This API generates a scan form using the provided tracking numbers. The scan form is a consolidated document that contains all the tracking numbers and shipping details for the packages being shipped out on a particular day. It is used by carriers to verify and process the shipments during pickup and delivery. Currently, only USPS supports scan forms.

Idempotency: scanFormId acts as a natural idempotency key — the client supplies it in the request body before the call. Submitting a second POST with a scanFormId that was already successfully processed returns 409 Conflict; no duplicate scan form is created. On network failure or timeout, clients may safely retry using the same scanFormId. This guarantee is critical for EOD automation — a duplicate manifest can cause carrier processing errors and shipment delays.

Rate Limits: This endpoint allows 100 requests per minute. Exceeding this limit returns a 429 Too Many Requests response. See the Rate Limiting guide for full details. The response includes x-current-token-count (remaining requests in the current window) and X-Next-Replenishment-Time (when the token count next increases).

Sandbox: Use base URL https://sandbox.walmartapis.com. The sandbox accepts test tracking numbers and returns a synthetic manifestId (e.g. SANDBOX-12345). Use that manifestId with the GET endpoint to retrieve the stub scan form document.