Check the status and tracking of a physical letter previously sent via POST /api...

{ "body": {}, "bodyType": "json", "method": "POST", "type": "http" }

{ "errors": { "400": { "description": "Invalid or missing parameter(s). Returned before the payment gate on paid requests, so a malformed call is never charged. JSON body: { error: <what is wrong and how to fix it> } plus usage hints.", "example": { "error": "invalid request" } }, "402": { "description": "Payment required — x402 v2 challenge; the accepts array lists scheme, network, and amount. Retry the same request with a PAYMENT-SIGNATURE (v2) or X-PAYMENT (v1) header. Verification is free." }, "500": { "description": "Unexpected server error. If a payment settled without a usable result, contact info@theaslangroupllc.com with the settlement tx hash for a re-run or credit.", "example": { "error": "upstream_failed" } } }, "example": { "carrier": "USPS", "expected_delivery_date": "2026-07-23", "id": "ltr_...", "mode": "test", "status": "rendered", "tracking_number": null }, "type": "json" }