Walmart Multichannel Solutions: merchant plugin guide

About this guide

This guide describes ChannelEngine's merchant plugin for Walmart MCS (Multichannel Solutions).

Table of contents

Introduction

Requirements

Limitations

Supported features

Supported channels

How to request an account

Settings and configuration

• Merchant API setup
• Setup
• Activation
• Order routing

Additional information

FAQs

Introduction

Walmart MCS (Multichannel Solutions) is a solution that allows merchants to use Walmart Fulfillment Services (WFS) to fulfill orders placed on channels beyond Walmart.com. Use Walmart's fulfillment centers and carrier network across the United States and consolidate your fulfillment by routing orders from channels such as Amazon and Target Plus through WFS.

ChannelEngine offers a plugin to the Walmart MCS platform that enables you to automatically synchronize your WFS inventory levels with your connected marketplaces and route orders to Walmart MCS for fulfillment – without manual intervention in Walmart Seller Center.

Requirements

• Sell on Walmart Marketplace and be enrolled in WFS (Walmart Fulfillment Services). Products fulfilled by Walmart MCS must be stocked in WFS warehouses.
• Have a default billing method on file for WFS fees.
• If you already use an active Walmart seller account tied to WFS inventory, use those same credentials when authorizing the Walmart MCS plugin on ChannelEngine*.
• Enable the Advanced order management add-on in your tenant. Check out ChannelEngine: advanced order management [add-on]**.
• Via advanced order management, manage your own stock locations and the Walmart MCS stock locations on ChannelEngine.**
• Install and activate the Walmart MCS merchant plugin in your tenant.
• Accurately filter and acknowledge orders whose lines only you fulfill, via the Merchant API or, under the supervision of your ChannelEngine contact, via a separate merchant plugin.

*If you already authorized your Walmart channel using OAuth 2, then your Walmart MCS plugin is automatically configured to connect to Walmart's backend.

**If you only manage a single stock location – the Walmart MCS stock location – on ChannelEngine, then you do not require advanced order management.

Limitations

Geographical limitations

• Walmart MCS fulfills orders within the United States only, including all 50 states and Puerto Rico. It is not available for international shipping.
• Walmart MCS does not deliver to PO Boxes. Orders with a PO Box shipping address cannot be fulfilled.

Product-related limitations

• Multi-box and big and bulky items are not eligible for Walmart MCS. Items must meet WFS product requirements to participate in the program.
• Items weighing between 31 and 150 lbs are not eligible for expedited (2-business-day) shipping and are limited to standard shipping only.
• Merchants can enable Walmart MCS on products sold on non-Walmart channels only if those products are also listed and stocked in WFS on Walmart.com.

Implementation limitations

• Merchants should not acknowledge orders that contain order lines assigned to a Walmart MCS stock location. If you acknowledge such an order, Walmart MCS does not receive it and cannot fulfill it.
• If Walmart MCS cancels an order (e.g.: due to insufficient stock), ChannelEngine does not automatically reroute the order to another warehouse. Rerouting a canceled MCS order currently requires manual intervention or a custom flow built via the Merchant API. You are responsible for following up with orders that Walmart MCS cancels.
• The shipping template (Value, Standard, or Two-day) is configured by the merchant in the Walmart Multichannel portal, not on ChannelEngine. It cannot be adjusted per order on ChannelEngine.
• Shipping speeds are not guaranteed during peak periods (October 1-December 31), sales events, and other circumstances.

Supported features

Supported channels

Walmart MCS supports any sales channel, as long as your orders and returns comply with the terms of service of the originating channel, and the shipping speed and packaging Walmart uses are appropriate for that channel. You have complete flexibility over which channels are fulfilled – by default, items are listed on Walmart.com, but you can also sell exclusively on off-Walmart channels.

The table below is a representative list of channels for which ChannelEngine has confirmed compatibility with Walmart MCS order routing. Other channels can also be connected, provided they are first configured in Walmart Seller Center under Multichannel Settings.

How to request an account

To use Walmart MCS, you must first enroll in WFS (Walmart Fulfillment Services) and be approved for Multichannel Services. Contact your Walmart Marketplace account manager or apply directly through Walmart Seller Center to request access. Once approved, configure your eligible sales channels under Multichannel Settings in Walmart Seller Center before connecting to ChannelEngine.

Settings and configuration

Merchant API setup

Set up a workflow to ensure you do not accidentally acknowledge orders that contain lines that Walmart MCS must fulfill. The recommended setup is via the Merchant API.

Before setting up your Walmart MCS merchant plugin, first configure the /v2/orders/ endpoint between ChannelEngine and your order management system via the Merchant API.

1. Retrieve orders from ChannelEngine with statuses New and In progress.
2. Analyze New and In progress orders to check whether they are Walmart MCS-fulfilled or merchant-fulfilled.
3. Via the Merchant API, only acknowledge merchant-fulfilled orders whose order lines all belong to your own warehouses.
4. Fulfill your own order lines via the Merchant API.

Retrieve orders

To retrieve orders from channels where Walmart MCS also fulfills orders, use the GET /v2/orders endpoint with the following parameters:

Request parameters

Example query:

GET /v2/orders?statuses=NEW&statuses=IN_PROGRESS&stockLocationIds=YOUR_WAREHOUSE_ID&fulfillmentType=ONLY_MERCHANT&channelIds=X&fromUpdatedAtDate=2026-08-01%2000:00:00

Setup

In Walmart Seller Center

In Walmart Seller Center, generate the API credentials needed to connect to ChannelEngine and configure your sales channels for MCS:

1. Log in to Walmart Seller Center.
2. Navigate to Settings, API Access.
3. If you do not use OAuth 2.0 to connect to Walmart, generate your Client ID and Client Secret.
4. Navigate to WFS, Multichannel Settings and add each sales channel you intend to fulfill through MCS. Each channel configured here generates a token ID used to communicate inventory and order data between Walmart and that channel.

Save your credentials to complete the connection in the ChannelEngine plugin.

On ChannelEngine

Add the plugin

To add the Walmart MCS plugin to your tenant on ChannelEngine:

1. In the sidebar menu, go to Plugins.
2. Search for 'Walmart MCS' in the search bar.
3. The Walmart MCS plugin box appears.
4. On the box, click + Request to configure.

The ChannelEngine team presets your settings in Connection in close collaboration with you and your team.

Connection

If you do not connect to Walmart Seller Center via OAuth 2*, configure the following fields:

• Client ID – your Walmart API Client ID, generated in Walmart Seller Center. Not required if you use OAuth 2 to authorize your Walmart connection.
• Client Secret – your Walmart API Client Secret, generated in Walmart Seller Center. Not required if you use OAuth 2 to authorize your Walmart connection.

*If you already authorized your Walmart channel using OAuth 2, then your Walmart MCS plugin is automatically configured to connect to Walmart's backend; there are no settings for you to configure in Connection.

Plugin-specific settings

• Partner ID – (required) the partner ID associated with your Walmart account.
• Logged in user – (required) the email address associated with your Walmart account.
• Sales channel for [channel] – if you use Walmart MCS on channels that support multiple stock locations, such as Target Plus or TikTok Shop, select the name of the corresponding channel, e.g.: for Walmart MCS sales channel for Target, select Target. The dropdown options appear after you authorize the channel in Authorization and click Import sales channels in Actions.

Actions

Once you authorize the connection between ChannelEngine and the Walmart MCS portal, the Actions section appears. Click Import sales channels to retrieve the available sales channels from your Walmart Seller Center account. ChannelEngine imports Walmart MCS's WFS warehouses as Stock locations on ChannelEngine.

Activation

Continue with the activation in the Activation step.

Once the plugin is activated, ChannelEngine begins synchronizing inventory levels between the Walmart MCS stock locations and ChannelEngine.

Order routing

Create order routing rules between your connected channels and the Walmart MCS stock location. E.g.: for Target Plus orders, set up an order routing rule named 'Walmart MCS', linked to the Walmart MCS stock location.

To enable order routing on ChannelEngine:

1. Reach out to ChannelEngine's Support team to enable the advanced order management feature in your tenant. For details, check out ChannelEngine: advanced order management [add-on].
2. From the sidebar, click Orders, Routing. Then, click Add.
3. In the Add: Order routing dialog box, enter information in the following fields:
   • Name – the order routing's name, e.g.: 'Walmart MCS'.
   • Select channels – click the dropdown to select the channel that applies to this routing, e.g.: Target Plus. Note that you can only select a channel that is not already active in another routing.
   • Select stock locations – select the Walmart MCS stock location. Only select one location.
4. Click Add.

Order routing for channels that support multiple stock locations

If you use Walmart MCS to fulfill orders on channels that only support sending inventory from multiple stock locations, e.g.: Target Plus, make sure to configure your warehouses on the channel's backend first. Also make sure that the Walmart MCS stock location is set up on the channel's backend. Once that is done:

1. Import the channel's stock locations into ChannelEngine and complete the stock location mapping in the channel's Stock step.
2. Map your Merchant stock location to the corresponding Channel stock location. This mapping enables ChannelEngine to send stock levels from each of your stock locations directly to the channel. Thereafter, the channel runs its own algorithm to select the specific stock location for order processing; ChannelEngine's order routing rules do not override the channel's algorithm.

Additional information

Order acknowledgment

Do not acknowledge orders that contain lines that a Walmart WFS warehouse should fulfill. For guidance, check out Merchant API: order line fulfillment via multiple systems.

Shipments

When Walmart MCS confirms a fulfillment order from one of your connected channels, ChannelEngine automatically creates the shipment with the correct shipment method and tracking code. Walmart MCS only uses carriers included in a defined service package. E.g.: when using Package C, Walmart ships with FedEx, UPS, or USPS only.

For orders containing multiple units that ship in separate boxes, Walmart MCS may generate multiple tracking numbers for a single order. ChannelEngine monitors the total quantity ordered against the total quantity shipped and only marks an order as fully shipped when those values match. Secondary tracking numbers from subsequent shipments are imported automatically.

Cancelations

The plugin supports both Walmart MCS-initiated cancelations (e.g.: when stock is unavailable) and marketplace-initiated cancelations. When a buyer requests a cancelation, ChannelEngine submits the request to Walmart MCS. Cancelations succeed only if the order has not yet entered the fulfillment process – once an order is in progress, Walmart MCS is unlikely to be able to cancel it. ChannelEngine reflects Walmart's response (approved or declined) back to the originating channel.

Shipping templates

Walmart MCS ships orders using the fulfillment template configured for each sales channel in the Walmart Multichannel portal. This template is set by the merchant and cannot be adjusted per order via ChannelEngine. Fulfillment fees differ by template and item weight.

WFS inventory

ChannelEngine syncs WFS inventory levels from Walmart. For products that have MCS inventory, a dedicated stock location is displayed on the Product details page on ChannelEngine, showing the current WFS inventory available. Inventory values update automatically each time ChannelEngine synchronizes with Walmart MCS – this happens during every inventory, order, or shipment sync cycle.

Inventory buffer

Because there is a short delay between the moment stock is updated in Walmart's systems and when that update reaches ChannelEngine, it is possible for orders to arrive for items that are no longer available in WFS – causing Walmart MCS to cancel the order. To reduce this risk, configure a stock buffer of at least 5 units per item. This gives you a safety margin during delta timing windows and lowers your overall cancelation rate.

Stock buffers can be configured per channel on ChannelEngine under the channel's Stock settings. If you sell across multiple channels with different sales velocities, consider setting tighter buffers for slower-moving channels and higher buffers for faster-moving ones.

Returns

Walmart MCS manages returns centrally through its fulfillment network. When a customer initiates a return on a connected channel, ChannelEngine can submit a return request to Walmart MCS. Walmart handles the physical return logistics and provides status updates that ChannelEngine imports automatically.

Return rules – including whether returned items are restocked, disposed of, or shipped back to the merchant – are governed by the settings in your Walmart Seller Center account, not on ChannelEngine.

Using Walmart MCS alongside other fulfillment services

Walmart MCS can be used alongside other multi-channel fulfillment services, such as Amazon MCF (Multi-Channel Fulfillment). In this setup, ChannelEngine routes each order to the appropriate fulfillment provider based on your order routing rules. E.g.: you may route Amazon orders to Amazon MCF and Target Plus orders to Walmart MCS, with both plugins active in your tenant simultaneously.

To manage multiple fulfillment providers on ChannelEngine, configure a separate order routing rule for each provider, each mapped to its own stock location. Ensure that your stock buffers and location-level stock limitations are set correctly for each channel, so that inventory from each fulfillment provider is exported accurately.

FAQs

How often do tasks run on the Walmart MCS plugin?

The Walmart MCS plugin runs the following background tasks on a scheduled basis: