Ponytail
DavidObando/gsharp
Forces the laziest solution that actually works, simplest, shortest, most minimal.
“Build feature work with high overbuilding risk. Use for new behavior, product slices, or integrations where repository reuse, strict scope, and an explicit stop condition matter.”
Install Lean Build
$ npx skills add JuliusBrussee/caveman --skill lean-build -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install JuliusBrussee/caveman lean-build --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/JuliusBrussee/caveman.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/lean-build .claude/skills/lean-build && 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 "lean-build" agent skill from https://github.com/JuliusBrussee/caveman/tree/main/skills/lean-build into .claude/skills/lean-build/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "lean-build", 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/JuliusBrussee/caveman/tree/main/skills/lean-buildType 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 JuliusBrussee/caveman --skill lean-build -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install JuliusBrussee/caveman lean-build --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/JuliusBrussee/caveman.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/lean-build .agents/skills/lean-build && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "lean-build" agent skill from https://github.com/JuliusBrussee/caveman/tree/main/skills/lean-build into .agents/skills/lean-build/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "lean-build", 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 JuliusBrussee/caveman --skill lean-build -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install JuliusBrussee/caveman lean-build --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/JuliusBrussee/caveman.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/lean-build .cursor/skills/lean-build && 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 "lean-build" agent skill from https://github.com/JuliusBrussee/caveman/tree/main/skills/lean-build into .cursor/skills/lean-build/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "lean-build", 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/JuliusBrussee/caveman.git --path skills/lean-build--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 JuliusBrussee/caveman --skill lean-build -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install JuliusBrussee/caveman lean-build --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/JuliusBrussee/caveman.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/lean-build .gemini/skills/lean-build && 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 "lean-build" agent skill from https://github.com/JuliusBrussee/caveman/tree/main/skills/lean-build into .gemini/skills/lean-build/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "lean-build", 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 JuliusBrussee/caveman lean-buildInstalls 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 JuliusBrussee/caveman --skill lean-build -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/JuliusBrussee/caveman.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/lean-build .github/skills/lean-build && 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 "lean-build" agent skill from https://github.com/JuliusBrussee/caveman/tree/main/skills/lean-build into .github/skills/lean-build/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "lean-build", 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 JuliusBrussee/caveman --skill lean-build -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install JuliusBrussee/caveman lean-build --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/JuliusBrussee/caveman.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/lean-build .opencode/skills/lean-build && 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 "lean-build" agent skill from https://github.com/JuliusBrussee/caveman/tree/main/skills/lean-build into .opencode/skills/lean-build/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "lean-build", 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
lean-build- GitHub stars
- 111k
- Used in
- 1 other repo
- Token cost
- ~273 tokens
- SKILL.md length
- 113 words
- Files
- 2
- Skills in repo
- 18
- Repo updated
- First seen
- Licence
- Apache-2.0
At a glance
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
About this skill
Lean Build is a skill in JuliusBrussee/caveman (111k stars). Its SKILL.md is about 273 tokens, with 1 other file in the folder, and copies of it appear in 1 other owners' repositories. Licence: Apache-2.0.
What it can do on your machine
Read from SKILL.md and the folder at commit 2e08b91. 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
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
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
Lean Build loads about 273 tokens when it runs. Until then it costs about 47 tokens; SKILL.md has 113 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
The full file from JuliusBrussee/caveman at commit 2e08b91, republished under its Apache-2.0 licence (© JuliusBrussee). 113 words, ~273 tokens.
Download SKILL.mdSave it as
.claude/skills/lean-build/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- lean-build
- description
- Build feature work with high overbuilding risk. Use for new behavior, product slices, or integrations where repository reuse, strict scope, and an explicit stop condition matter.
Lean build
Native Core's architecture-first simplicity remains mandatory. Turn feature into complete narrow outcome fitting system.
- Derive observable acceptance and explicit non-goals from request and repository.
- Trace entry point through layers owning invariants.
- Deliver coherent end-to-end path across responsible layers; never force work into one file, direct expression, or local patch.
- Reuse fitting seam. Refactor when patching duplicates behavior, weakens ownership, or hides root cause.
- Omit modes, providers, config, extensibility, and polish unless acceptance needs them.
- Add surface, dependency, service, config, or migration only for lifecycle design or acceptance; state material tradeoff.
- Keep work runnable; preserve Core safety.
Exercise path. Run focused proof. Stop when acceptance passes. Report only material omissions and trigger.
© JuliusBrussee, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 1 other file in skills/lean-build of JuliusBrussee/caveman.
- SKILL.md
- agents/openai.yaml
Open the folder on GitHubat commit 2e08b91
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 JuliusBrussee/caveman, which our catalogue first saw on October 7, 2026.
Compare with similar skills
Lean Build 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 |
|---|---|---|---|---|---|---|
| Lean Build this skillJuliusBrussee/caveman | 111k | 1 repos | ~273 | Automated safety check: Pass | Apache-2.0 | |
| PonytailDavidObando/gsharp | 564 | 8 repos | ~1.7k | Automated safety check: Pass | MIT | |
| Ponytail Reviewkortix-ai/suna | 20k | 4 repos | ~593 | Automated safety check: Pass | Custom licence | |
| Ponytail Lazy Developer ModeDietrichGebert/ponytail | 159k | — | ~873 | Automated safety check: Pass | MIT | |
| Code Simplification for ego-litecitrolabs/ego-lite | 17k | — | ~1.2k | Automated safety check: Pass | MIT | |
| Refactor Pass for Simplicitystar-history/star-history | 9.6k | 1 repos | ~168 | Automated safety check: Pass | MIT |
Similar skills
Ponytail Review
kortix-ai/suna
Code review focused exclusively on over-engineering. An agent skill from kortix-ai/suna.
Ponytail Lazy Developer Mode
DietrichGebert/ponytail
Makes the agent pick the laziest solution that works: skip unneeded work, reuse what exists, prefer the standard library and platform features, and keep diffs small.
Code Simplification for ego-lite
citrolabs/ego-lite
Finds and implements evidence-backed simplifications in the ego-lite repository, such as dead code, duplicated state and speculative abstractions, without hiding behavior changes.
Refactor Pass for Simplicity
star-history/star-history
Perform a refactor pass focused on simplicity after recent changes. Use when the user asks for a refactor/cleanup pass, simplification, or dead-code removal…
RTK Rust Code Simplifier
rtk-ai/rtk
Reviews RTK's Rust code for over-engineering and verbose patterns, applying idioms like iterator chains and early returns while protecting a specific list of constraints from being simplified away.
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Related
Categories
Questions about Lean Build
How do I install Lean Build in Claude Code?
Run `npx skills add JuliusBrussee/caveman --skill lean-build -a claude-code`. Or copy the skill folder (skills/lean-build in JuliusBrussee/caveman) into .claude/skills/lean-build in your project. Claude Code loads it when a task matches its description.
How do I install Lean Build in Codex?
Run `npx skills add JuliusBrussee/caveman --skill lean-build -a codex`. Or copy the skill folder (skills/lean-build in JuliusBrussee/caveman) into .agents/skills/lean-build in your project. Codex loads it when a task matches its description.
Can I use Lean Build 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 JuliusBrussee/caveman --skill lean-build -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/lean-build, .gemini/skills/lean-build, .github/skills/lean-build and .opencode/skills/lean-build in your project.
What does Lean Build need to run?
SKILL.md names no scripts, command-line tools or credentials: Lean Build is instructions for the agent only.
Does Lean Build access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Lean Build 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 Lean Build use?
Lean Build is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Lean Build use?
About 273 tokens (SKILL.md is roughly 1.1k 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 Lean Build?
Skills that share tags, products or a category with Lean Build: Ponytail (DavidObando/gsharp, 564 stars), Ponytail Review (kortix-ai/suna, 20k stars), Ponytail Lazy Developer Mode (DietrichGebert/ponytail, 159k stars) and Code Simplification for ego-lite (citrolabs/ego-lite, 17k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Lean Build?
JuliusBrussee (a GitHub user) maintains it in JuliusBrussee/caveman, which has 110,632 GitHub stars. The repository holds 18 skills in this directory. The repository was last updated on October 8, 2026.
Source: JuliusBrussee/caveman on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.