A Blockchain is a distributed ledger composed of a network of computers that facilitates the storage and retrieval of data and keeps a record in the form of transactions. Blockchains solve double spending problems and eliminate the need for a trusted third party. Along with providing a transaction processing platform, modern programmable blockchain platforms also provide an execution environment to establish business processes through custom logic in the form of smart contracts. Recent trends show growing interest in blockchain-based applications powered by smart contracts. With a growing number of smart contract enabled blockchain platforms, executing a business process that involves interacting with multiple heterogeneous blockchains has become an intricate task. A previous work proposed the Smart Contract Invocation Protocol (SCIP), a specification that defines a homogeneous interface that encapsulates the blockchain specific interaction details to invoke a smart contract feature. An initial implementation of SCIP, referred to as SCIP Gateway, enabled interaction with Ethereum, Hyperledger Fabric, and Bitcoin. For each type of supported blockchain, the SCIP gateway has an adapter. Since the initial SCIP gateway implementation in 2019, many new smart contract enabled blockchains have been launched. This thesis proposes analysis of state of the art smart contract enabled blockchain platforms and, based on the analysis, proposes adding four new methods to SCIP and updates to the methods proposed in the previous work. Along with three new adapters for the selected blockchain platforms, as a part of the work, this thesis proposes changes in existing adapters as well. Most importantly, SCIP and SCIP gateway can now allow communication between the client application for a collaborative execution of smart contract invocation(s). Another key feature that allows developers to create new adapters in a programming language-agnostic way has been proposed in this work. Furthermore, a testing framework for executing integration tests has been developed to validate the changes for the new adapters.