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name: claude-code-mastery description: > Use when the user asks to "optimize CLAUDE.md", "create a new skill", "write a custom agent", "configure hooks", "manage context window", "set up MCP servers", "scaffold a skill package", "analyze token budget", "create subagents", "configure permissions", "set up worktrees", or "integrate Claude Code with editors". Covers Claude Code CLI mastery, skill authoring, context engineering, hooks automation, subagent creation, and development workflow optimization. license: MIT metadata: version: 1.1.0 author: borghei category: engineering domain: development-tools updated: 2026-06-17 tags: [claude-code, skill-authoring, subagents, hooks]

Claude Code Mastery

Expert skill for Claude Code CLI -- CLAUDE.md optimization, skill authoring, subagent creation, hooks automation, and context engineering.

Keywords: claude-code, claude-cli, CLAUDE.md, skill-authoring, subagents, hooks, context-window, token-budget, MCP-servers, worktrees, permission-modes, prompt-engineering, context-engineering, slash-commands

Core Capabilities

• CLAUDE.md optimization — audit, restructure, compress, and hierarchize config files for token efficiency.
• Skill authoring — scaffold and write discoverable skill packages with correct layout and frontmatter.
• Subagent creation — write .claude/agents/<name>.md files with a tools allowlist and a Markdown-body system prompt.
• Hooks automation — wire PreToolUse/PostToolUse/Stop lifecycle scripts via .claude/settings.json.
• Context engineering — measure and manage the context-window token budget across a codebase.

When to Use

• Authoring, structuring, or optimizing a CLAUDE.md file for any project.
• Scaffolding a new skill package or creating a Claude Code subagent.
• Configuring hooks for automated quality, security, or workflow steps.
• Auditing and reducing context-window consumption.

Clarify First

Before scaffolding or optimizing, confirm these inputs. If any is unknown or vague, ASK — do not assume:

• Which task — scaffold a new skill, optimize a CLAUDE.md, create a subagent, or analyze context budget (selects skill_scaffolder.py vs claudemd_optimizer.py vs context_analyzer.py)
• Target identity — for a new skill: its name, domain, and one-line description; for optimization: the file or project path (the inputs the scripts require)
• Token budget — the target ceiling (sets --token-limit and what counts as over-budget)

Stop rule: ask only the 2-3 that most change the output. If the user says "just draft it," proceed and list your assumptions at the top of the artifact.

Quick Start

# Scaffold a new skill package
python scripts/skill_scaffolder.py my-new-skill --domain engineering --description "Brief description"

# Analyze and optimize an existing CLAUDE.md
python scripts/claudemd_optimizer.py path/to/CLAUDE.md

# Estimate context window usage across a project
python scripts/context_analyzer.py /path/to/project

# All tools support JSON output
python scripts/claudemd_optimizer.py CLAUDE.md --json

Tools

Tool	Purpose	Command
skill_scaffolder.py	Scaffold a new skill package with correct structure + frontmatter	python scripts/skill_scaffolder.py my-skill -d engineering --description "Does X"
claudemd_optimizer.py	Score a CLAUDE.md for structure, tokens, and redundancy with recommendations	python scripts/claudemd_optimizer.py CLAUDE.md --token-limit 4000
context_analyzer.py	Estimate context-window consumption by file category with a budget breakdown	python scripts/context_analyzer.py /path/to/project --max-depth 4

All tools support --json. See references/tool-reference.md for full parameter tables and output formats.

References

Load the reference that matches the task — keep this file lean and pull detail on demand:

• references/workflows.md — the five numbered playbooks: optimize a CLAUDE.md, author a skill, create a subagent, configure hooks, and manage the context budget. Read when executing any of those tasks step-by-step.
• references/quick-reference.md — slash commands, permission modes, CLAUDE.md loading order, MCP servers, the troubleshooting table, and success criteria. Read for at-a-glance lookups or when debugging configuration.
• references/tool-reference.md — full parameter tables and output formats for the three Python tools. Read when scripting the tools or interpreting their JSON output.
• references/skill-authoring-guide.md — comprehensive reference for writing effective skills, from YAML frontmatter to structure. Read when authoring a skill in depth.
• references/subagent-patterns.md — guide to creating and using subagents for parallel work and scoped tasks. Read when designing a subagent.
• references/hooks-cookbook.md — practical hook recipes for code quality, security enforcement, and workflow automation. Read when building hooks.

Templates: assets/skill-template.md, assets/agent-template.md

Scope & Limitations

This skill covers:

• Authoring, structuring, and optimizing CLAUDE.md files for any project
• Scaffolding new skill packages with correct directory layout and frontmatter
• Creating and configuring Claude Code subagents with scoped tool access
• Analyzing and managing context window token budgets across a codebase

This skill does NOT cover:

• Writing application source code or implementing business logic (see senior-fullstack, senior-backend)
• MCP server development or custom transport protocols (see mcp-server-builder)
• Advanced prompt engineering techniques for LLM applications (see senior-prompt-engineer)
• CI/CD pipeline configuration or deployment automation (see senior-devops, ci-cd-pipeline-builder)

Integration Points

Skill	Integration	Data Flow
senior-architect	Architecture decisions inform CLAUDE.md structure sections	Architecture diagrams and patterns feed into the Architecture Overview section of CLAUDE.md
code-reviewer	Subagent creation for automated code review	Claude Code Mastery creates the agent .md file; Code Reviewer provides the review logic
senior-prompt-engineer	Prompt optimization for skill descriptions and agent instructions	Prompt engineering techniques improve YAML frontmatter trigger phrases and agent system prompts (the agent file body)
doc-drift-detector	Detects when CLAUDE.md drifts out of sync with the codebase	Context Analyzer output feeds drift detection; drift findings trigger CLAUDE.md optimization
context-engine	Advanced context management strategies	Context Analyzer provides token budgets; Context Engine applies compression and prioritization
senior-secops	Security hooks and permission mode configuration	SecOps policies define which tools to deny; Claude Code Mastery configures the permission allowlists