harness evolution
When you give an AI agent a complex job, you first build its "harness", the prompts, tools, and rules it follows. Evolution means automatically tweaking that harness, trying different versions, and keeping the ones that work better, all while leaving the AI's internal model unchanged.
Across the papers, the common thread is making harness evolution more efficient and reliable. They tackle two big problems: wasting evaluation effort on easy tasks, and overfitting to specific mistakes. Some methods sample tasks smartly to cut costs by up to 80%, others focus on failure patterns that repeat across many tasks, and some adapt the harness itself as the AI learns. The result is that evolved harnesses get better scores, transfer well to new tasks or different AI models, and require less manual engineering, turning harness tuning from a one-time human job into a continuous, automated process.
- Papers
- 66
- Released code
- 5
- First seen
- June 2026
- Latest
- Nov 2026
52 papers in the last two months, against 10 in the two before.
Start here
Three papers to read first, in the order they came out- 1Models can build their own agent software, but improvements generalize unreliably
LLMs can build capable task harnesses, but two rounds of self-revision do not reliably improve held-out performance and may trade performance for lower inference cost.
Oct 2026 - 2Robot agents approach teacher performance using one fifth the accelerator time
Harness evolution for a large teacher can be distilled into a compact student that achieves comparable success at one-fifth the compute.
Nov 2026 - 3AI agents complete roughly four times as many tasks with helpers
Reusable primitives with embedded LLMs, composed per task by HEELO, solve real-world tasks that frontier models fail to complete.
Nov 2026
How fast it is moving
Often studied with
agent harnessA system that structures, verifies, monitors, or controls how an AI agent interacts with external tools, environments, or execution runs.31 togetherself-evolving agentAn agent that improves by reusing its own experience, memory, or self-generated feedback, with success depending on verification and design.18 togetherfailure attributionIdentifying which component or step in a system caused an observed failure, often using structured trace representations.17 togetherWho is working on it
The papers
Most central to this idea first, not most recent.
- Academiccs.CL
AI agents complete roughly four times as many tasks with helpers
Reusable primitives with embedded LLMs, composed per task by HEELO, solve real-world tasks that frontier models fail to complete.
University of Illinois Urbana-Champaign, Georgia Institute of Technology · Nov 2026
- Chinese Techcs.CL
Reusable parts let a single fix repair many broken AI training environments
Building agent training environments from reusable, evolvable pieces, then repairing the pieces when an environment breaks, raises how many work and improves agent training.
Shanghai Jiao Tong University, Tencent · Nov 2026
- Chinese Techcs.RO
Robot agents approach teacher performance using one fifth the accelerator time
Harness evolution for a large teacher can be distilled into a compact student that achieves comparable success at one-fifth the compute.
Huawei Technologies Co., Ltd, Huawei Noah Research Institute · Nov 2026
- Big Techcs.AI
Models can build their own agent software, but improvements generalize unreliably
LLMs can build capable task harnesses, but two rounds of self-revision do not reliably improve held-out performance and may trade performance for lower inference cost.
Amazon, Technische Universität Dresden · Oct 2026
- Big Techcs.AI
Most harness-evolution gains come from overfitting or extra compute
Overfitting and test-time scaling explain most harness evolution gains, leaving little evidence of generalizable improvement.
Amazon, New York University · Oct 2026
- Research Labcs.LG
Coding agents solve more tasks when tool interfaces adapt during training
Co-evolving an LLM agent's policy and its executable harnesses through reinforcement learning improves performance over optimizing either component alone.
University of North Carolina at Chapel Hill, RIKEN · Oct 2026
- Big Techcs.AI
Optimizing AI agents for cost as well as quality improves both
Separating candidate promotion from final deployment choice helps agent-harness optimization preserve useful quality-cost trade-offs and produce better, cheaper solutions.
University College London, Pohang University of Science and Technology · Nov 2026
- Independentcs.CL
Small AI agents can handle computer tasks with clicks and code
Mage-VL-Cowork, a 4B hybrid computer-use agent, achieves 66.0% on OSWorld-Verified via evolved harness and five-stage training.
Nov 2026
- Big Techcs.LG
Learning the search harness improves frozen models’ scientific problem solving
HarnessTTT learns to generate executable harnesses at test time, allowing a frozen small executor to outperform fine-tuned systems across scientific discovery tasks.
University of Wisconsin-Madison, NVIDIA · Oct 2026
- Top Universitycs.MA
Simple market selection drives LLM agents to evolve unpriced traits
Market selection for lower LLM token use can indirectly collapse accuracy because token use and reasoning performance are correlated traits.
University of Leeds, Johns Hopkins University · Oct 2026
- Industrycs.SE
SWE-Bench Pro V2 repairs 480 flawed tasks and blocks agent exploits
SWE-Bench Pro V2 repairs or retires 480 of 731 tasks and hardens grading so frontier coding agents cannot game the benchmark.
Reflection AI, Scale AI · Oct 2026
- Big Techcs.CV
Compact reusable memory improves question answering over hour-long videos
Video-EMem encodes long videos once into compact time-anchored text and sparse images, then retrieves evidence per query, improving accuracy and cutting latency.
Zhejiang University, Microsoft Research Asia · Oct 2026
- Chinese Techcs.CL
Adaptive training harness keeps rubric rewards useful as policies improve
HarnessRL co-evolves task sampling, rollout guidance, and rubric criteria during RL training, beating baselines by 2.8-3.1 points on open-ended tasks.
Alibaba Token Hub, Alibaba Group, Université de Montréal · Oct 2026
- Big Techcs.AI
Multi-objective evolution yields stronger, more transferable agent harnesses
Harmony Harness jointly optimizes functionality and safety in LLM agent harnesses, outperforming single-objective baselines by over 10%.
Google Cloud AI Research, Google DeepMind · Oct 2026
- Research Labcs.AI
Agents Learn Reusable Control Code Instead of Rebuilding Context
Growing Harness learns reusable agent control code from task failures, reducing LLM calls by up to 91.8% while maintaining or improving task success.
Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, University of Chinese Academy of Sciences · Sept 2026
- Big Techcs.CL
Coding agents improve more when their model and harness co-evolve
Alternating self-proposed harness revisions with policy reinforcement learning improves coding-agent resolve rates beyond optimizing either component alone.
Microsoft Research, University of Virginia · Oct 2026
- Big Techcs.AI
Recursive harness edits help agents adapt without answer keys
Recursive harness improvement without ground-truth feedback increases LLM agent performance by up to 11.8 percentage points.
Google Cloud AI Research, Northwestern University · Oct 2026
- Big Techcs.AI
Joint harness search balances model accuracy, safety, and token use
Adobe Research · Sept 2026
- Big Techcs.AI
Verified self-improvement makes agent harness optimization more reliable
VERSE improves harness optimizers by letting them test edits and evolve their own verification tools.
MIT, Amazon · Oct 2026
- Top Universitycs.LGcode
Evidence-driven harness edits improve frozen GUI agents across benchmarks
GUI-HARVEST automatically improves GUI agent harnesses by diagnosing failures from repeated executions and generating reusable edits, boosting performance across models.
The Chinese University of Hong Kong, Shenzhen, Tianjin University · Oct 2026
- Chinese Techcs.CV
Video agents improve their own harnesses using unlabeled video
VideoEvoHarness evolves video agent harnesses from unlabeled videos without annotations or parameter updates, improving accuracy.
Institute of Automation, Chinese Academy of Sciences, University of Chinese Academy of Sciences · Oct 2026
- Big Techcs.LG
MILO co-evolves agent harnesses and the strategies that discover them
MILO co-evolves agent harnesses and search strategies via meta-evolutionary island orchestration, outperforming state-of-the-art methods.
Georgia Institute of Technology, AWS AI Labs · Oct 2026
- Research Labcs.AIcode
Evolved prover interfaces make theorem-solving agents faster and cheaper
An evolutionary method designs MCP servers for proof assistants, improving cost and solve rate.
IRIF, Université Paris Cité · Oct 2026
- Academiccs.AI
Framework improves AI agents by patching common failure patterns
Vestrum turns execution trace failures into scoped harness changes that improve performance on held-out tasks without retraining the model.
University of Georgia · Oct 2026
- Big Techcs.AIcode
Research-guided software evolution improves fixed-model agents on two benchmarks
ScholarEvolve automatically uses state-of-the-art research and topic modeling to guide agent harness evolution, improving task completion on AppWorld and Tau2-Bench.
University of California, Santa Barbara, Microsoft · Oct 2026
- Top Universitycs.AI
Tailoring agent harnesses per task beats one-size-fits-all optimization
Turbo Harness adapts global harnesses per instance using prior optimization artifacts, outperforming baselines across seven benchmarks.
Rutgers University, Red Hat AI Innovation · Oct 2026
- Top Universitycs.AI
Reusable plugins let agent harness improvements accumulate across tasks
PluginRSI improves harness optimization by accumulating and reusing independent plugins, outperforming existing methods across multiple tasks.
University of Science and Technology of China, Meituan · Sept 2026
- Independentcs.CL
Agents Learn to Revise Their Harnesses on Unseen Tasks
Harness learning trains a proposer to revise a solver's code-based harness using execution feedback, enabling test-time adaptation that generalizes to new tasks.
Sept 2026
- Big Tech
Evolved Agent Harnesses Improve Coverage but Fail to Consolidate Gains
Automatically evolved LLM agent harnesses improve completion and task coverage in hardware verification, but complementary gains do not reliably consolidate into one consistently superior harness.
NVIDIA · Sept 2026
- Top Universitycs.AI
Agents improve long-horizon performance by evolving how they manage context
Evolving context management policies from long-horizon trajectories improves long-horizon agent performance more effectively than evolving skills or using fixed context strategies.
Fudan University, Shanghai Key Laboratory of Data Science · Sept 2026
- Big Techcs.SE
Adaptive routing helps one language model handle mixed request types
Adaptive-GEPA learns a router and specialist programs to handle heterogeneous requests, outperforming single-program optimization.
University of Texas at Austin, University of California, Los Angeles · Oct 2026
- Independentcs.AI
Closed-loop development improves mobile agents across planning and tool use
Qwen-Planner-Agent uses AI agents to build and improve a mobile planner agent, outperforming prior systems on MobilePA-Bench.
Sept 2026
- Independentcs.SE
LLMs can build agent harnesses, but improvements transfer poorly
LLM-built agent harnesses trail human-engineered harnesses on code and search, match or exceed them on writing and ML experimentation, and evolve unreliably.
Sept 2026
- Research Labcs.SE
Cross-task failure diagnosis makes LLM agent harness training faster
Ecdysis aggregates failure evidence across task instances to train runtime harnesses for LLM agents, improving reasoning accuracy by 18.56%.
Chengdu Institute of Computer Applications, Chinese Academy of Sciences, University of Chinese Academy of Sciences · Sept 2026
- Chinese Techcs.SE
Self-evolving harness turns general AI agents into stronger RCA specialists
OpsHarness, a self-evolving harness, improves root cause analysis accuracy by 63.4% over a bare general agent.
The Chinese University of Hong Kong, Individual Researcher · Aug 2026
- Top Universitycs.CL
Generating Agent Harnesses on Demand Improves Models Across Benchmarks
JIT-Agent trains a meta-model to generate task-specific agent harnesses on the fly, improving off-the-shelf LLMs' agent performance.
LV-NUS Lab · Aug 2026
- Top Universitycs.AI
Evolved agent harnesses lift enterprise performance without retraining models
StarHarness evolves environment-specific agent harnesses, improving benchmark performance by 20-35 percentage points.
ServiceNow, Mila · Aug 2026
- Top Universitycs.AI
Behavior-aware checks make agent harness evolution cheaper and more reliable
HarnessLens evolves language-model agent harnesses by selectively verifying candidates on behavior-relevant tasks, improving held-out performance while reducing evaluation budget.
Fudan University, Shanghai Key Laboratory of Data Science · Aug 2026
- Top Universitycs.CL
Adaptive task selection cuts the cost of optimizing LLM agent harnesses
Adaptively selecting validation tasks by variance-weighted sampling and estimating full-set scores from subsets matches full-set harness search while cutting evaluation cost by 80%.
The University of Tokyo · Aug 2026
- Top Universitycs.AIcode
Re-evaluation shows harness evolution for agents may not outperform simple test-time scaling
Automatic harness evolution for LLM agents does not consistently beat simple test-time scaling and generalizes poorly to held-out tasks.
Allen Institute for AI, University of Washington · July 2026
- Independentcs.AI
Whole-system training improves general-purpose agents’ use of external tools
WEFT scales tool-use post-training for general-purpose agents by coupling whole-system interaction construction, execution-driven self-evolution, and stable post-training.
Sept 2026
- Chinese Techcs.AI
Self-improving context programs help frozen models understand long videos
Recursive search over executable context-construction programs improves long-video understanding with a frozen vision-language model.
Tencent · Aug 2026
- Chinese Techcs.AIcode
Evolutionary training harness co-evolves with LLM policies for RL
Co-evolving LLM policies with training-side diagnostic harnesses matches or exceeds human-engineered RL references across math, coding, and long-horizon software engineering.
Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Tongyi Lab , Alibaba Group · June 2026
- Big Techcs.AI
Self-supervised method improves agent harnesses using past trajectories
Retrospective Harness Optimization improves AI agent harness using past trajectories and self-preference, boosting SWE-Bench Pro pass rate from 59% to 78% without external labels.
City University of Hong Kong, Microsoft Research Asia · June 2026
- Academiccs.AI
Hidden bugs in evaluation code silently reorder AI agent rankings
Agent leaderboard scores are silently distorted by the grading, logging, cost and versioning code behind them; cheap audit checks can expose the reordering.
Shandong University · Nov 2026
- Big Techcs.CL
AI agents can improve long-context reasoning without costly retraining
LongCapHarness outperforms data-synthesis-based long-context reasoning methods with less than half the development cost.
Microsoft Research Asia · Nov 2026
- Big Techcs.AI
AI agents improve when their surrounding software is automatically redesigned
HarnessFlow achieves the highest mean test scores on six benchmarks by using MCTS-guided search to optimize LLM agent harnesses.
South China University of Technology, Fudan University · Nov 2026
- Top Universitycs.AI
Coding agents working in teams can outperform expert-written AI chip code
Evolving Agent Teams surpasses the expert-written FlashInfer MLA decode kernel, achieving 1.21x mean speedup.
University of California, Berkeley · Oct 2026
- Big Techcs.AI
Self-evolving agents trade plasticity for stability in continual learning streams.
Self-evolving LLM agents trade plasticity for stability: self-modification interferes across tasks, and memory retrieval causes collisions, so they are not complete continual learners.
Mila – Quebec AI Institute, Université de Montréal · Oct 2026
- Big Techcs.LG
Agents improve by distilling hindsight from their own interactions
Retrospective Self-Distillation lets agents evolve from their own trajectories using hindsight and cross-task precedents without external supervision.
Meta AI · Oct 2026
- Chinese Techcs.SE
Coding agents fully deliver enterprise PRD requirements only 14 percent of the time
Coding agents often implement individual pieces but rarely complete enterprise PRDs, with missing functionality and integration as the main failure modes.
Zhejiang University, Alibaba Taobao & Tmall Group · Oct 2026
- Big Techcs.AI
Coevolving specialized models and LLM agents for autonomous self-improvement
Heterogeneous Agentic Coevolution jointly evolves specialized foundation models and LLM agents through reciprocal learning to improve domain-specific performance.
Meta AI, University of Virginia · Oct 2026
- Big Techcs.AI
Agent evolvers can learn their own search strategies across tasks
A learned campaign policy lets agent evolvers organize their own search and match or exceed hand-designed loops while transferring across tasks.
AWS AI Labs, Georgia Institute of Technology · Oct 2026
- Chinese Techcs.CV
Benchmark and agent for verifying images against real-world facts
Persistent, state-guided verification detects image-world factual conflicts better than direct or retrieval-augmented judgment on evaluated 8B vision-language models.
Ant Group, Tsinghua University · Oct 2026
- Chinese Techcs.LG
Contextual bandits select reusable LLM workflows with less training overhead
CB-Orchestrator beats baselines on five benchmarks and cuts MATH training token overhead by over 40% via contextual bandit workflow selection.
The Chinese University of Hong Kong, Shenzhen, Huawei Technologies · Oct 2026
- Top Universitycs.AI
Co-evolving agent harnesses improve abstention without sacrificing task completion
Co-evolving an agent harness with adversarially mutated environments improves abstention, task completion, cross-model transfer, and cost efficiency in tool-using LLM agents.
University of Washington, University of Leeds · Oct 2026
- Chinese Techcs.LG
Refining rejected candidates makes AI system optimization more efficient
Mara Chain retains and refines rejected AI system candidates instead of discarding them, improving performance with fewer evaluations.
Ant Group, Beijing Intelligent Game and Decision Lab · Sept 2026
- AI Startupcs.AI
Multi-agent workflows enable models to recursively improve on open-ended tasks
Multi-agent self-supervision enables recursive self-improvement of language models on open-ended tasks, yielding 1.2-1.6x higher performance per token.
UC Berkeley, Sakana AI · Oct 2026
- Chinese Techcs.LG
Validation-gated co-evolution improves agent models and execution harnesses
Alternating model training with checkpoint-specific, validation-gated harness updates outperforms weight-only training and ungated alternation on two agent benchmarks.
ICT AI Competence Center, Huawei Technologies Co., Ltd., Shanghai Jiao Tong University · Sept 2026
- Independentcs.CL
Models struggle to improve themselves from vague capability goals
Self-evolution from vague goals leads to mismatched training data and non-transferable improvements.
Sept 2026
- Academiccs.AI
Layered agent harnesses improve software over repeated autonomous development cycles
HoH enables coding agents to continually improve software in autonomous development, achieving 52.25% average gain over standalone harnesses.
Shanghai Artificial Intelligence Laboratory · Sept 2026
- Big Techcs.AI
Skill evolution improves agent performance in image generation workflows
Self-evolving skill libraries improve agent reliability in recurring image generation workflow construction.
University of Pennsylvania, Nvidia · July 2026
- Academiccs.LG
AI agents can drop from 85% to 19% success with rearranged information
A policy trained under one agent harness secretly encodes that harness's action preferences, so changing the interface can destroy performance even when optimal actions stay identical.
The Hong Kong University of Science and Technology (Guangzhou), The Hong Kong University of Science and Technology · Oct 2026
- Big Techcs.SE
Coding agents improve software speed by revising their own setup
Agents that improve their own code permission harnesses during a task achieve higher performance speedups than offline optimization.
Nanjing University, Zhejiang University · Nov 2026
- Chinese Techcs.AI
Self-improving AI agents often lose their gains on harder, different tasks
Current self-improving agents' gains are inconsistent across generalization levels.
Shanghai Jiao Tong University, Theseus Labs · Nov 2026
- Big Techcs.RO
Action-aware embeddings retrieve better robot experiences for future actions
Robota-Embed jointly encodes vision, language, and action for robot experience retrieval, outperforming action-free embeddings.
NVIDIA, MIT · Oct 2026
Concepts are extracted from each paper and reused across the corpus, so this page grows on its own as the desk reads.