harness-cli is on PATH inside this worktree. It is your control surface for the whole harness: the agentboard (the only sanctioned way to talk to other agents), worker-session lifecycle (session new -d / session kill), one-shot submit + logs / watch, worktree file transfer (file push / file pull), and operator notifications (notify). All required credentials are passed via HARNESS_* environment variables (already set by the runner) — never pass them as flags.
Harness CLI is a community-contributed Claude Code skill in the general-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/harness-cli/ and loads when your prompt matches the skill's trigger.
When to invoke it: Use when working with other agents or the harness from inside a runner-spawned task — messaging peers on the agentboard, spawning / driving / killing worker agent sessions, delegating one-shot tasks, moving files in or out of a task's worktree, notifying the human operator, or discovering live agents and topics. Also defines the agentboard conventions (handshake, reply topics, trust model).
The Harness CLI Claude Code skill is built for Claude Code users and developers across all disciplines looking for general-purpose AI assistance. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 196,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).
mkdir -p ~/.claude/skills/harness-cli curl -L https://claudskills.com/skills/harness-cli/SKILL.md \ -o ~/.claude/skills/harness-cli/SKILL.md
Or just download SKILL.md directly and drop it into ~/.claude/skills/harness-cli/. Claude Code auto-discovers it on next session.
Skills live at ~/.claude/skills/harness-cli/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\harness-cli\SKILL.md on Windows. See the full install guide for step-by-step instructions.
Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →
The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.
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SKILL.md from the source repository to ~/.claude/skills/harness-cli/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Harness CLI is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the General category. Learn more at /learn/what-is-a-claude-skill/.If you reference this skill in a blog post, paper, or documentation, you can cite it as:
@misc{harness-cli-2026,
author = {on-keyday},
title = {Harness CLI [Claude Code skill]},
year = {2026},
publisher = {ClaudSkills},
url = {https://claudskills.com/skills/harness-cli/}
}Grade A · scanned 2026-09-28 — free static scan against the OWASP Agentic Skills Top 10.
No risk patterns were found in any of the ten OWASP-aligned categories. How grading works ›
Browse all General skills in the ClaudSkills registry, or explore these other picks from the same category:
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SKILL.md files, not affiliated with, endorsed by, or sponsored by Anthropic.