Overview

In mid‑March 2023, Amazon rolled out a critical update to the SP‑API’s Fulfillment by Amazon (FBA) Inventory API. The change introduces a 30‑second expiration for the nextToken used in pagination, eliminating the blank‑response errors that previously plagued inventory retrieval scripts. Sellers who rely on automated inventory feeds must adjust their integrations right away to keep data accurate and avoid unnecessary API calls.

Key Points

• 30‑Second nextToken lifespan — Tokens now expire 30 seconds after issuance, forcing developers to paginate quickly.
• Blank‑response error eliminated — The update stops empty responses that were triggered by expired or misused nextToken values.
• startDateTime now works with pagination — The API correctly handles startDateTime parameters alongside nextToken, ensuring accurate inventory snapshots.
• Legacy calls remain functional — Existing API requests that omit nextToken continue to work unchanged, preserving backward compatibility.
• Clear error messages for expired tokens — Requests with an expired token now return a specific “TokenExpired” error instead of a silent failure.
• Security and performance gains — Shorter token validity reduces the risk of replay attacks and cuts down on redundant pagination attempts.

How the Updated API Works

1. Initial inventory request — Call GetInventorySupply with an optional startDateTime.
   • Example: GET /fba/inventory/v1/supplies?startDateTime=2023-03-01T00:00:00Z.
2. Receive first page — The response includes inventory items and a nextToken if more data exists.
   • Example: nextToken: "abc123".
3. — Store the token and note the exact time it was received; plan to use it within 30 seconds.