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New: Dynamic sandbox and Simulations API

Date: Feb 18, 2026

Walmart Marketplace now offers a dynamic sandbox experience powered by Simulations APIs so partners can create custom test data and run more realistic, end-to-end test flows before going live. This expands sandbox testing beyond static mock datasets by letting responses reflect your inputs. (developer.walmart.com)

What changed

  • Added

    • Access to the dynamic sandbox via the sandbox base URL plus request header WM_SANDBOX: v2. (developer.walmart.com)
    • Simulations APIs (/v1/simulations/*) to create and manage test items and orders, including:
      • Items: POST /v1/simulations/items, PUT /v1/simulations/items/{sku}, GET /v1/simulations/items, GET /v1/simulations/items/{sku} (developer.walmart.com)
      • Orders: POST /v1/simulations/orders plus standard order lifecycle actions (get, acknowledge, cancel, ship) and simulated delivery POST /v1/simulations/{purchaseOrderId}/deliver. (developer.walmart.com)
    • Documented limits and behaviors for dynamic data (e.g., data deletion cadence and creation caps) and rate limits for supported endpoints. (developer.walmart.com)

  • Updated

    • Sandbox guidance to clarify that only a subset of Marketplace APIs support dynamic sandbox custom data; other APIs continue using static mock datasets. (developer.walmart.com)

  • Impacted areas

    • Sandbox testing workflows (switching between static vs dynamic behavior)
    • API requests (adding WM_SANDBOX: v2 for dynamic sandbox)
    • Item and order testing using v1/simulations/* endpoints and supported order lifecycle calls (developer.walmart.com)

Why it matters

  • Enables true end-to-end testing (create items → create orders → fulfill → deliver) in sandbox with partner-controlled scenarios. (developer.walmart.com)
  • Improves integration quality by letting you validate how your system handles variable, input-driven responses, not just static datasets. (developer.walmart.com)
  • Reduces friction for testing edge cases because simulated orders don’t require real-world constraints like valid payment methods, addresses, or tracking numbers. (developer.walmart.com)

Next steps