From Findings to Reports: Multi-Agent Smart Contract Repair-as-a-Service with Tool Fusion, Deduplication, and Second-Pass Validation

Blockchain technology has emerged as a transformative force across industries, powering Decentralized Finance (DeFi) protocols, enabling Traditional Finance (TradFi) institutions to tokenize real-world assets, streamlining cross-border payments, and underpinning smart contract-based automation in healthcare, supply chains, and governance. However, smart contract security remains a critical challenge, and existing automated repair tools often struggle with high false-positive rates and fragmented reporting. In this paper, we introduce a Multi-Agent Smart Contract Repair-as-a-Service framework designed to streamline the transition from vulnerability findings to actionable reports. Our framework distinguishes itself through an integrated Tool Fusion engine that harmonizes various analysis techniques, a Deduplication layer to eliminate redundant findings, and an agent-based Second-Pass Validation mechanism to ensure the correctness and feasibility of generated patches. By leveraging a multi-agent architecture, our approach provides a comprehensive, end-to-end service that enhances the reliability and efficiency of smart contract maintenance. Experimental results indicate that our framework achieved an accuracy of 77.51% and a filtering rate of 22.49% across 498 detected bugs in the Web3Bugs dataset.