harness-init-runner

harness-init-runner is a skill for Claude Code, Codex from rexleimo/aios. It costs 70 tokens per session (782 once invoked), scanned A, original, MIT.

A repo-local Node.js runner for long-running coding agents. It creates a small harness inside a project without depending on the larger AIOS workspace.

In plain words
What is it for?
Use it in a Node.js repository to create the harness runner, provider command settings, runtime storage, and commands for running or checking the harness.
Why use it?
It provides a portable way to run agents and keep their runtime files in the project. This avoids setting up the full AIOS layout when a lightweight harness is enough.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/rexleimo/aios/harness-init-runner
Any agent
npx skills add rexleimo/aios --skill harness-init-runner
Clone the repo
git clone --depth 1 https://github.com/rexleimo/aios

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 harness-init-runner

README.md
[![agentmods](https://agentmods.dev/badge/skills/rexleimo/aios/harness-init-runner.svg)](https://agentmods.dev/skills/rexleimo/aios/harness-init-runner)
Your own site
<a href="https://agentmods.dev/skills/rexleimo/aios/harness-init-runner"><img src="https://agentmods.dev/badge/skills/rexleimo/aios/harness-init-runner.svg" alt="Measured on agentmods" height="20"></a>
Per session 70 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 782 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 $0.00070 $0.00782
Opus 5 $0.00035 $0.00391
Sonnet 5 $0.00014 $0.00156
Haiku 4.5 $0.00007 $0.00078

Measured 4d ago against content hash d0face01ef96, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

harness-init-runner 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 4d ago.

The scan reads SKILL.md. This mod also ships 12 executable files (assets/template/harness/config.schema.mjs, assets/template/harness/doctor.mjs, assets/template/harness/lib/checkpoint.mjs, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skill-sources/harness-init-runner/SKILL.md · 68 lines

How it starts

The opening of the file, as written. The whole thing — 68 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Harness Init Runner (Node.js)

Working directory: any Node.js repo with package.json

Create a portable long-running-agent harness inside the current repo (Node.js), without pulling in the full AIOS workspace layout.

When to use (even if AIOS is installed)

  • Use this when you want a repo-local, lightweight harness/ runner that works across Codex / Claude Code / Gemini / opencode.
  • If you already use AIOS, you may not need this. However it can coexist: this skill creates harness/ + /.harness/ and does not depend on scripts/aios.mjs.

What this skill generates (repo root)

  • harness/ (runner code)
  • harness.config.json (provider command templates)
  • /.harness/ (runtime artifacts root; gitignored)
  • package.json scripts: harness:run, harness:doctor
  • dependency: zod

Runtime artifacts are written under ./.harness/runs/* and MUST NOT be committed.

Preconditions

  • Run from (or inside) a Node.js repo that has a package.json.
  • If package.json is missing, stop and ask the user whether to create a Node project first.

Init Steps (deterministic)

  1. Locate repo root by searching upward for package.json.
  2. Copy the bundled templates from assets/template/ into the target repo root:
    • copy assets/template/harness/<repoRoot>/harness/
    • For harness.config.json: if the file already exists, merge (preserve user's existing keys, add only missing ones). If it does not exist, copy the template. Never silently overwrite user edits.
  3. Append /.harness/ to <repoRoot>/.gitignore (create file if missing).
  4. Update <repoRoot>/package.json (additive only):
    • Add scripts:
      • harness:run: node harness/run.mjs
      • harness:doctor: node harness/doctor.mjs
    • Add dependency zod (use dependencies unless the repo clearly wants devDependencies).
  5. Run npm install.
  6. Verify:
    • npm run harness:doctor
    • npm run harness:run -- --provider codex --task "hello harness"

Safety defaults

Read the full file on GitHub · 68 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. 4d ago First seen · 68 lines · 70 tokens per session scan A d0face01ef96

Subscribe to this mod's changes

harness-init-runner is a skill published in the GitHub repository rexleimo/aios (52 stars, last pushed today), licensed MIT. It adds 70 tokens to every session and 782 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.