Hook Development for Claude Code Plugins
anthropics/claude-plugins-official
Explains how to write Claude Code plugin hooks, both prompt-based checks and bash commands, for events such as PreToolUse, Stop and SessionStart.
Claude Code Hero Level 3: The Goblin Lair of Commands -- create a custom slash command in .claude/commands/
Install Level 3 The Goblin Lair
$ npx skills add kylesnowschwartz/claude-code-hero --skill level-3-the-goblin-lair -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install kylesnowschwartz/claude-code-hero level-3-the-goblin-lair --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/kylesnowschwartz/claude-code-hero.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/level-3-the-goblin-lair .claude/skills/level-3-the-goblin-lair && 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 "level-3-the-goblin-lair" agent skill from https://github.com/kylesnowschwartz/claude-code-hero/tree/main/skills/level-3-the-goblin-lair into .claude/skills/level-3-the-goblin-lair/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "level-3-the-goblin-lair", 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/kylesnowschwartz/claude-code-hero/tree/main/skills/level-3-the-goblin-lairType 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 kylesnowschwartz/claude-code-hero --skill level-3-the-goblin-lair -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install kylesnowschwartz/claude-code-hero level-3-the-goblin-lair --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/kylesnowschwartz/claude-code-hero.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/level-3-the-goblin-lair .agents/skills/level-3-the-goblin-lair && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "level-3-the-goblin-lair" agent skill from https://github.com/kylesnowschwartz/claude-code-hero/tree/main/skills/level-3-the-goblin-lair into .agents/skills/level-3-the-goblin-lair/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "level-3-the-goblin-lair", 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 kylesnowschwartz/claude-code-hero --skill level-3-the-goblin-lair -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install kylesnowschwartz/claude-code-hero level-3-the-goblin-lair --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/kylesnowschwartz/claude-code-hero.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/level-3-the-goblin-lair .cursor/skills/level-3-the-goblin-lair && 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 "level-3-the-goblin-lair" agent skill from https://github.com/kylesnowschwartz/claude-code-hero/tree/main/skills/level-3-the-goblin-lair into .cursor/skills/level-3-the-goblin-lair/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "level-3-the-goblin-lair", 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/kylesnowschwartz/claude-code-hero.git --path skills/level-3-the-goblin-lair--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 kylesnowschwartz/claude-code-hero --skill level-3-the-goblin-lair -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install kylesnowschwartz/claude-code-hero level-3-the-goblin-lair --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/kylesnowschwartz/claude-code-hero.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/level-3-the-goblin-lair .gemini/skills/level-3-the-goblin-lair && 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 "level-3-the-goblin-lair" agent skill from https://github.com/kylesnowschwartz/claude-code-hero/tree/main/skills/level-3-the-goblin-lair into .gemini/skills/level-3-the-goblin-lair/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "level-3-the-goblin-lair", 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 kylesnowschwartz/claude-code-hero level-3-the-goblin-lairInstalls 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 kylesnowschwartz/claude-code-hero --skill level-3-the-goblin-lair -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/kylesnowschwartz/claude-code-hero.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/level-3-the-goblin-lair .github/skills/level-3-the-goblin-lair && 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 "level-3-the-goblin-lair" agent skill from https://github.com/kylesnowschwartz/claude-code-hero/tree/main/skills/level-3-the-goblin-lair into .github/skills/level-3-the-goblin-lair/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "level-3-the-goblin-lair", 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 kylesnowschwartz/claude-code-hero --skill level-3-the-goblin-lair -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install kylesnowschwartz/claude-code-hero level-3-the-goblin-lair --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/kylesnowschwartz/claude-code-hero.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/level-3-the-goblin-lair .opencode/skills/level-3-the-goblin-lair && 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 "level-3-the-goblin-lair" agent skill from https://github.com/kylesnowschwartz/claude-code-hero/tree/main/skills/level-3-the-goblin-lair into .opencode/skills/level-3-the-goblin-lair/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "level-3-the-goblin-lair", 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
level-3-the-goblin-lair- GitHub stars
- 104
- Token cost
- ~1.2k tokens
- SKILL.md length
- 618 words
- Files
- 1
- Skills in repo
- 15
- Repo updated
- First seen
- Licence
- None found
At a glance
Claude Code Hero Level 3: The Goblin Lair of Commands -- create a custom slash command in .claude/commands/
- Tasks that involve Hooks and plugins
- SKILL.md covers Objective, Why This Matters, The Quest and Hints, plus 3 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Level 3 The Goblin Lair is an agent skill from kylesnowschwartz/claude-code-hero. Claude Code Hero Level 3: The Goblin Lair of Commands -- create a custom slash command in .claude/commands/
Its SKILL.md is about 1.2k 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 Hooks and plugins.
When your agent uses it
- Tasks that involve Hooks and plugins
Example prompts
- “/level-3-the-goblin-lair”
What it can do on your machine
Read from SKILL.md and the folder at commit 4abcc6d. 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
Links to these hosts (documentation or services it may open):
docs.anthropic.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
Level 3 The Goblin Lair loads about 1.2k tokens when it runs. Until then it costs about 33 tokens; SKILL.md has 618 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
Without a licence we can't republish the file, so here is its outline and opening line. It has 618 words (~1,172 tokens).
“Create a custom slash command at .claude/commands/hero-spell.md with valid YAML frontmatter and a useful prompt body.”
- name
- level-3-the-goblin-lair
Files
Just SKILL.md in skills/level-3-the-goblin-lair of kylesnowschwartz/claude-code-hero.
Open the folder on GitHubat commit 4abcc6d
Compare with similar skills
Level 3 The Goblin Lair 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 |
|---|---|---|---|---|---|---|
| Level 3 The Goblin Lair this skillkylesnowschwartz/claude-code-hero | 104 | — | ~1.2k | Automated safety check: Pass | None | |
| Hook Development for Claude Code Pluginsanthropics/claude-plugins-official | 38k | 10 repos | ~4.1k | Automated safety check: Notes | Apache-2.0 | |
| Claude Code Agent Developmentanthropics/claude-plugins-official | 38k | 7 repos | ~2.8k | Automated safety check: Pass | Apache-2.0 | |
| Claude Code Skill Developer Guidediet103/claude-code-infrastructure-showcase | 10k | 11 repos | ~3.5k | Automated safety check: Pass | MIT | |
| Plugin Settings Patternanthropics/claude-plugins-official | 38k | 7 repos | ~3k | Automated safety check: Pass | Apache-2.0 | |
| MCP Integration for Pluginsanthropics/claude-plugins-official | 38k | 11 repos | ~3.1k | Automated safety check: Pass | Apache-2.0 |
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- Official
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Claude Code Agent Development
anthropics/claude-plugins-official
Explains how to write agents for Claude Code plugins: the markdown file with YAML frontmatter, trigger descriptions, model and color settings, and system prompt design.
Claude Code Skill Developer Guide
diet103/claude-code-infrastructure-showcase
A guide to creating and managing Claude Code skills with auto-activation: skill-rules.json triggers, hooks, enforcement levels, YAML frontmatter and progressive disclosure.
- Official
Plugin Settings Pattern
anthropics/claude-plugins-official
Shows how Claude Code plugins keep per-project settings and state in .claude/plugin-name.local.md files with YAML frontmatter and a markdown body.
- Official
MCP Integration for Plugins
anthropics/claude-plugins-official
Explains how to bundle Model Context Protocol servers in a Claude Code plugin, covering config files, stdio, SSE, HTTP and WebSocket server types, and authentication.
- Official
Claude Code Command Development
anthropics/claude-plugins-official
Explains how to write Claude Code slash commands: Markdown files with YAML frontmatter, arguments, file references, bash context and interactive prompts.
More from kylesnowschwartz/claude-code-hero
All 15 skills in this repoLevel 1 The Map Room
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Claude Code Hero Level 1: The Map Room -- explore the project's .claude/ directory and document what lives there
Level 10 The Hall Of Watchers
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Claude Code Hero Level 10: The Hall of Watchers -- add a PreToolUse prompt hook with a multi-tool matcher
Level 11 The Oracle Well
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Claude Code Hero Level 11: The Oracle Well -- connect an MCP server and gain a new tool
Level 12 The Warband
kylesnowschwartz/claude-code-hero
Claude Code Hero Level 12: The Warband -- write a dynamic workflow that fans work out across agents
Level 2 The Tome
kylesnowschwartz/claude-code-hero
Claude Code Hero Level 2: The Tome of First Instructions -- create .claude/CLAUDE.md with real personal instructions
Level 4 The Wardens Keys
kylesnowschwartz/claude-code-hero
Claude Code Hero Level 4: The Warden's Keys -- configure permission rules in .claude/settings.json
Related
Categories
Questions about Level 3 The Goblin Lair
What does Level 3 The Goblin Lair do?
Claude Code Hero Level 3: The Goblin Lair of Commands -- create a custom slash command in .claude/commands/. Level 3 The Goblin Lair is an agent skill from kylesnowschwartz/claude-code-hero.
When should I use Level 3 The Goblin Lair?
Level 3 The Goblin Lair fits situations like: tasks that involve Hooks and plugins.
How do I install Level 3 The Goblin Lair in Claude Code?
Run `npx skills add kylesnowschwartz/claude-code-hero --skill level-3-the-goblin-lair -a claude-code`. Or copy the skill folder (skills/level-3-the-goblin-lair in kylesnowschwartz/claude-code-hero) into .claude/skills/level-3-the-goblin-lair in your project. Claude Code loads it when a task matches its description.
How do I install Level 3 The Goblin Lair in Codex?
Run `npx skills add kylesnowschwartz/claude-code-hero --skill level-3-the-goblin-lair -a codex`. Or copy the skill folder (skills/level-3-the-goblin-lair in kylesnowschwartz/claude-code-hero) into .agents/skills/level-3-the-goblin-lair in your project. Codex loads it when a task matches its description.
Can I use Level 3 The Goblin Lair 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 kylesnowschwartz/claude-code-hero --skill level-3-the-goblin-lair -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/level-3-the-goblin-lair, .gemini/skills/level-3-the-goblin-lair, .github/skills/level-3-the-goblin-lair and .opencode/skills/level-3-the-goblin-lair in your project.
What does Level 3 The Goblin Lair need to run?
SKILL.md names no scripts, command-line tools or credentials: Level 3 The Goblin Lair is instructions for the agent only.
Does Level 3 The Goblin Lair access the network?
SKILL.md names 1 domain. As links in the text: docs.anthropic.com. This is read from the text; nothing was executed.
Is Level 3 The Goblin Lair 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 Level 3 The Goblin Lair use?
No licence was found for Level 3 The Goblin Lair or its repository. Without one, default copyright applies: ask the author before reusing or redistributing it.
How many tokens does Level 3 The Goblin Lair use?
About 1.2k tokens (SKILL.md is roughly 4.7k 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 Level 3 The Goblin Lair?
Skills that share tags, products or a category with Level 3 The Goblin Lair: Hook Development for Claude Code Plugins (anthropics/claude-plugins-official, 38k stars), Claude Code Agent Development (anthropics/claude-plugins-official, 38k stars), Claude Code Skill Developer Guide (diet103/claude-code-infrastructure-showcase, 10k stars) and Plugin Settings Pattern (anthropics/claude-plugins-official, 38k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Level 3 The Goblin Lair?
kylesnowschwartz (a GitHub user) maintains it in kylesnowschwartz/claude-code-hero, which has 104 GitHub stars. The repository holds 15 skills in this directory. The repository was last updated on September 7, 2026.
Source: kylesnowschwartz/claude-code-hero on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.