Harness Bench

What it does

When your agent uses it

• Tasks that involve Project scaffolding

Example prompts

• “/harness-bench”

Requirements

• Pre-approved tools (allowed-tools): Bash

Workflow steps

4 steps, taken from the first numbered list in SKILL.md.

1. 1Resolve --repo path; reject if missing.
2. 2Shell to metaharness-darwin bench create [--out ].
3. 3Default output path: /.metaharness/bench/suite.json (chosen by upstream).
4. 4Suite shape (per upstream): array of { input, expectedOutput, weight } tasks

What it can do on your machine

Read from SKILL.md and the folder at commit 6051f67. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Bash

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • npm

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md. Its commands use npm, which can reach the network depending on how they are called.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Harness Bench loads about 586 tokens when it runs. Until then it costs about 102 tokens; SKILL.md has 217 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~102

When it runs · the whole SKILL.md, loaded when a task matches

~586

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

• NotePre-approves every shell command (allowed-tools: Bash)SKILL.md

  allowed-tools: Bash

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from ruvnet/ruflo at commit 6051f67, republished under its MIT licence (© ruvnet). 217 words, ~586 tokens.

name

harness-bench

description

Manage `@metaharness/darwin` bench suites — `bench create <repo>` scaffolds a JSON suite from a repo's test corpus; `bench verify <suite.json>` checks suite well-formedness. Bench suites are the fixed evaluation corpora that `harness-evolve --bench <suite.json>` scores variants against, decoupling evolution from the repo's natural tests. Degrades gracefully when @metaharness/darwin is absent.

allowed-tools

Bash

argument-hint

--op create --repo <path> [--out <path>] | --op verify --suite <path>

{
  "success": true,
  "data": {
    "op": "verify",
    "taskCount": 42,
    "wellFormed": true,
    "durationMs": 870
  }
}

© ruvnet, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in plugins/ruflo-metaharness/skills/harness-bench of ruvnet/ruflo.

Open the folder on GitHubat commit 6051f67

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in ruvnet/ruflo, which our catalogue first saw on October 7, 2026.

• majiayu000/claude-skill-registryskills/bash/harness-bench