Xander Xu
Author directory2026
Beyond Quantity: Trajectory Diversity Scaling for Code Agents
Guhong Chen | Chenghao Sun | Cheng Fu | Qiyao Wang | Zhihong Huang | ChaoPeng Wei | Guangxu Chen | Feiteng Fang | Ahmadreza Argha | Bing Zhao | Xander Xu | Qi Han | Hamid Alinejad-Rokny | Qiang Qu | Binhua Li | Shiwen Ni | Min Yang | HU Wei | Yongbin Li
Findings of the Association for Computational Linguistics: ACL 2026
Guhong Chen | Chenghao Sun | Cheng Fu | Qiyao Wang | Zhihong Huang | ChaoPeng Wei | Guangxu Chen | Feiteng Fang | Ahmadreza Argha | Bing Zhao | Xander Xu | Qi Han | Hamid Alinejad-Rokny | Qiang Qu | Binhua Li | Shiwen Ni | Min Yang | HU Wei | Yongbin Li
Findings of the Association for Computational Linguistics: ACL 2026
As code large language models (LLMs) evolve into tool-interactive agents via the Model Context Protocol (MCP), their generalization is increasingly limited by low-quality synthetic data and the diminishing returns of quantity scaling; moreover, quantity-centric scaling exhibits an early bottleneck that underutilizes trajectory data. We propose TDScaling, a Trajectory Diversity Scaling-based data synthesis framework for code agents that scales performance through diversity rather than raw volume. Moreover, TDScaling is more data-efficient: under a fixed training budget, increasing trajectory diversity yields larger gains than adding more trajectories, improving the performance-cost trade-off for agent training. TDScaling integrates four innovations: (1) a Business Cluster mechanism that captures real-service logical dependencies; (2) a Blueprint-driven multi-agent paradigm that enforces trajectory coherence; (3) an adaptive evolution mechanism that steers synthesis toward long-tail scenarios using Domain Entropy, Reasoning Mode Entropy, and Cumulative Action Complexity to prevent mode collapse; and (4) a sandboxed code tool that mitigates catastrophic forgetting of intrinsic coding capabilities. Experiments on general tool-use benchmarks (BFCL, 𝜏2-Bench) and code agent tasks (RebenchT, CodeCI, BIRD) demonstrate a win-win outcome: TDScaling improves both tool-use generalization and inherent coding proficiency. Crucially, we show that trajectory diversity scaling attains a substantially higher performance ceiling than quantity scaling, establishing a resource-efficient paradigm for training robust code agents under data bottlenecks.
V-GameGym: Visual Game Generation for Code Large Language Models
Wei Zhang | Jian Yang | Renshuai Tao | Linzheng Chai | Shuyue Guo | Jiajun Wu | Xiaoming Chen | Ganqu Cui | Ning Ding | Xander Xu | HU Wei | Bowen Zhou
Findings of the Association for Computational Linguistics: ACL 2026
Wei Zhang | Jian Yang | Renshuai Tao | Linzheng Chai | Shuyue Guo | Jiajun Wu | Xiaoming Chen | Ganqu Cui | Ning Ding | Xander Xu | HU Wei | Bowen Zhou
Findings of the Association for Computational Linguistics: ACL 2026
Code large language models have demonstrated remarkable capabilities in programming tasks, yet current benchmarks primarily focus on single modality rather than visual game development. Most existing code-related benchmarks evaluate syntax correctness and execution accuracy, overlooking critical game-specific metrics such as playability, visual aesthetics, and user engagement that are essential for real-world deployment. To address the gap between current LLM capabilities in algorithmic problem-solving and competitive programming versus the comprehensive requirements of practical game development, we present V-GameGym, a comprehensive benchmark comprising 2,219 high-quality samples across 100 thematic clusters derived from real-world repositories, adopting a novel clustering-based curation methodology to ensure both diversity and structural completeness. Further, we introduce a multimodal evaluation framework with an automated LLM-driven pipeline for visual code synthesis using complete UI sandbox environments. Our extensive analysis reveals that V-GameGym effectively bridges the gap between code generation accuracy and practical game development workflows, providing quantifiable quality metrics for visual programming and interactive element generation.
Streaming Communication in Multi-Agent Reasoning
Zhen Yang | Xiaogang Xu | Wen Wang | Cong Chen | Xander Xu | Ying-Cong Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Zhen Yang | Xiaogang Xu | Wen Wang | Cong Chen | Xander Xu | Ying-Cong Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Multi-agent reasoning systems adopt a generate-then-transfer paradigm that forces end-to-end latency to scale linearly with pipeline depth. We introduce StreamMA, a multi-agent reasoning system that streams each reasoning step to downstream agents as soon as it is generated, pipelining adjacent agents and thus reducing latency. Surprisingly, this pipelining also improves effectiveness: because multi-step reasoning quality is non-uniform and early steps are more reliable than later ones, working with these reliable early steps instead of the full chain prevents error-prone late steps from misleading downstream agents. We formalize both advantages with the first closed-form joint analysis of stream, serial, and single protocols, deriving the effectiveness ordering, speedup upper bound, and cost ratio. Across eight reasoning benchmarks spanning mathematics, science, and code, three frontier LLMs (Claude Opus 4.6, GPT-5.4, and GLM-5.2), and three topologies (Chain, Tree, Graph), StreamMA outperforms both baselines (avg.+7.3pp, max +22.4pp on HMMT2026; Claude Opus 4.6-High). Beyond these contributions, we discover a step-level scaling law: increasing per-agent steps consistently improves both effectiveness and efficiency, a new scaling dimension orthogonal to and composable with agent-count scaling.
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Co-authors
- HU Wei 2
- Hamid Alinejad-Rokny 1
- Ahmadreza Argha 1
- Linzheng Chai 1
- Cong Chen (陈聪) 1
- Guangxu Chen 1
- Guhong Chen 1
- Xiaoming Chen 1
- Ying-Cong Chen 1
- Ganqu Cui 1
- Ning Ding 1
- Feiteng Fang 1
- Cheng Fu 1
- Shuyue Guo 1
- Qi Han 1
- Zhihong Huang 1
- Binhua Li 1
- Yongbin Li 1
- Shiwen Ni 1
- Qiang Qu 1
- Chenghao Sun 1
- Renshuai Tao 1
- Qiyao Wang 1
- Wen Wang 1
- ChaoPeng Wei 1
- Jiajun Wu 1
- Xiaogang Xu 1
- Jian Yang 1
- Min Yang 1
- Zhen Yang 1
- Wei Zhang 1
- Bing Zhao 1
- Bowen Zhou 1