My Account

New: Sandbox Returns and Refunds, Inventory, and Settings Simulations

Date: May 07, 2026

Walmart Marketplace now supports additional dynamic sandbox capabilities for Returns and Refund simulations, Inventory, and Settings APIs. Partners can now create and manage custom return, refund, inventory, and fulfillment center test data to support more realistic end-to-end testing workflows before going live.

What changed

  • Added
    • Support for dynamic sandbox Returns and Refund simulation workflows using:
      • GET Returns - /v3/returns
      • POST Issue Refund - /v3/returns/{returnOrderId]/refund
      • POST Initiate Refund - /v1/simulations/returns
      • PUT Update Return - /v1/simulations/returns
    • Support for custom inventory test data (such as inventory reservations, decrements, and stockout scenarios) in the dynamic sandbox using Inventory APIs, including:
      • GET Inventory - /v3/inventory
      • PUT Update Inventory - /v3/inventory
      • GET Single Item Inventory per Ship Node - /v3/inventories/{sku}
      • PUT Update Item Inventory per Ship Node - /v3/inventories/{sku}
      • GET Multiple Item Inventory for All Ship Nodes - /v3/inventories
    • Support for fulfillment center (ship node) management in the dynamic sandbox using Settings APIs, including:
      • GET All Fulfillment Centers - /v3/settings/shipping/shipnodes
      • PUT Update Fulfillment Center - /v3/settings/shipping/shipnodes
      • POST Create Fulfillment Center - /v3/settings/shipping/shipnodes
  • Updated
    • Dynamic sandbox documentation to clarify that supported Returns and Refund simulation, Inventory, and Settings APIs now return customizable partner-defined test data.
    • Sandbox guidance to clarify that unsupported Marketplace APIs continue using static mock datasets.
  • Impacted areas
    • Inventory testing workflows using dynamic sandbox inventory data
    • Fulfillment center configuration using Settings APIs
    • Sandbox API requests using the WM_SANDBOX: v2 request header

Why it matters

  • Enables more realistic inventory and fulfillment testing using customizable sandbox data.
  • Improves validation for inventory availability, ship node configuration, and stockout scenarios before production onboarding.
  • Enables more realistic returns and refund testing using customizable sandbox data and simulated workflows.
  • Allows partners to validate return processing, refund handling, and downstream integration behavior before production onboarding.
  • Supports more complete end-to-end testing workflows by combining fulfillment center setup, inventory management, order simulation, fulfillment, delivery, returns, and refunds in a single sandbox environment.
  • Reduces dependency on static mock datasets by allowing responses to reflect partner-provided test inputs.
  • Simplifies edge-case testing because simulated returns and refunds do not require valid tracking numbers or payment methods.

Next steps

  • Use Returns simulation APIs to initiate and update sandbox return scenarios:

    • GET Returns - /v3/returns

    • POST Issue Refund - /v3/returns/{returnOrderId]/refund

    • POST Initiate Refund - /v1/simulations/returns

    • PUT Update Return - /v1/simulations/returns

  • Route calls to https://sandbox.walmartapis.com and include WM_SANDBOX: v2 to use the dynamic sandbox. (developer.walmart.com)

  • Use supported Inventory APIs to create and manage custom inventory test data.

  • Use supported Settings APIs to create and manage fulfillment centers (ship nodes).

  • Plan testing around dynamic sandbox constraints:

    • Data is purged periodically (every 2 days) and creation limits apply (e.g., capped test items/orders). (developer.walmart.com)

  • Refer to the updated documentation: