---
title: 'Agentless: Demystifying LLM-based Software Engineering Agents'
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
license_note: 'paper is CC BY 4.0 (verified on arXiv abs page 2026-11-11; icon by-4.0.png, http://creativecommons.org/licenses/by/4.0/); note is our own summary'
source: https://iinventedlight.com/library/notes/2407-01489-agentless.md
source_license: 'CC BY 4.0'
attribution: 'Summary by iinventedlight (AI-assisted). Source: Chunqiu Steven Xia, Yinlin Deng, Soren Dunn, Lingming Zhang, Agentless: Demystifying LLM-based Software Engineering Agents (CC BY 4.0).'
author: 'iinventedlight (AI-assisted)'
date: 2026-11-11
status: published
approved_by: "Cole Withington, 2026-11-11 20:58 PT, Grok Bot chat widget t1717s7407: \"Publish all 100 including the LLMs Encode Clinical Knowledge note\""
checked_on: 2026-11-11
as_of: 2026-11-11
confidence: medium
untested: 'Not reproduced. Abs page and HTML key sections read 2026-11-11. Named code URLs checked; code not run.'
category: arxiv
topic_area: 'ai-research: agents'
tags: arxiv, agents, software-engineering
arxiv_id: 2407.01489
alias: 2407.01489-agentless
sources:
  - id: S1
    title: 'Agentless: Demystifying LLM-based Software Engineering Agents'
    publisher: arXiv
    authors: 'Chunqiu Steven Xia, Yinlin Deng, Soren Dunn, Lingming Zhang'
    url: https://arxiv.org/abs/2407.01489
    version_read: 'v2 (29 Oct 2024)'
    accessed: 2026-11-11
    license: 'CC BY 4.0'
---
# Agentless: Demystifying LLM-based Software Engineering Agents

## Summary
Agentless is a software-repair pipeline that uses a three-phase process of localization, repair, and patch validation, without letting the model decide future actions or operate complex tools. On SWE-bench Lite, the authors report that this simpler approach achieved 32.00% (96 correct fixes) at a cost of $0.70, which they say was the highest performance among the open-source software agents they compared, at a low cost. They also construct SWE-bench Lite-S by excluding such problematic issues to perform more rigorous evaluation and comparison. [S1]

## Claims
- id: C1
  claim: 'Agentless uses a three-phase process of localization, repair, and patch validation.'
  source: S1
  evidence: "a simplistic three-phase process of localization, repair, and patch validation"
- id: C2
  claim: 'On SWE-bench Lite they report 32.00% (96 correct fixes) at a cost of $0.70.'
  source: S1
  evidence: "the highest performance (32.00%, 96 correct fixes) and low cost ($0.70)"
- id: C3
  claim: 'They have open-sourced Agentless on GitHub.'
  source: S1
  evidence: "We have open-sourced Agentless at: https://github.com/OpenAutoCoder/Agentless"

## Verification
- Code available: Paper: https://github.com/OpenAutoCoder/Agentless, which returned HTTP 200 on 2026-11-11. Not run.
- Reproduced: not reproduced (2026-11-11). Code not run.
- Related work: Live notes ao-coding-agentless-vs-agent-platforms and 2310-06770-swe-bench. This is the paper-verification note for Agentless itself.
- Limits: The 32.00% figure and cost are from the authors' SWE-bench Lite comparison in the v2 paper (revised 29 Oct 2024) and may not hold against later agents or later models. Lite-S is their own filtered subset.
- License: CC BY 4.0 on the abs page (2026-11-11; icon by-4.0.png; http://creativecommons.org/licenses/by/4.0/). Submitted 1 Jul 2024 (v1); last revised 29 Oct 2024 (v2). Sources: [S1] https://arxiv.org/abs/2407.01489, v2 (29 Oct 2024). checked_on: 2026-11-11.

## When to apply
Use when comparing a simple localize-and-repair pipeline with heavier software-engineering agents.

## Facts
- id: F1
  claim: 'Agentless is a localization, repair, and patch-validation pipeline that does not use a heavy agent scaffold.'
  confidence: medium
  date: 2026-11-11
  sources: [S1]
  license: CC BY 4.0
- id: F2
  claim: 'The authors report 32.00% (96 correct fixes) on SWE-bench Lite at a cost of $0.70 in their comparison.'
  confidence: medium
  date: 2026-11-11
  sources: [S1]
  license: CC BY 4.0
- id: F3
  claim: 'They also construct SWE-bench Lite-S by excluding issues they judged problematic.'
  confidence: medium
  date: 2026-11-11
  sources: [S1]
  license: CC BY 4.0

## Sources
- [S1] arXiv 2407.01489, https://arxiv.org/abs/2407.01489. License: CC BY 4.0. v2 (29 Oct 2024). Accessed 2026-11-11.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted). Paper is CC BY 4.0.

---

Agents: [/agents.md](/agents.md) | [/.well-known/agent-library.json](/.well-known/agent-library.json).