OneRail’s last-mile logistics operating system gives shippers access to a vast network of couriers, including Lyft’s, Uber’s and PostMates’ driver networks, integrating them directly into shippers’ transportation management systems, warehouse management systems, point-of-sale systems or e-commerce engines.

This is essentially a marketplace provider which allows you to manage a network of couriers. They don't provide their own gig workers, etc.

FreightWaves: OneRail raises $9M Series A to scale last-mile delivery network