Hetero-Designer: Automated Design of Multi-Agent Systems with Heterogeneous LLMs

LLM-based Multi-agent systems (MAS) have shown strong capabilities across a wide range of domains. Their success largely hinges on the collaboration topology design, which has emerged as a central research focus in the automated MAS design. However, existing approaches are fundamentally constrained by their reliance on homogeneous LLMs, which significantly limits overall system intelligence. In response to this limitation, we for the first time propose the concept of Automated Design of Heterogeneous-LLMs-based MAS (ADHM). ADHM sheds light on a promising avenue for advancing collective intelligence, which focuses on the automated design of costeffective MAS composed of diverse LLMs and roles to suit various queries. Toward this challenging goal, we propose Hetero-Designer, a novel pipeline that efficiently encodes intricate dependencies among queries, LLMs and roles through a novel Binary-Star Transformer and constructs Hetero-MAS in an autoregressive graph generation process. Extensive experiments demonstrate that Hetero-Designer is: (i) high-performing on various benchmarks, (ii) economical in reducing overhead, (iii) extensible to unseen LLMs and roles.