Relay
Relay API Reference
by Last Mile Solutions · v2.15
🔒 Confidential & Proprietary. Prepared for the authorized integration team. Contains confidential commercial and operational information of Last Mile Solutions — do not redistribute.

Relay — returns & shipping coordination

Relay is Last Mile Solutions' returns & shipping coordination network. Quote a return, ingest the order with its marketplace context, hand the customer a print-at-home label or a QR code, and follow the parcel through possession, sort, carrier injection, and delivery — over one unified, versioned API.

Returns are the primary flow. Service is configured per market. Money is integer cents; timestamps are ISO-8601 UTC; every POST accepts an Idempotency-Key.

Auth: X-Api-Key + HMAC signature IDs: shp_ pkp_ rate_ adj_ whk_ qr_ loc_ evt_ Release 2.15.0 Base path /v2
Relay API · Release 2.15.0 · Base path /v2 · © Last Mile Solutions. Confidential & Proprietary — for the intended recipient only; not for redistribution. This reference is self-contained and works offline.