E-commerce is constantly exploring opportunities to streamline payment service integration, particularly in terms of purchase channels and settlement methods. Traditionally, such integrations were provided through bank-acquirers. New initiatives such as Open Banking present a novel approach by offering a centralized gateway for third-party access to banking services. The purpose of this paper is to propose a sample model of a merchant gateway that leverages distributed ledger technology to enable seamless integrations with both purchase and settlement systems. The model holds the potential for accelerating purchase and withdrawal processing but also introduces new challenges that need to be addressed.