Clearer

The Clearer component supports the Router component in managing the obligations of different PSPs and PSUs in the role of Tapestry as a CSM. The Clearer provides real-time clearing against settlements accounts maintained for PSPs and PSUs in the Ledger component. Settlements are effected through the Settler component by the Router.

The Clearer does not do netting and the clearing and settling paradigm is closer to an RTGS than a DTNS. As the clearing and settling paradigm is that of an RTGS, the Clearer does clearing on individual payment transactions, one at a time. In a DTNS payment system, the clearing step has some algorithmic complexity in calculating the multilateral net positions between participating PSPs.

In an RTGS, it is sufficient only to ascertain that the sending PSP has sufficient balance. As Tapestry implements an RTGS paradigm most of the work of clearing and settlement is done by the Router and Settler. The role of the Clearer is limited to looking up the sending and receiving PSPs using the routing tables populated by the Router.