ToolVerse: Unlocking Massive Environments and Long-Horizon Tasks for Agentic Reinforcement Learning Researchers introduce ToolVerse, a framework that scales up agentic reinforcement learning environments using nearly 400 real-world Model Context Protocols containing about 4,500 tools, enabling LLM agents to perform complex long-horizon reasoning in tool-integrated tasks. The framework includes a Dynamic Unlocking Sampling Algorithm to generate long-horizon tasks and a Turn-Aware Relative Advantage algorithm to address credit assignment, achieving significant performance boosts on agentic benchmarks. arXiv:2607.15660v1 Announce Type: new Abstract: While LLM agents demonstrate strong reasoning abilities in compact and well-defined scenarios, they struggle to maintain robustness and effectiveness when faced with large-scale, diverse, and dynamic real-world environments that demand seamless tool integration. To address this gap, we introduce ToolVerse, a comprehensive framework that scales up agentic RL environments and enables agents to perform complex long-horizon reasoning in Tool-Integrated Reasoning TIR tasks. First, ToolVerse automatically builds the massive executable agent training environments from nearly 400 real-world Model Context Protocols MCPs that contain about 4500 tools. Second, we propose a task design strategy based on a tool dependency graph, utilizing Dynamic Unlocking Sampling Algorithm to generate long-horizon tasks, and produce GUST Graph Unlocking Sampling Tasks dataset. Third, to alleviate the credit assigment problem in long-horizon agentic RL, we propose a fine-grained Turn-Aware Relative Advantage algorithm. We conduct extensive Agentic RL training using ToolVerse and evaluate our framework on serveral agentic benchmarks. Experimental results demonstrate that our framework significantly strengthens LLMs' capabilities in long-horizon tool use, achieving a marked performance boost and showcasing robust reasoning within dynamic environments.