Hugging Face Daily Papers · · 4 min read

AREX: Towards a Recursively Self-Improving Agent for Deep Research

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\n<li>The model weights have been publicly released at: <a href=\"https://huggingface.co/collections/BAAI/arex\">https://huggingface.co/collections/BAAI/arex</a></li>\n<li>The models have also been integrated into our online application: <a href=\"https://arex-research.com/\" rel=\"nofollow\">https://arex-research.com/</a></li>\n</ul>\n","updatedAt":"2026-07-24T02:58:54.364Z","author":{"_id":"64a38c590111d5ff6c3d5f2b","avatarUrl":"/avatars/ef13dc7ce243819bc0da9b04e778b432.svg","fullname":"zhengliu","name":"lz1001","type":"user","isPro":false,"isHf":false,"isHfAdmin":false,"isMod":false,"followerCount":15,"isUserFollowing":false}},"numEdits":0,"identifiedLanguage":{"language":"en","probability":0.9362091422080994},"editors":["lz1001"],"editorAvatarUrls":["/avatars/ef13dc7ce243819bc0da9b04e778b432.svg"],"reactions":[{"reaction":"👍","users":["AlphaBIO","lsj2408"],"count":2}],"isReport":false}}],"primaryEmailConfirmed":false,"paper":{"id":"2607.21461","authors":[{"_id":"6a62d3662ee212ed0e2a148f","name":"Shuqi Lu","hidden":false},{"_id":"6a62d3662ee212ed0e2a1490","user":{"_id":"65ccbcfde75fc480714d1d04","avatarUrl":"/avatars/2def06230512892928537cf2d8499563.svg","isPro":false,"fullname":"Chaofan Li","user":"cfli","type":"user","name":"cfli"},"name":"Chaofan Li","status":"claimed_verified","statusLastChangedAt":"2026-07-24T16:45:04.139Z","hidden":false},{"_id":"6a62d3662ee212ed0e2a1491","user":{"_id":"627933c317c069c72a136b35","avatarUrl":"/avatars/f7aef400e47ac84897e6298c7c881c7a.svg","isPro":false,"fullname":"Kun Luo","user":"Lk123","type":"user","name":"Lk123"},"name":"Kun Luo","status":"claimed_verified","statusLastChangedAt":"2026-07-24T08:45:04.312Z","hidden":false},{"_id":"6a62d3662ee212ed0e2a1492","name":"Zhang Zhang","hidden":false},{"_id":"6a62d3662ee212ed0e2a1493","name":"Hui Wang","hidden":false},{"_id":"6a62d3662ee212ed0e2a1494","name":"Hongwang Xiao","hidden":false},{"_id":"6a62d3662ee212ed0e2a1495","name":"Zheng Liu","hidden":false},{"_id":"6a62d3662ee212ed0e2a1496","name":"Lei Xiong","hidden":false},{"_id":"6a62d3662ee212ed0e2a1497","name":"Jiahao Wang","hidden":false},{"_id":"6a62d3662ee212ed0e2a1498","name":"Sen Wang","hidden":false},{"_id":"6a62d3662ee212ed0e2a1499","name":"Xiyan Jiang","hidden":false},{"_id":"6a62d3662ee212ed0e2a149a","user":{"_id":"6777886b8c91ac2d4b705eaf","avatarUrl":"/avatars/ac27c6728d40edd724ce99cb8369808d.svg","isPro":false,"fullname":"Wanli Li","user":"wanlilll","type":"user","name":"wanlilll"},"name":"Wanli Li","status":"claimed_verified","statusLastChangedAt":"2026-07-24T08:45:04.307Z","hidden":false},{"_id":"6a62d3662ee212ed0e2a149b","name":"Yuyang Hu","hidden":false},{"_id":"6a62d3662ee212ed0e2a149c","name":"Hongjin Qian","hidden":false},{"_id":"6a62d3662ee212ed0e2a149d","name":"Bingyu Yan","hidden":false},{"_id":"6a62d3662ee212ed0e2a149e","name":"Ziyi Xia","hidden":false},{"_id":"6a62d3662ee212ed0e2a149f","name":"Yingxia Shao","hidden":false},{"_id":"6a62d3662ee212ed0e2a14a0","name":"Kang Liu","hidden":false},{"_id":"6a62d3662ee212ed0e2a14a1","name":"Zhicheng Dou","hidden":false},{"_id":"6a62d3662ee212ed0e2a14a2","name":"Di He","hidden":false},{"_id":"6a62d3662ee212ed0e2a14a3","name":"Chaozhuo Li","hidden":false},{"_id":"6a62d3662ee212ed0e2a14a4","name":"Qiwei Ye","hidden":false},{"_id":"6a62d3662ee212ed0e2a14a5","name":"Zhongyuan Wang","hidden":false},{"_id":"6a62d3662ee212ed0e2a14a6","name":"Zheng Liu","hidden":false}],"publishedAt":"2026-07-23T00:00:00.000Z","submittedOnDailyAt":"2026-07-24T00:00:00.000Z","title":"AREX: Towards a Recursively Self-Improving Agent for Deep Research","submittedOnDailyBy":{"_id":"64a38c590111d5ff6c3d5f2b","avatarUrl":"/avatars/ef13dc7ce243819bc0da9b04e778b432.svg","isPro":false,"fullname":"zhengliu","user":"lz1001","type":"user","name":"lz1001"},"summary":"Deep research requires agents to find answers that jointly satisfy multiple constraints. 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Papers
arxiv:2607.21461

AREX: Towards a Recursively Self-Improving Agent for Deep Research

Published on Jul 23
· Submitted by
zhengliu
on Jul 24
#1 Paper of the day
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Abstract

Deep research requires agents to find answers that jointly satisfy multiple constraints. Discovering such answers is costly, whereas verifying a candidate can often be decomposed into tractable constraint-wise checks. This discovery--verification asymmetry suggests that a research agent should do more than simply search longer: it should recursively improve its current answer by verifying intermediate results and using the partially verified state to guide subsequent refinement. We introduce AREX, a family of Recursively Self-Improving (RSI) deep research agents. AREX alternates between an inner research loop that gathers evidence and constructs a provisional answer, and an outer self-improvement loop that audits the answer constraint-wise, identifies unresolved claims, and launches targeted follow-up research. To sustain RSI over long horizons, AREX learns an autonomous context-update tool that compresses growing interaction history into a compact improvement state preserving verified evidence and unresolved constraints, without relying on an external model. We train AREX on verified synthetic tasks and high-quality trajectories through agentic mid-training and long-horizon reinforcement learning. To mitigate sparse final rewards during long horizon learning, we emphasize key steps where decisive evidence is acquired or erroneous research directions are corrected. We instantiate a dense 4B model and a 122B-A10B Mixture-of-Experts model. Across BrowseComp, WideSearch, DeepSearchQA, Humanity's Last Exam (HLE), and other reasoning and tool-use benchmarks, AREX substantially outperforms comparable-scale baselines and remains competitive with models using substantially more activated parameters.

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