Overview

Amazon has introduced two new dynamic sandbox environments for the Fulfillment By Amazon (FBA) Inventory API and the FBA Outbound API. The sandboxes allow developers to execute full‑cycle tests—receiving shipments, adjusting stock, and fulfilling orders—without affecting any real seller account. This capability gives sellers and solution providers a safe space to verify code, troubleshoot edge cases, and certify integrations before they go live, thereby lowering the chance of costly mistakes.

Key Points

• Separate sandbox instances — One sandbox is dedicated to inventory‑related calls and another to outbound fulfillment, each reproducing the behavior of its production counterpart.
• Live‑like response timing — The test environments return status codes, latency, and payload structures that match the live APIs, so developers see realistic feedback.
• Persistent state across calls — Actions such as posting a shipment receipt, updating a SKU quantity, or creating a removal order remain stored for the duration of the session, enabling multi‑step scenarios in a single run.
• Isolation from real listings — All operations are confined to the sandbox, guaranteeing that test activity cannot alter a seller’s actual inventory, buy‑box eligibility, or sales statistics.
• Error‑injection capability — By setting a special header, developers can force common failure responses—like “InsufficientInventory” or “InvalidSKU”—to validate error‑handling logic.
• No charge for access — The sandboxes are freely available to any developer with an Amazon Marketplace developer account.

How the Dynamic Sandbox Works

1. Create a sandbox session — Call the createSandbox endpoint with the desired region and API type; the service returns a unique sandbox identifier.

   • Example: A logistics partner posts { "region": "NA", "type": "FBA_INVENTORY" } and receives sandboxId: "sbx-98765". All subsequent requests must include this ID in the header.