Relay API
by Last Mile Solutions · returns & shipping coordination
Sandbox · operationalProduction · not yet approved
This is the Relay sandbox environment — every endpoint is live and returns realistic test-mode data. Point your integration here to build and test against the full API surface before production.
Base URL
https://sandbox.relay.lastmile.us/v2
Release
2.15.0 · mode: test
Authenticate with
🔒 Confidential & Proprietary. For the authorized integration team only — do not redistribute.
X-Api-Key + HMAC signature (see the authentication guide). Legacy /v1 requests auto-advance to /v2.🔒 Confidential & Proprietary. For the authorized integration team only — do not redistribute.