available on higher tiers and per-supplier capability. The base plan covers daily for most apparel stores.

What if my supplier isn't listed anywhere above?

Most major U.S. and Canadian apparel and promo suppliers fall into one of the four shapes. If yours doesn't, the custom supplier flow lets you maintain a structured spreadsheet (Google Sheets, Excel, CSV) on a known schema and have Supply Master re-read it on a schedule. Email support@comstack.com and we'll set the schema up with you.

What about Shopify's variant limits?

Modern Shopify supports up to 2,048 variants per product. Older apps that still cap at 100 variants will silently drop SanMar's larger style families. Supply Master writes to the modern variant ceiling; the legacy variant-splitting feature is available for stores still on the old cap. See variant splitting (legacy feature).

What does it cost?

Supply Master offers a free trial. Plan tiers scale with variant count, sync volume, and supplier count. Exact pricing is on the App Store listing.

What if my store keeps overselling regardless of which shape?

Read Why Shopify Stores Oversell Apparel — and What Inventory Actually Needs to Do and Multi-warehouse inventory on Shopify: combine, filter, or map?. Overselling is usually a sync-cadence problem, a multi-warehouse problem, or both — not a fundamental shape issue.

Try it on your store

Each shape is a different supplier's day. The right integration app reads each one in its native shape and writes the right number into Shopify before your store opens.

1. Install Supply Master free on the Shopify App Store — 5.0★, top-rated for apparel-supplier integration in the U.S. and Canada.
2. Or email support@comstack.com — a Comstack engineer will set up your SanMar EDI feed, your S&S REST connection, your PromoStandards suppliers, and your file-based supplier together, in one pass.

Comstack has been building integrations for apparel and promo suppliers since 2012. The shape menu above is the menu we've actually shipped — and the one we run on our own apparel store today.

Don't pick the app that lists the most logos. Pick the app that reads each of your suppliers in their native shape, on your sync cadence, with the order-routing mode your team can actually run.