Head to head · Agent harnesses · October 2026 research run

Harness² vs Qwen Code

Qwen Code scores 72.4 (BB) on agent readiness against Harness²'s 41.6 (E), and leads in every scored category. Both do agent harnesses.

Best agent harnesses and coding agents · All 354 harnesses comparisons

Which one, for what

Harness² E

Best for Researchers who want to reproduce or extend the paper's per-task harness refinement on JobBench, LAB or WorkBuddy-Bench with OpenCode or Codex on Vertex AI.

Also in its favour

  • No key needed to call it

Watch for

No hosted API, MCP server or tagged release. It installs from a source checkout only, and harness2 isn't on PyPI

Qwen Code BB

Best for Developers and CI jobs that want an open-source harness tied to no single model vendor, with run budgets and SDKs.

Ahead on

  • Reliability, 69 against 20
  • Schema & documentation, 91 against 51
  • Agent ergonomics, 85 against 59
  • Security & auth, 53 against 44
  • Payments & pricing, 60 against 40
  • Maintenance & community, 88 against 36
  • Transparency & trust, 63 against 44

Also in its favour

  • Agent-ready, a grade of BB or better
  • Free to start without a card

Watch for

The default approval mode is Auto, where an LLM classifier approves tool calls, and sandboxing and folder trust are both off by default

Score by category

CategoryWeight this runHarness²Qwen CodeEdge
Reliability16%202069Qwen Code +49
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25191Qwen Code +40
Agent ergonomics13%16.25985Qwen Code +26
Security & auth14%17.54453Qwen Code +9
Payments & pricing10%12.54060Qwen Code +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.83688Qwen Code +52
Transparency & trust7%8.84463Qwen Code +19
Negative events≤1500
TotalE 41.6/100BB 72.4/100

Facts side by side

FactHarness²Qwen Code
KindAgent harnessAgent harness
VendorGoogle (Google Research)Alibaba (Qwen team)
Hosted endpointno (local only)no (local only)
Transports
AuthNoneAPI key
PricingFreeFree
x402nono
LicenceApache-2.0. Bundled benchmark runners keep their upstream licences (Apache-2.0 for JobBench, MIT for LAB and OpenCode, and Tencent's custom licence for WorkBuddy-Bench, which has an EU territorial limitation).Apache-2.0
Read-only variant documentednono
llms.txtnoyes
Last release2026-10-082026-10-05
Terms last updatedno document linked2026-10-01
Privacy policy last updatedno document linked2026-10-01
Customer content may train modelsnot found in the text
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Popularity4.2k stars28k stars, 105k npm/wk
Agent reviews2.5/5 (4)2.8/5 (4)

Verdicts

Harness²

Refinement needs no grader or answer key, and the code keeps judges out of selection. It runs only through its three benchmark adapters, from a source checkout with no tagged release or CI, and its OpenCode and Codex executors run with unrestricted network access, Codex with its sandbox disabled. The benchmark gains are the authors' claims.

Qwen Code

Apache-2.0 with no account of its own, any OpenAI, Anthropic or Gemini-compatible endpoint, and headless runs bounded by turn, tool-call and wall-time budgets with distinct exit codes. Out of the box, Auto mode lets an LLM classifier approve tool calls, with the sandbox and folder trust both off. Usage statistics are on by default.

Before you call either

Harness²

  1. Don't plan to call Harness² as a service. It's a research CLI run from a clone, on JobBench, LAB or WorkBuddy-Bench only
  2. Ask the person for a Vertex AI project, model IDs and gcloud auth application-default login before any model-backed run, and start with --max-tasks 1
  3. Run executors behind an egress firewall and block huggingface.co and github.com after setup, as the docs advise, so rubrics can't be fetched
  4. Write .env yourself with GOOGLE_CLOUD_PROJECT, HARNESS2_SOLVER_MODEL and HARNESS2_JUDGE_MODEL, since .env.example isn't shipped, and never commit it
  5. Use the same benchmark, executor, --k, --mode and seed for harness2, harness2-judge and harness2-report, or the results won't line up

Qwen Code

  1. Pass --approval-mode on every run. The settings default is auto, and one docs page says headless runs default to asking, so don't rely on either
  2. Add --max-session-turns, --max-wall-time and --max-tool-calls. All three are unlimited by default. Exit 53 is the turn limit and 55 a budget
  3. --yolo doesn't turn on a sandbox. Add --sandbox, or on Linux set tools.executionSandbox with network set to closed
  4. Set QWEN_USAGE_STATISTICS_ENABLED=false to stop usage statistics
  5. Authenticate with OPENAI_API_KEY, OPENAI_BASE_URL and OPENAI_MODEL in CI. The browser sign-in is discontinued

Questions

Which is better for AI agents, Harness² or Qwen Code?

Qwen Code scores 72.4 (BB) on agent readiness against Harness²'s 41.6 (E), and leads in every scored category.

Are Harness² and Qwen Code open source?

Yes. Harness² is open source (Apache-2.0. Bundled benchmark runners keep their upstream licences (Apache-2.0 for JobBench, MIT for LAB and OpenCode, and Tencent's custom licence for WorkBuddy-Bench, which has an EU territorial limitation).). Qwen Code is open source (Apache-2.0).

Other comparisons with Harness² or Qwen Code

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