Devices whose SDK session carried this transaction externalId as its session id. The integration passes that same value to the SDK, so this is how an order number resolves to the devices behind it — in one call: each row is the device identity, its latest Smart Signals event (smartSignals) and the event of this very attempt (sessionSmartSignals, the one whose linkedId equals the externalId). Both snapshots carry the raw userAgent and its parse (osName, osVersion, browserName, browserMajorVersion, browserDevice). Raw sessions stay one call further, on get-sessions.