gan-style-harness

gan-style-harness is a skill for Claude Code, Codex from majiang213/OpenClaw-MAS. It costs 33 tokens per session (2,847 once invoked), scanned A, a copy of gan-style-harness, MIT.

A multi-agent method for building applications in which one agent creates the work and another independently evaluates it.

In plain words
What is it for?
Use it for complete applications, visually demanding frontend work, and projects that need repeated review of working features and design.
Why use it?
Separate evaluation exposes quality problems that the creating agent may overlook, especially in larger application projects.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument; mentions Claude Code.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is ./scripts/gan-harness.sh "Build a music streaming dashboard".

Good fit Use it for complete applications, visually demanding frontend work, and projects that need repeated review of working features and design.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/majiang213/OpenClaw-MAS
agentmods
npx agentmods add skills/majiang213/openclaw-mas/gan-style-harness

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for gan-style-harness

README.md
[![agentmods](https://agentmods.dev/badge/skills/majiang213/openclaw-mas/gan-style-harness/github.svg)](https://agentmods.dev/skills/majiang213/openclaw-mas/gan-style-harness)
Your own site
<a href="https://agentmods.dev/skills/majiang213/openclaw-mas/gan-style-harness"><img src="https://agentmods.dev/badge/skills/majiang213/openclaw-mas/gan-style-harness/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for gan-style-harness

Your own site · 80×15
<a href="https://agentmods.dev/skills/majiang213/openclaw-mas/gan-style-harness"><img src="https://agentmods.dev/badge/skills/majiang213/openclaw-mas/gan-style-harness.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,847 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 92% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00033 $0.02847
Opus 5 $0.00016 $0.01424
Sonnet 5 $0.00007 $0.00569
Haiku 4.5 $0.00003 $0.00285

Measured 7d ago against content hash 2ce1e3d2579e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

gan-style-harness scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

92% identical to gan-style-harness — 27 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

ecc-skills/gan-style-harness/SKILL.md · 279 lines

How it starts

The opening of the file, as written. The whole thing — 279 lines — stays where its author put it; the contents beside it link to each section on GitHub.

GAN-Style Harness Skill

Inspired by Anthropic's Harness Design for Long-Running Application Development (March 24, 2026)

A multi-agent harness that separates generation from evaluation, creating an adversarial feedback loop that drives quality far beyond what a single agent can achieve.

Core Insight

When asked to evaluate their own work, agents are pathological optimists — they praise mediocre output and talk themselves out of legitimate issues. But engineering a separate evaluator to be ruthlessly strict is far more tractable than teaching a generator to self-critique.

This is the same dynamic as GANs (Generative Adversarial Networks): the Generator produces, the Evaluator critiques, and that feedback drives the next iteration.

When to Use

  • Building complete applications from a one-line prompt
  • Frontend design tasks requiring high visual quality
  • Full-stack projects that need working features, not just code
  • Any task where "AI slop" aesthetics are unacceptable
  • Projects where you want to invest $50-200 for production-quality output

When NOT to Use

  • Quick single-file fixes (use standard claude -p)
  • Tasks with tight budget constraints (<$10)
  • Simple refactoring (use de-sloppify pattern instead)
  • Tasks that are already well-specified with tests (use TDD workflow)

Architecture

                    ┌─────────────┐
                    │   PLANNER   │
                    │  (Opus 4.6) │
                    └──────┬──────┘
                           │ Product Spec
                           │ (features, sprints, design direction)
                           ▼
              ┌────────────────────────┐
              │                        │
              │   GENERATOR-EVALUATOR  │
              │      FEEDBACK LOOP     │
              │                        │
              │  ┌──────────┐          │
              │  │GENERATOR │--build-->│──┐
              │  │(Opus 4.6)│          │  │
              │  └────▲─────┘          │  │
              │       │                │  │ live app
              │    feedback             │  │
              │       │                │  │
              │  ┌────┴─────┐          │  │
              │  │EVALUATOR │<-test----│──┘
              │  │(Opus 4.6)│          │
              │  │+Playwright│         │
              │  └──────────┘          │
              │                        │
              │   5-15 iterations      │
              └────────────────────────┘

Read the full file on GitHub · 279 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 279 lines · 33 tokens per session scan A 2ce1e3d2579e

Subscribe to this mod's changes

gan-style-harness is a skill published in the GitHub repository majiang213/OpenClaw-MAS (5 stars, last pushed 5mo ago), licensed MIT. It adds 33 tokens to every session and 2,847 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to gan-style-harness, differing in 27 lines, and is treated as a copy.