This paper presents an abstract metamodel designed for the development and implementation of smart contracts (SCs). Since the launch of Ethereum, smart contracts have gained considerable attention as a tool for encoding and regulating exchanges between multiple parties. The rise in their use has led to the creation of numerous SC programming languages, each with its own unique syntax and structure. However, these languages are typically tailored to specific blockchain platforms, creating challenges when migrating to different platforms that require different languages. To address this issue, we propose a standardized approach to smart contract development through the introduction of an abstract metamodel. This metamodel, grounded in model-driven engineering principles, generates a platform-independent SC model by integrating the essential components and rules of various SC languages. By offering a unified abstraction, the metamodel aims to simplify the development process, allowing developers to work across multiple blockchain platforms without needing to learn new languages for each one. The effectiveness of this approach is demonstrated through its application to smart contracts written in different SC languages. Additionally, the proposed metamodel holds promise for future applications in model transformation and automated code generation, enhancing cross-platform compatibility and reducing platform dependency.