Harness Agent Team Designer
revfactory/harness
Designs a project-specific agent harness: defines specialist agents, writes the skills they follow, picks an execution mode and model for each, and keeps the setup maintained.
Guides repo-local skill creation and updates. An agent skill from ccusage/ccusage.
Install Skill Creator
$ npx skills add ccusage/ccusage --skill skill-creator -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install ccusage/ccusage skill-creator --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/ccusage/ccusage.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/skill-creator .claude/skills/skill-creator && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "skill-creator" agent skill from https://github.com/ccusage/ccusage/tree/main/.agents/skills/skill-creator into .claude/skills/skill-creator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skill-creator", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/ccusage/ccusage/tree/main/.agents/skills/skill-creatorType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add ccusage/ccusage --skill skill-creator -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install ccusage/ccusage skill-creator --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ccusage/ccusage.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/skill-creator .agents/skills/skill-creator && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "skill-creator" agent skill from https://github.com/ccusage/ccusage/tree/main/.agents/skills/skill-creator into .agents/skills/skill-creator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skill-creator", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add ccusage/ccusage --skill skill-creator -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install ccusage/ccusage skill-creator --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ccusage/ccusage.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/skill-creator .cursor/skills/skill-creator && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "skill-creator" agent skill from https://github.com/ccusage/ccusage/tree/main/.agents/skills/skill-creator into .cursor/skills/skill-creator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skill-creator", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/ccusage/ccusage.git --path .agents/skills/skill-creator--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add ccusage/ccusage --skill skill-creator -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install ccusage/ccusage skill-creator --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ccusage/ccusage.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/skill-creator .gemini/skills/skill-creator && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "skill-creator" agent skill from https://github.com/ccusage/ccusage/tree/main/.agents/skills/skill-creator into .gemini/skills/skill-creator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skill-creator", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install ccusage/ccusage skill-creatorInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add ccusage/ccusage --skill skill-creator -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/ccusage/ccusage.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/skill-creator .github/skills/skill-creator && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "skill-creator" agent skill from https://github.com/ccusage/ccusage/tree/main/.agents/skills/skill-creator into .github/skills/skill-creator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skill-creator", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add ccusage/ccusage --skill skill-creator -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install ccusage/ccusage skill-creator --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ccusage/ccusage.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/skill-creator .opencode/skills/skill-creator && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "skill-creator" agent skill from https://github.com/ccusage/ccusage/tree/main/.agents/skills/skill-creator into .opencode/skills/skill-creator/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skill-creator", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
skill-creator- GitHub stars
- 19k
- Token cost
- ~1.1k tokens
- SKILL.md length
- 563 words
- Files
- 1
- Skills in repo
- 17
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Guides repo-local skill creation and updates. An agent skill from ccusage/ccusage.
- Works in 5 steps: Write .agents/skills//SKILL.md with… → Move conditional detail — long… → Put deterministic repeated operations in… → …
- Editing .agents/skills
- SKILL.md covers Adding or Editing a Skill, Frontmatter, Body and Line Budgets
- Calls just
What it does
Skill Creator is an agent skill from ccusage/ccusage. Guides repo-local skill creation and updates. Use when adding or editing .agents/skills, root AGENTS.md routing, SKILL.md frontmatter, description trigger quality, references layout, skill scripts, or skill file line budgets.
Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Agent Workflows, covering Skill authoring and Agent instruction files.
When your agent uses it
- Editing .agents/skills
- Root AGENTS.md routing
- SKILL.md frontmatter
- Description trigger quality
Example prompts
- “Use the skill-creator skill to guide repo-local skill creation and updates. An agent skill from ccusage/ccusage”
- “/skill-creator”
Workflow steps
5 steps, taken from the first numbered list in SKILL.md.
- Write .agents/skills//SKILL.md with frontmatter plus concise Markdown.
- Move conditional detail — long checklists, APIs, examples — into references/*.md and link each
- Put deterministic repeated operations in scripts/ instead of prose.
- Add the skill to the Skill Routing list in the root AGENTS.md so agents discover it.
- Run just fmt after edits.
What it can do on your machine
Read from SKILL.md and the folder at commit d2fd844. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
just
From the folder's file list and the shell code blocks in SKILL.md.
Network
Links to these hosts (documentation or services it may open):
simonwillison.netclaude.com
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
Skill Creator loads about 1.1k tokens when it runs. Until then it costs about 60 tokens; SKILL.md has 563 words of instructions outside code blocks.
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
Auto-check passed
The automated check found no risky patterns in SKILL.md.
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
Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 563 words (~1,054 tokens).
“.agents/skills/ is the source of truth for repo-local skills. .claude/skills is generated by agent-skills-nix through the Nix dev-shell hook and is gitignored — never edit or commit it.”
- name
- skill-creator
Files
Just SKILL.md in .agents/skills/skill-creator of ccusage/ccusage.
Open the folder on GitHubat commit d2fd844
Compare with similar skills
Skill Creator next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Skill Creator this skillccusage/ccusage | 19k | — | ~1.1k | Automated safety check: Pass | Custom licence | |
| Harness Agent Team Designerrevfactory/harness | 9.1k | — | ~4.5k | Automated safety check: Pass | Apache-2.0 | |
| Harness Evolution Feedback Looprevfactory/harness | 9.1k | — | ~855 | Automated safety check: Pass | Apache-2.0 | |
| ShellLM Skill Authorlaude-institute/headlong | 1.2k | — | ~1.3k | Automated safety check: Pass | Apache-2.0 | |
| Skill CreatorGentleman-Programming/gentle-ai | 7.6k | — | ~998 | Automated safety check: Pass | Apache-2.0 | |
| Fix Prompt Evaluation Diagnosticsmicrosoft/vscode-chat-customizations-evaluation | 141 | — | ~506 | Automated safety check: Pass | Custom licence |
Similar skills
Harness Evolution Feedback Loop
revfactory/harness
Collects feedback on how an agent harness performed, generalizes it, and updates the harness agents, skills and orchestrator along with a change-history table.
ShellLM Skill Author
laude-institute/headlong
Scaffolds new ShellLM skills with the right frontmatter, directory layout and agent-facing writing style, so an agent can extend its own capabilities.
Skill Creator
Gentleman-Programming/gentle-ai
Guides writing a new agent skill: when one is warranted, the required folder layout and frontmatter, section order and size limits, with a bundled style guide.
- Official
Fix Prompt Evaluation Diagnostics
microsoft/vscode-chat-customizations-evaluation
Applies the fixes suggested by the Chat Customizations Evaluations extension to a prompt, agent, skill or instruction file, changing only what each diagnostic requires.
Skill Creator
Gentleman-Programming/Gentleman-Skills
Creates new AI agent skills following the Agent Skills spec.
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Related
Categories
Questions about Skill Creator
What does Skill Creator do?
Guides repo-local skill creation and updates. An agent skill from ccusage/ccusage. Skill Creator is an agent skill from ccusage/ccusage. Guides repo-local skill creation and updates.
When should I use Skill Creator?
Skill Creator fits situations like: editing .agents/skills; root AGENTS.md routing; SKILL.md frontmatter; description trigger quality.
How do I install Skill Creator in Claude Code?
Run `npx skills add ccusage/ccusage --skill skill-creator -a claude-code`. Or copy the skill folder (.agents/skills/skill-creator in ccusage/ccusage) into .claude/skills/skill-creator in your project. Claude Code loads it when a task matches its description.
How do I install Skill Creator in Codex?
Run `npx skills add ccusage/ccusage --skill skill-creator -a codex`. Or copy the skill folder (.agents/skills/skill-creator in ccusage/ccusage) into .agents/skills/skill-creator in your project. Codex loads it when a task matches its description.
Can I use Skill Creator in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add ccusage/ccusage --skill skill-creator -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/skill-creator, .gemini/skills/skill-creator, .github/skills/skill-creator and .opencode/skills/skill-creator in your project.
What does Skill Creator need to run?
Going by SKILL.md and its folder, Skill Creator needs the command-line tools its instructions call (just).
Does Skill Creator access the network?
SKILL.md names 2 domains. As links in the text: simonwillison.net and claude.com. This is read from the text; nothing was executed.
Is Skill Creator safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Skill Creator use?
Skill Creator has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.
How many tokens does Skill Creator use?
About 1.1k tokens (SKILL.md is roughly 4.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Skill Creator?
Skills that share tags, products or a category with Skill Creator: Harness Agent Team Designer (revfactory/harness, 9.1k stars), Harness Evolution Feedback Loop (revfactory/harness, 9.1k stars), ShellLM Skill Author (laude-institute/headlong, 1.2k stars) and Skill Creator (Gentleman-Programming/gentle-ai, 7.6k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Skill Creator?
ccusage (a GitHub organization) maintains it in ccusage/ccusage, which has 18,901 GitHub stars. The repository holds 17 skills in this directory. The repository was last updated on October 7, 2026.
Source: ccusage/ccusage on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.