18 papers

Agent Architecture & Harnesses

The loop, the harness, and the plumbing that turns a model into a working agent.

Papers
18
Read time
4.9h
Avg length
16m
01
Agent Architecture & Harnesses

ReAct: Synergizing Reasoning and Acting in Language Models

Let an LLM interleave free-text "thoughts" with real tool actions in a single prompt loop, and it plans, grounds itself in the world, and recovers from mistakes far better than reasoning-only or acting-only agents — this is the paper that defined the agent loop you already use.

YAO, ZHAO, YU, DU, SHAFRAN, NARASIMHAN, CAO (PRINCETON + GOOGLE BRAIN) · ICLR 2023
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16 min
Source
arXiv:2210.03629
02
Agent Architecture & Harnesses

Agent Harness Engineering: A Survey

The reliability of an AI agent depends as much on the plumbing wrapped around the model — sandboxes, tools, memory, control loops, tracing, evals, and guardrails — as on the model itself, and this survey names that plumbing "the harness," gives it a seven-part map (ETCLOVG), and grades 170+ real projects against it.

LI, XIAO, ZHANG, LIU, ET AL. (CMU, UAB, TULANE, YALE, AMAZON, STANFORD + OTHERS) · 2026
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22 min
Source
arXiv:2507.15330
03
Agent Architecture & Harnesses

Dive into Claude Code: The Design Space of Today's and Future AI Agent Systems

A line-by-line reverse-engineering of Claude Code's TypeScript source that shows a production coding agent is not a clever model loop — it is a thin reasoning core (~1.6% of the code) wrapped in a dense deterministic harness for permissions, context compaction, extensibility, delegation, and persistence, and that harness is where all the real engineering (and your build/moat opportunity) lives.

JIACHENG LIU, XIAOHAN ZHAO, XINYI SHANG, ZHIQIANG SHEN (VILA LAB, MBZUAI / UCL) · APR 2026
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22 min
Source
arXiv:2604.14228
04
Agent Architecture & Harnesses

A Practical Guide for Designing, Developing, and Deploying Production-Grade Agentic AI Workflows

A field-tested checklist of nine engineering rules that turn flaky LLM-agent demos into deterministic, observable, deployable production systems — distilled from building a real news-to-podcast pipeline.

BANDARA, GORE, FOYTIK, SHETTY, MUKKAMALA, ET AL. (OLD DOMINION U., DELOITTE, FIU, NTU, EFFECTZ.AI) · DEC 2025
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16 min
Source
arXiv:2512.08769
05
Agent Architecture & Harnesses

A Practical Approach for Building Production-Grade Conversational Agents with Workflow Graphs

Instead of stuffing every business rule into one giant system prompt, Kakao splits their e-commerce agent into a directed graph of small, single-purpose LLM states — then fine-tunes on the resulting conversations with a masking trick that stops each state's training data from contaminating the others.

CHIWAN PARK, WONJUN JANG, DAERYONG KIM, ET AL. (KAKAO) · 2025
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15 min
Source
arXiv:2505.23006
06
Agent Architecture & Harnesses

From Agent Behaviour to Agent-Friendly Documentation - An Empirical Study of How Coding Agents Discover, Read, and Write Technical Documentation

When you actually watch 557 real coding-agent sessions instead of guessing, agents spend 60.5% of their documentation time on files written *for* agents (AGENTS.md, CLAUDE.md, plans, `thoughts/`) and only 1.3% on API references — and almost none of the "read the docs, then write the code, then check the docs" behaviour everyone assumes actually shows up in the traces.

ZHIJUN GAO, JING CHEN (PEKING UNIVERSITY) · ARXIV PREPRINT, AUG 2026 (CS.SE)
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22 min
Source
arXiv:2608.20195
07
Agent Architecture & Harnesses

JIT-Agent: Scaling Harness Intelligence via Just-in-Time Harness Evolution

JIT-Agent is a trained "meta-agent" that, given a task, writes a bespoke agent

ZHANG, LU, XIE, ET AL. (LV-NUS LAB) · 2026
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15 min
Source
arXiv:2608.25593
08
Agent Architecture & Harnesses

Meta-Harness: End-to-End Optimization of Model Harnesses

Meta-Harness points a coding agent at a folder full of every previous harness's source code, scores, and raw execution logs, and lets it rewrite the harness itself — instead of hand-tuning prompts, it automates the harness-engineering job directly.

YOONHO LEE, ROSHEN NAIR, QIZHENG ZHANG, OMAR KHATTAB, KANGWOOK LEE, CHELSEA FINN (STANFORD / MIT / KRAFTON) · ARXIV PREPRINT, 30 MAR 2026
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14 min
Source
arXiv:2603.28052
09
Agent Architecture & Harnesses

Model or Harness? An Interaction-Centric Taxonomy for Localizing Agent Failures

When your agent fails, this paper gives you a fixed vocabulary for saying *which two parts of the system were talking to each other* and *which of the two was actually wrong* — so the fix lands on the model, the scaffolding, the environment, or the test, instead of on whatever you guessed.

HARSH RAJ, VIPUL GUPTA, ANAS MAHMOUD, RAZVAN-GABRIEL DUMITRU, DARVIN YI, AAKASH SABHARWAL, YUNZHONG HE (SCALE AI) · ARXIV PREPRINT, 30 JUL 2026
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18 min
Source
arXiv:2607.28802
10
Agent Architecture & Harnesses

OpenJarvis: Personal AI, On Personal Devices

Swapping a cloud model for a local one breaks a personal AI assistant because the whole stack was built around the cloud model, not just the model; OpenJarvis turns the entire stack into an editable, searchable object so a cloud "teacher" can rebuild it around the local model instead.

SAAD-FALCON, NARAYAN, MANIHANI, BHATHAL, SHANDILYA, AKENGIN, BO, PARK, HART, COSTELLO, LI, RÉ, MIRHOSEINI (STANFORD / LAMBDA LABS) · PREPRINT
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14 min
Source
arXiv:2605.17172
11
Agent Architecture & Harnesses

Self-Refine: Iterative Refinement with Self-Feedback

Same LLM, three hats — write a draft, critique your own draft, rewrite it — looped a few times, and you get 5-40% better outputs with zero training, fine-tuning, or extra models.

MADAAN, TANDON, GUPTA, ET AL. (CMU / AI2 / UW / NVIDIA / UCSD / GOOGLE RESEARCH)
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14 min
Source
arXiv:2303.17651
12
Agent Architecture & Harnesses

Tendem: A Hybrid AI+Human Platform

Tendem runs an AI agent through a plan-act-observe-verify loop and only hands work to a paid human expert at specific "step gates" where risk or uncertainty is high, and on 94 real freelance-style tasks that combination beats both a pure AI agent and pure human freelancers on quality, speed, and cost at once.

TOLOKA TEAM (CHERNYSHEV, ARTEMOVA, ZHUKOV, NERUSH, FEDOROVA, REPIK, SHAPOVALOVA, SUKHOROSOV, DOBROVOLSKII, MIKHAILOVA, TILGA) · NOV 2025
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9 min
Source
arXiv:2602.01119
13
Agent Architecture & Harnesses

The Scaffolding Matters More Than the Interface

They ran the same six-step GitHub task through seven agent harnesses, five models, and both tool interfaces, and found that which harness you pick changes your bill by up to 139×, while MCP-versus-CLI does not reliably change it at all.

MARC ALIER FORMENT, MARÍA JOSÉ CASAÑ GUERRERO, FRANCISCO JOSÉ GARCÍA-PEÑALVO, JUANAN PEREIRA · UPC / USAL / UPV-EHU, 2026
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22 min
Source
arXiv:2608.08654
14
Agent Architecture & Harnesses

Toolformer: Language Models Can Teach Themselves to Use Tools

A 6.7B model teaches itself, with no human labels, exactly when to call a calculator, search engine, translator, QA system, or calendar mid-sentence — by generating its own API calls, keeping only the ones that measurably make its next-word predictions easier, and fine-tuning on that self-curated dataset.

SCHICK, DWIVEDI-YU, DESSÌ, LOMELI, ZETTLEMOYER, CANCEDDA, RAILEANU, SCIALOM (META AI) · 2023
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10 min
Source
arXiv:2302.04761
15
Agent Architecture & Harnesses

Toward Training Superintelligent Software Agents through Self-Play SWE-RL

A single coding LLM teaches itself to fix bugs by also learning to *create* bugs — playing both attacker and defender against itself inside real codebases — and gets steadily better at solving real GitHub issues it was never trained on.

YUXIANG WEI, ZHIQING SUN, EMILY MCMILIN, JONAS GEHRING, ET AL. (META FAIR, META TBD LAB, UIUC, CMU) · DEC 2025
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22 min
Source
arXiv:2512.18552
16
Agent Architecture & Harnesses

Voyager: An Open-Ended Embodied Agent with Large Language Models

Voyager is a Minecraft agent that never stops playing — it picks its own next goal, writes JavaScript to pursue it, keeps every script that worked in a growing skill library, and uses that library to learn faster and faster, all without ever touching GPT-4's weights.

WANG, XIE, JIANG, MANDLEKAR, XIAO, ZHU, FAN, ANANDKUMAR (NVIDIA, CALTECH, UT AUSTIN, STANFORD, UW MADISON) · OCT 2023
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14 min
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arXiv:2305.16291
17
Agent Architecture & Harnesses

Web World Models

Instead of letting an LLM hallucinate an entire game/world, define the world's rules and state in ordinary web code and let the model only fill in the flavor — giving you infinite, controllable environments with no database.

FENG, ZHANG, ZHANG, LU, LIU, WANG (PRINCETON AI2 LAB / UCLA / UPENN) · DEC 2025
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16 min
Source
arXiv:2512.23676
18
Agent Architecture & Harnesses

WebGPT: Browser-assisted question-answering with human feedback

OpenAI gave GPT-3 a text-only web browser and a "quote" button, then used human preference data to train it to search, click, and cite its way to answers that beat human-written Reddit answers 69% of the time.

NAKANO, HILTON, KIM, HESSE, SAUNDERS, ET AL. (OPENAI) · NEURIPS-ERA PREPRINT, 2021 (V3: JUNE 2022)
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14 min
Source
arXiv:2112.09332