AutoGraph-R1: End-to-End Reinforcement Learning for Knowledge Graph Construction

arXiv cs.AI / 4/23/2026

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Key Points

  • AutoGraph-R1 is introduced as a framework that directly optimizes knowledge graph (KG) construction for downstream task performance in RAG-based question answering, rather than treating KG building as a separate, generic step.
  • It uses reinforcement learning to train an LLM “constructor,” formulating graph generation as policy learning where rewards reflect the functional utility of the produced graph within a RAG pipeline.
  • The paper proposes two task-aware reward functions—one for treating graphs as knowledge carriers and another for treating graphs as knowledge indices—so the optimization aligns with how the KG is used.
  • Experiments on multiple QA benchmarks show AutoGraph-R1 enables graph-based RAG methods to outperform approaches that rely on task-agnostic baseline graphs.
  • Overall, the work demonstrates a “closed-loop” paradigm where KG construction is evaluated through application effectiveness, shifting focus from intrinsically “good” graphs to demonstrably “useful” graphs.

Abstract

Building effective knowledge graphs (KGs) for Retrieval-Augmented Generation (RAG) is pivotal for advancing question answering (QA) systems. However, its effectiveness is hindered by a fundamental disconnect: the knowledge graph (KG) construction process is decoupled from its downstream application, yielding suboptimal graph structures. To bridge this gap, we introduce AutoGraph-R1, the first framework to directly optimize KG construction for task performance using Reinforcement Learning (RL). AutoGraph-R1 trains an LLM constructor by framing graph generation as a policy learning problem, where the reward is derived from the graph's functional utility in a RAG pipeline. We design two novel, task-aware reward functions, one for graphs as knowledge carriers and another as knowledge indices. Across multiple QA benchmarks, AutoGraph-R1 consistently enables graph RAG methods to achieve significant performance gains over using task-agnostic baseline graphs. Our work shows it is possible to close the loop between construction and application, shifting the paradigm from building intrinsically ``good'' graphs to building demonstrably ``useful'' ones.