Claude Ecosystem

Claude Ecosystem

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

Module Selection

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Quick Reference

Extension Types

Model Selection (Agents)

CLAUDE.md Token Budget

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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

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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 Find redundancy, outdated info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

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Anti-Patterns

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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

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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

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Related Skills

IMPORTANT: When creating/​editing prompts, use prompt-architect skill.

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

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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