Claude Ecosystem

Comprehensive guide for Claude Code CLI tool, extensibility (agents/skills/output styles), and CLAUDE.md architecture.

Module Selection

references/getting-started.md

references/configuration.md

references/slash-commands.md

references/mcp-integration.md

references/hooks-and-plugins.md

references/agent-development.md

references/skill-development.md

references/skill-development.md

references/initialization-workflow.md

references/optimization-patterns.md

references/enterprise-features.md

references/cicd-integration.md

references/troubleshooting.md

Quick Reference

Extension Types

.claude/agents/

.claude/skills/{name}/

/output-style

.claude/output-styles/

Model Selection (Agents)

haiku

sonnet

opus

CLAUDE.md Token Budget

Extensibility Principles

Core Truths

Decision Heuristics

Activation Keywords

The description field is your activation gate. Include:

1. Task verbs: create, build, debug, fix, deploy
2. Problem descriptions: slow, broken, failing
3. Artifact types: component, API, database
4. Casual synonyms: "make it faster" → optimize

Common Workflows

Create Agent

---
name: agent-name
description: "Use when [use case]. PROACTIVELY for [triggers].\n\nExamples:\n<example>\nContext: [situation]\nuser: [request]\nassistant: [response]\n</example>"
tools: Grep, Glob, Read, Bash
model: haiku
---

# Agent Name

Mission statement.

## Strategy
[Approach]

## Does NOT Do
- [boundary] (use X instead)

Create Skill

---
name: skill-name
description: "[Core purpose]. [Technologies]. Capabilities: [list].
  Actions: [verbs]. Keywords: [triggers]. Use when: [scenarios]."
allowed-tools: Read, Grep, Glob
---

# Skill Name

## Patterns

### [Pattern Name]
**When you see:** [Observable trigger]
**This indicates:** [Expert insight]
**Therefore:** [Action]
**Watch out:** [Pitfall]

Initialize CLAUDE.md

1. Analyze codebase (language, framework, structure)
2. Extract code style, commands, patterns
3. Generate with template, customize
4. Validate commands, check token count
5. Target <400 lines, prefer <250

Detailed:

references/initialization-workflow.md

Optimize CLAUDE.md

1. Evaluate token efficiency
2. Find redundancy, outdated info
3. Apply token reduction techniques
4. Target 40%+ reduction
5. Verify critical info retained

Detailed:

references/optimization-patterns.md

Anti-Patterns

Quality Signals

Good Signs

• Frontmatter reads like "when to use" guide
• First 10 lines provide actionable guidance
• Expert would nod "yes, that's how I think"
• Explicit constraints on what it does NOT handle

Warning Signs

• 50% reference tables or field definitions

• No mention of "when NOT to use"
• Generic language for any domain
• Body exceeds 600 lines

References

CLI Tool

• references/getting-started.md

  - Installation, setup, auth

• references/slash-commands.md

  - Complete command catalog

• references/mcp-integration.md

  - MCP server configuration

• references/hooks-and-plugins.md

  - Hook types, plugin structure

• references/configuration.md

  - Settings hierarchy

• references/enterprise-features.md

  - IAM, SSO, sandboxing

• references/cicd-integration.md

  - GitHub Actions, GitLab CI

• references/ide-integration.md

  - VS Code, JetBrains

• references/advanced-features.md

  - Extended thinking, caching

• references/troubleshooting.md

  - Common issues

• references/api-reference.md

  - Admin, Messages, Skills APIs

• references/best-practices.md

  - Project organization, security

• references/agent-skills.md

  - Creating skills via CLI

Extensibility

• references/agent-development.md

  - Full YAML structure, system prompts

• references/skill-development.md

  - Structure, triggers, hooks

CLAUDE.md

• references/initialization-workflow.md

  - Creating new CLAUDE.md

• references/optimization-patterns.md

  - Token reduction techniques

• references/integration-strategies.md

  - Global config, MCP tools

• references/output-templates.md

  - Standard output formats

Related Skills

IMPORTANT: When creating/editing prompts, use

prompt-architect

Skill("prompt-architect") → Create/enhance skill/agent prompt content

Documentation:

• llms.txt: https://context7.com/websites/claude_en_claude-code/llms.txt?tokens=10000
• Main docs: https://docs.claude.com/en/docs/claude-code/
• GitHub: https://github.com/anthropics/claude-code