Walmart Marketplace integration: selling on Walmart alongside Shopify and Amazon

Walmart is now the marketplace many Shopify and Amazon sellers look at next. Its own figures explain why: in the quarter to July 2026, Walmart U.S. reported more than 50% growth in marketplace net sales (Walmart, 20 August 2026). Adding Walmart without a Walmart Marketplace integration, though, means one more catalogue to keep up to date, one more stock count and one more order queue.

This guide is for sellers already on Shopify, Amazon or both who want to add Walmart without doubling their workload. It covers getting approved, the ready-made connectors from Shopify and Amazon, Walmart's own APIs, the choice between Walmart Fulfillment Services and Amazon's Multi-Channel Fulfillment, and when a custom integration is worth building. I build e-commerce automation and integrations on official APIs, so this is written from that angle.

Getting approved comes first

Walmart Marketplace is not open signup. You apply, Walmart reviews the business, and only an approved seller account can list products or generate API keys. Walmart's own seller page says there are "zero monthly or set up fees", with a referral fee charged on each sale (Walmart Marketplace).

Walmart does not publish one complete checklist on that page. Seller guides consistently mention a US business tax ID, a track record of selling online, and product identifiers (UPCs or GTINs) for what you plan to list. Treat those as likely requirements and confirm the current list when you apply. None of the integration work below can start until the account exists, so apply early.

Three ways to connect Walmart with Shopify and Amazon

Route	Best for	Watch out for
Shopify Marketplace Connect	Shopify as the hub, simple catalogue	US only for Walmart; per-order fee above a free allowance
Amazon's multichannel tools in Seller Central	Amazon as the hub, US sellers	Rolling out gradually; feature set still growing
Third-party or custom integration on Walmart's APIs	Your own rules, several warehouses, bundles, reporting	Costs more up front; someone has to maintain it

Shopify Marketplace Connect

Shopify's own app connects a store to Amazon, eBay, Walmart and Target Plus, and syncs listings, inventory, orders and tracking. For Walmart it is United States only, and you need a verified Walmart seller account before connecting (Shopify Help Center). Pricing is the first 50 synced orders a month free, then 1% per order, capped at $99 a month.

Amazon's multichannel tools

In September 2026 Amazon announced tools that let sellers connect eBay, Shopify, TikTok and Walmart accounts to Seller Central, import and link listings, edit a description once and have it update everywhere, and see and act on every order in one place, with fulfilment through Amazon a few clicks away (About Amazon). They are rolling out gradually to US sellers at no additional cost, so check whether your account has them yet.

Both options are good starting points if your setup matches what they expect. They get harder to live with when you have bundles, several warehouses with different rules, or Walmart-specific pricing.

The Walmart Marketplace APIs

Walmart's developer platform is the official route for everything else. A few points shape any Walmart Marketplace integration:

• Authentication. Sellers generate a Client ID and Client Secret in Walmart's Developer Portal and exchange them for access tokens, which are valid for 15 minutes. Apps connecting to other sellers' accounts use OAuth authorisation instead.
• Items go through feeds. New items and bulk updates are sent as feed files using Walmart's item spec (version 4.x), then submitted and published. Walmart says each of those two steps "typically takes a few hours", so a new listing is not live the moment you send it.
• Inventory can be updated per item or per ship node (warehouse), and read across nodes.
• Orders move through created, acknowledged, shipped and delivered. Acknowledging an order is required before shipping, and the API also handles cancellations and refunds per order line.
• Notifications. Walmart can push events, such as a new purchase order, to your endpoint, so the integration does not have to keep asking.
• A sandbox lets you create test items and simulate orders, deliveries and returns before touching your live account.

Rate limits

Walmart enforces limits per API with a token bucket, and returns a 429 error when you exceed them. The defaults vary widely (Walmart rate limiting). Reading orders allows 5,000 calls a minute, while shipping, cancelling or acknowledging order lines allows 60 a minute. Updating a single item's price is limited to 100 an hour, and bulk price feeds to 10 an hour. Stock updates allow 200 calls a minute. In practice that means price changes have to be batched into feeds, and order updates queued, rather than fired off one by one.

WFS, Multichannel Solutions or Amazon MCF

Fulfilment is the biggest decision when adding Walmart, because it decides where your stock lives.

• Walmart Fulfillment Services (WFS) stores your stock in Walmart's warehouses and ships Walmart.com orders.
• Walmart Multichannel Solutions uses that same WFS stock for orders from other channels. Walmart lists Amazon, eBay, Shein, Temu and TikTok Shop, shipped in unbranded packaging to addresses in the 50 states and Puerto Rico. You must be a WFS seller, and multi-box and big and bulky items are not currently eligible (Walmart Marketplace Learn). Orders can be added in Seller Center or sent through Walmart's Multichannel API.
• Amazon Multi-Channel Fulfillment works the other way round: since September 2025 Amazon has accepted Walmart Marketplace orders for fulfilment from FBA stock, also in unbranded packaging. Order fulfilment with Amazon MCF explains the routing.

Pick one pool as the main one for shared stock. If most of your sales are on Amazon, MCF for Walmart orders keeps everything in FBA. If Walmart grows to be the bigger channel, WFS with Multichannel Solutions can serve Amazon and Shopify orders instead. Some sellers use both, which is where an integration has to know exactly which units sit in which network.

Mapping listings from Shopify or Amazon to Walmart

Walmart's item spec has its own attributes per category and its own rules for grouping variants, so a Shopify product or Amazon listing rarely copies across untouched.

• Product identifiers. Keep a clean UPC or GTIN per variant before you start; seller guides list them as a requirement for most categories.
• Category attributes. Map each Shopify product type or Amazon product type you sell to a Walmart category and fill the attributes it requires.
• Variants. Check that sizes and colours group the way Walmart expects, rather than arriving as separate items.
• Prices. Decide whether Walmart prices follow Shopify or Amazon, or have their own rules, and remember the hourly limits on price updates.
• SKUs. Use the same SKU on every channel, with separate SKUs for stock held in WFS or FBA, so no count is ever mistaken for another.

When a custom Walmart Marketplace integration makes sense

A ready-made connector is the right first step for most sellers. Custom work earns its cost when:

• stock is shared across three or more channels and one system has to stay the master, as described in how to stop overselling across channels;
• bundles or kits need their stock calculated from components;
• orders must be routed between WFS, FBA, a 3PL and your own shelves by rules;
• Walmart-specific pricing has to follow its own logic within Walmart's update limits;
• reporting needs Walmart next to Shopify and Amazon in one place.

If you go custom, build it in this order: SKU clean-up, stock sync, order import with tracking back to Walmart, then listings and prices, then reports. Stock and order errors cost money daily; listing automation saves time once.

What a Walmart integration costs

Marketplace Connect and Amazon's tools have low or no direct cost; their price is in the rules they cannot express. Third-party connectors charge monthly fees.

For a custom build, connecting Walmart through its official API with one automation, such as importing Walmart orders into Shopify or a daily WFS stock report, fits my MVP plan for marketplace and ecommerce apps, from $2,500. Walmart, Shopify and Amazon with stock and orders kept in sync, plus a dashboard, is the Flexible plan, from $5,500. Repricing rules and AI-drafted listings you approve are in the Advanced plan, from $9,500. These are starting prices, and every project gets a fixed quote after a short brief: see the marketplace app plans.

FAQ

Does Walmart charge a monthly fee to sell on its marketplace?

Walmart says there are no monthly or setup fees to sell on Walmart Marketplace. Instead, it charges a referral fee on each sale, which varies by category; check Walmart's current fee table before pricing your products. Fulfilment through Walmart Fulfillment Services has its own fees on top. Integration tools are a separate cost: Shopify's Marketplace Connect, for example, is free for the first 50 synced orders a month and then charges per order.

Can Walmart Fulfillment Services ship my Shopify and Amazon orders?

Yes, through Walmart Multichannel Solutions, if you are already a WFS seller. It ships orders from other channels out of your WFS stock in unbranded packaging, to addresses in the 50 US states and Puerto Rico. Walmart's own pages name your website, Amazon, eBay, Shopify, Shein, Temu and TikTok Shop among the channels. Multi-box and big and bulky items are not currently eligible. Check each channel's own shipping rules before routing its orders.

How long does Walmart take to publish items added through the API?

Not instantly. Walmart describes two stages after you send an item: submission, where Walmart parses and classifies it, and publishing, once required attributes are confirmed. Its documentation says each stage typically takes a few hours. An integration should therefore check feed status and item status afterwards, report any errors back to you, and only push stock and prices once the item is live, rather than assuming a listing exists because it was sent.

To plan a Walmart integration, send me a short brief: where you sell today, which system holds your stock, whether you use FBA or WFS, roughly how many SKUs and orders you handle, and when you want Walmart live. You can ask for a quote on the Flexible marketplace plan, read more on the ecommerce automation page, or start with what to automate first in ecommerce.