Rate-shop a vendor RTV shipping label (estimate, no buy)
Live rate-shop for a vendor return-to-vendor (RTV) shipping label using the entity’s configured Shippo carrier accounts. Returns the available rates[] WITHOUT purchasing a label (estimate only). Ship-from is the default warehouse; ship-to is the vendor’s configured RMA return address (422 vendor_rma_address_not_configured when the vendor has no RMA or default address). Mirrors the customer return-label rate-shop contract.
Authorization: compound read scope, requires BOTH returns:read AND fulfillment:read.
Authorizations
API key issued per entity via Settings > Developers > API Keys.
Each key carries scopes (e.g. orders:read, products:write).
Bearer token format: Authorization: Bearer ark_live_ent_
Test keys use ark_test_ent_. Both are issued per entity
via Settings > Developers > API Keys.
Path Parameters
Query Parameters
Parcel length in inches (default 12).
Parcel width in inches (default 10).
Parcel height in inches (default 6).
Parcel weight in pounds (default 2).
Response
Available vendor RTV label rates (estimate)

