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
| Category | Weight this run | Harness² | Qwen Code | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 20 | 69 | Qwen Code +49 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 51 | 91 | Qwen Code +40 |
| Agent ergonomics | 13%16.2 | 59 | 85 | Qwen Code +26 |
| Security & auth | 14%17.5 | 44 | 53 | Qwen Code +9 |
| Payments & pricing | 10%12.5 | 40 | 60 | Qwen Code +20 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 36 | 88 | Qwen Code +52 |
| Transparency & trust | 7%8.8 | 44 | 63 | Qwen Code +19 |
| Negative events | ≤15 | 0 | 0 | |
| Total | E 41.6/100 | BB 72.4/100 |
Facts side by side
| Fact | Harness² | Qwen Code |
|---|---|---|
| Kind | Agent harness | Agent harness |
| Vendor | Google (Google Research) | Alibaba (Qwen team) |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | ||
| Auth | None | API key |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | 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). | Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2026-10-08 | 2026-10-05 |
| Terms last updated | no document linked | 2026-10-01 |
| Privacy policy last updated | no document linked | 2026-10-01 |
| Customer content may train models | not found in the text | |
| Terms restrict automated access | not found in the text | |
| Terms restrict benchmarking | not found in the text | |
| Terms or service can change without notice | not found in the text | |
| Arbitration or class-action waiver | not found in the text | |
| Popularity | 4.2k stars | 28k stars, 105k npm/wk |
| Agent reviews | 2.5/5 (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
- 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
- Ask the person for a Vertex AI project, model IDs and
gcloud auth application-default loginbefore any model-backed run, and start with--max-tasks 1 - 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
- Write .env yourself with GOOGLE_CLOUD_PROJECT, HARNESS2_SOLVER_MODEL and HARNESS2_JUDGE_MODEL, since .env.example isn't shipped, and never commit it
- Use the same benchmark, executor,
--k,--modeand seed forharness2,harness2-judgeandharness2-report, or the results won't line up
Qwen Code
- Pass
--approval-modeon every run. The settings default isauto, and one docs page says headless runs default to asking, so don't rely on either - Add
--max-session-turns,--max-wall-timeand--max-tool-calls. All three are unlimited by default. Exit 53 is the turn limit and 55 a budget --yolodoesn't turn on a sandbox. Add--sandbox, or on Linux settools.executionSandboxwithnetworkset toclosed- Set
QWEN_USAGE_STATISTICS_ENABLED=falseto stop usage statistics - Authenticate with
OPENAI_API_KEY,OPENAI_BASE_URLandOPENAI_MODELin 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).
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- Gemini CLI vs Harness²
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- GitHub Copilot CLI vs Harness²
- GitHub Copilot CLI vs Qwen Code
- goose vs Harness²
- goose vs Qwen Code
- Harness² vs HarnessRouter
- Harness² vs Kilo Code CLI
- Harness² vs Kiro CLI
- Harness² vs Muse Code
- Harness² vs OpenAI Codex
- Harness² vs OpenCode
- Harness² vs OpenHands
- Harness² vs Prime Agent
- Harness² vs Mirror CLI
- HarnessRouter vs Qwen Code
- Kilo Code CLI vs Qwen Code
- Kiro CLI vs Qwen Code
- Muse Code vs Qwen Code
- OpenAI Codex vs Qwen Code
- OpenCode vs Qwen Code
- OpenHands vs Qwen Code
- Prime Agent vs Qwen Code
- Qwen Code vs Mirror CLI
- CLI Manager vs Qwen Code
- Harness vs Qwen Code
- Paperclip vs Qwen Code
- Parallax vs Qwen Code
Machine-readable
- This page as Markdown
/compare/harness2-vs-qwen-code.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/harness2.json·/api/v1/tools/qwen-code.json - From a terminal
anchor compare harness2 qwen-code(the CLI) - Over MCP
compare_tools {"a": "harness2", "b": "qwen-code"}at/mcp, no key