Online Joint Fine-tuning of Multi-Agent Flows
Paul Mineiro
TL;DR
This work tackles online joint fine-tuning of multi-agent flows by leveraging an environment simulator to convert episode-level preferences into node-level preferences, enabling language-model components to be trained without granular supervision. It borrows Learning to Search principles and one-step deviation credit assignment to optimize greedy inference in complex, looped flows, and it uses an online DPO-style preference learner with Coin Betting optimization and LoRA adapters. The approach is demonstrated on Musique, achieving state-of-the-art results on both Musique-Answerable and Musique-Full, including reward-free and text-feedback scenarios. The discussion notes practical limitations, such as the need for simulator access and the sensitivity to initialization, and it outlines potential directions for broader evaluation and single-sample learning in production settings.
Abstract
A Flow is a collection of component models ("Agents") which constructs the solution to a complex problem via iterative communication. Flows have emerged as state of the art architectures for code generation, and are the raison d'etre for frameworks like Autogen. However, flows are currently constructed via a combination of manual prompt engineering and stagewise supervised learning techniques; the latter is limited to acyclic flows with granular node supervision. In this writeup I describe a procedure for online joint fine-tuning of an entire flow inspired by the Learning to Search framework. The approach leverages simulator access to reduce preferences over entire episodes to preferences over individual node outputs; when the components are language models the latter is a well-studied problem. The approach is applicable to reward-free settings (e.g., text feedback) if an episode evaluator model is available. I apply to the multi-hop QA dataset Musique achieving a state-of-the-art result.
