Multi-agent systems offer the advantage of performing tasks in a distributed and decentralized manner, thereby increasing efficiency and effectiveness. However, building these systems also presents challenges in terms of communication, security, and data integrity. Blockchain technology has the potential to address these challenges and to revolutionize the way that data is stored and shared, by providing a tamper-evident log of events in event-driven distributed multi-agent systems. In this paper, we propose a blockchain-based approach for event-sourcing in such systems, which allows for the reliable and transparent recording of events and state changes. Our approach leverages the decentralized nature of blockchains to provide a tamperresistant event log, enabling agents to verify the integrity of the data they rely on.