docs/SKILL-DEVELOPMENT-GUIDE.md
A comprehensive guide to creating effective skills for Everything Claude Code (ECC).
Skills are knowledge modules that Claude Code loads based on context. They provide:
Unlike agents (specialized subassistants) or commands (user-triggered actions), skills are passive knowledge that Claude Code references when relevant.
Skills activate when:
| Component | Purpose | Activation |
|---|---|---|
| Skill | Knowledge repository | Context-based (automatic) |
| Agent | Task executor | Explicit delegation |
| Command | User action | User-invoked (/command) |
| Hook | Automation | Event-triggered |
| Rule | Always-on guidelines | Always active |
skills/
└── your-skill-name/
├── SKILL.md # Required: Main skill definition
├── examples/ # Optional: Code examples
│ ├── basic.ts
│ └── advanced.ts
└── references/ # Optional: External references
└── links.md
---
name: skill-name
description: Brief description shown in skill list and used for auto-activation
origin: ECC
---
# Skill Title
Brief overview of what this skill covers.
## When to Activate
Describe scenarios where Claude should use this skill.
## Core Concepts
Main patterns and guidelines.
## Code Examples
\`\`\`typescript
// Practical, tested examples
\`\`\`
## Anti-Patterns
Show what NOT to do with concrete examples.
## Best Practices
- Actionable guidelines
- Do's and don'ts
## Related Skills
Link to complementary skills.
| Field | Required | Description |
|---|---|---|
name | Yes | Lowercase, hyphenated identifier (e.g., react-patterns) |
description | Yes | One-line description for skill list and auto-activation |
origin | No | Source identifier (e.g., ECC, community, project name) |
tags | No | Array of tags for categorization |
version | No | Skill version for tracking updates |
Good skills are focused and actionable:
| PASS: Good Focus | FAIL: Too Broad |
|---|---|
react-hook-patterns | react |
postgresql-indexing | databases |
pytest-fixtures | python-testing |
nextjs-app-router | nextjs |
mkdir -p skills/your-skill-name
Here's a minimal template:
---
name: your-skill-name
description: Brief description of when to use this skill
---
# Your Skill Title
Brief overview (1-2 sentences).
## When to Activate
- Scenario 1
- Scenario 2
- Scenario 3
## Core Concepts
### Concept 1
Explanation with examples.
### Concept 2
Another pattern with code.
## Code Examples
\`\`\`typescript
// Practical example
\`\`\`
## Best Practices
- Do this
- Avoid that
## Related Skills
- `related-skill-1`
- `related-skill-2`
Write content that Claude can immediately use:
Focus on idiomatic code, naming conventions, and language-specific patterns.
Examples: python-patterns, golang-patterns, typescript-standards
---
name: python-patterns
description: Python idioms, best practices, and patterns for clean, idiomatic code.
---
# Python Patterns
## When to Activate
- Writing Python code
- Refactoring Python modules
- Python code review
## Core Concepts
### Context Managers
\`\`\`python
# Always use context managers for resources
with open('file.txt') as f:
content = f.read()
\`\`\`
Focus on framework-specific conventions, common patterns, and anti-patterns.
Examples: django-patterns, nextjs-patterns, springboot-patterns
---
name: django-patterns
description: Django best practices for models, views, URLs, and templates.
---
# Django Patterns
## When to Activate
- Building Django applications
- Creating models and views
- Django URL configuration
Define step-by-step processes for common development tasks.
Examples: tdd-workflow, code-review-workflow, deployment-checklist
---
name: code-review-workflow
description: Systematic code review process for quality and security.
---
# Code Review Workflow
## Steps
1. **Understand Context** - Read PR description and linked issues
2. **Check Tests** - Verify test coverage and quality
3. **Review Logic** - Analyze implementation for correctness
4. **Check Security** - Look for vulnerabilities
5. **Verify Style** - Ensure code follows conventions
Specialized knowledge for specific domains (security, performance, etc.).
Examples: security-review, performance-optimization, api-design
---
name: api-design
description: REST and GraphQL API design patterns, versioning, and best practices.
---
# API Design Patterns
## RESTful Conventions
| Method | Endpoint | Purpose |
|--------|----------|---------|
| GET | /resources | List all |
| GET | /resources/:id | Get one |
| POST | /resources | Create |
Guidance for using specific tools, libraries, or services.
Examples: supabase-patterns, docker-patterns, mcp-server-patterns
This section is critical for auto-activation. Be specific:
## When to Activate
- Creating new React components
- Refactoring existing components
- Debugging React state issues
- Reviewing React code for best practices
Bad:
## Error Handling
Always handle errors properly in async functions.
Good:
## Error Handling
\`\`\`typescript
async function fetchData(url: string) {
try {
const response = await fetch(url)
if (!response.ok) {
throw new Error(\`HTTP \${response.status}: \${response.statusText}\`)
}
return await response.json()
} catch (error) {
console.error('Fetch failed:', error)
throw new Error('Failed to fetch data')
}
}
\`\`\`
### Key Points
- Check \`response.ok\` before parsing
- Log errors for debugging
- Re-throw with user-friendly message
Show what NOT to do:
## Anti-Patterns
### FAIL: Direct State Mutation
\`\`\`typescript
// NEVER do this
user.name = 'New Name'
items.push(newItem)
\`\`\`
### PASS: Immutable Updates
\`\`\`typescript
// ALWAYS do this
const updatedUser = { ...user, name: 'New Name' }
const updatedItems = [...items, newItem]
\`\`\`
Checklists are actionable and easy to follow:
## Pre-Deployment Checklist
- [ ] All tests passing
- [ ] No console.log in production code
- [ ] Environment variables documented
- [ ] Secrets not hardcoded
- [ ] Error handling complete
- [ ] Input validation in place
For complex decisions:
## Choosing the Right Approach
\`\`\`
Need to fetch data?
├── Single request → use fetch directly
├── Multiple independent → Promise.all()
├── Multiple dependent → await sequentially
└── With caching → use SWR or React Query
\`\`\`
| Practice | Example |
|---|---|
| Be specific | "Use `useCallback` for event handlers passed to child components" |
| Show examples | Include copy-pasteable code |
| Explain WHY | "Immutability prevents unexpected side effects in React state" |
| Link related skills | "See also: `react-performance`" |
| Keep focused | One skill = one domain/concept |
| Use sections | Clear headers for easy scanning |
| Practice | Why It's Bad |
|---|---|
| Be vague | "Write good code" - not actionable |
| Long prose | Hard to parse, better as code |
| Cover too much | "Python, Django, and Flask patterns" - too broad |
| Skip examples | Theory without practice is less useful |
| Ignore anti-patterns | Learning what NOT to do is valuable |
## and ### hierarchy- for unordered, 1. for ordered---
name: language-standards
description: Coding standards and best practices for [language].
---
# [Language] Coding Standards
## When to Activate
- Writing [language] code
- Code review
- Setting up linting
## Naming Conventions
| Element | Convention | Example |
|---------|------------|---------|
| Variables | camelCase | userName |
| Constants | SCREAMING_SNAKE | MAX_RETRY |
| Functions | camelCase | fetchUser |
| Classes | PascalCase | UserService |
## Code Examples
[Include practical examples]
## Linting Setup
[Include configuration]
## Related Skills
- `language-testing`
- `language-security`
---
name: task-workflow
description: Step-by-step workflow for [task].
---
# [Task] Workflow
## When to Activate
- [Trigger 1]
- [Trigger 2]
## Prerequisites
- [Requirement 1]
- [Requirement 2]
## Steps
### Step 1: [Name]
[Description]
\`\`\`bash
[Commands]
\`\`\`
### Step 2: [Name]
[Description]
## Verification
- [ ] [Check 1]
- [ ] [Check 2]
## Troubleshooting
| Problem | Solution |
|---------|----------|
| [Issue] | [Fix] |
---
name: api-reference
description: Quick reference for [API/Library].
---
# [API/Library] Reference
## When to Activate
- Using [API/Library]
- Looking up [API/Library] syntax
## Common Operations
### Operation 1
\`\`\`typescript
// Basic usage
\`\`\`
### Operation 2
\`\`\`typescript
// Advanced usage
\`\`\`
## Configuration
[Include config examples]
## Error Handling
[Include error patterns]
Copy to Claude Code skills directory:
cp -r skills/your-skill-name ~/.claude/skills/
Test with Claude Code:
You: "I need to [task that should trigger your skill]"
Claude should reference your skill's patterns.
Verify activation:
Test all code examples:
# From the repo root
npx tsc --noEmit skills/your-skill-name/examples/*.ts
# Or from inside the skill directory
npx tsc --noEmit examples/*.ts
# From the repo root
python -m py_compile skills/your-skill-name/examples/*.py
# Or from inside the skill directory
python -m py_compile examples/*.py
# From the repo root
go build ./skills/your-skill-name/examples/...
# Or from inside the skill directory
go build ./examples/...
gh repo fork affaan-m/everything-claude-code --clone
cd everything-claude-code
git checkout -b feat/skill-your-skill-name
mkdir -p skills/your-skill-name
# Create SKILL.md
# Check YAML frontmatter
head -10 skills/your-skill-name/SKILL.md
# Verify structure
ls -la skills/your-skill-name/
# Run tests if available
npm test
git add skills/your-skill-name/
git commit -m "feat(skills): add your-skill-name skill"
git push -u origin feat/skill-your-skill-name
Use this PR template:
## Summary
Brief description of the skill and why it's valuable.
## Skill Type
- [ ] Language standards
- [ ] Framework patterns
- [ ] Workflow
- [ ] Domain knowledge
- [ ] Tool integration
## Testing
How I tested this skill locally.
## Checklist
- [ ] YAML frontmatter valid
- [ ] Code examples tested
- [ ] Follows skill guidelines
- [ ] No sensitive data
- [ ] Clear activation triggers
File: skills/rust-patterns/SKILL.md
---
name: rust-patterns
description: Rust idioms, ownership patterns, and best practices for safe, idiomatic code.
origin: ECC
---
# Rust Patterns
## When to Activate
- Writing Rust code
- Handling ownership and borrowing
- Error handling with Result/Option
- Implementing traits
## Ownership Patterns
### Borrowing Rules
\`\`\`rust
// PASS: CORRECT: Borrow when you don't need ownership
fn process_data(data: &str) -> usize {
data.len()
}
// PASS: CORRECT: Take ownership when you need to modify or consume
fn consume_data(data: Vec<u8>) -> String {
String::from_utf8(data).unwrap()
}
\`\`\`
## Error Handling
### Result Pattern
\`\`\`rust
use thiserror::Error;
#[derive(Error, Debug)]
pub enum AppError {
#[error("IO error: {0}")]
Io(#[from] std::io::Error),
#[error("Parse error: {0}")]
Parse(#[from] std::num::ParseIntError),
}
pub type AppResult<T> = Result<T, AppError>;
\`\`\`
## Related Skills
- `rust-testing`
- `rust-security`
File: skills/fastapi-patterns/SKILL.md
---
name: fastapi-patterns
description: FastAPI patterns for routing, dependency injection, validation, and async operations.
origin: ECC
---
# FastAPI Patterns
## When to Activate
- Building FastAPI applications
- Creating API endpoints
- Implementing dependency injection
- Handling async database operations
## Project Structure
\`\`\`
app/
├── main.py # FastAPI app entry point
├── routers/ # Route handlers
│ ├── users.py
│ └── items.py
├── models/ # Pydantic models
│ ├── user.py
│ └── item.py
├── services/ # Business logic
│ └── user_service.py
└── dependencies.py # Shared dependencies
\`\`\`
## Dependency Injection
\`\`\`python
from fastapi import Depends
from sqlalchemy.ext.asyncio import AsyncSession
async def get_db() -> AsyncSession:
async with AsyncSessionLocal() as session:
yield session
@router.get("/users/{user_id}")
async def get_user(
user_id: int,
db: AsyncSession = Depends(get_db)
):
# Use db session
pass
\`\`\`
## Related Skills
- `python-patterns`
- `pydantic-validation`
File: skills/refactoring-workflow/SKILL.md
---
name: refactoring-workflow
description: Systematic refactoring workflow for improving code quality without changing behavior.
origin: ECC
---
# Refactoring Workflow
## When to Activate
- Improving code structure
- Reducing technical debt
- Simplifying complex code
- Extracting reusable components
## Prerequisites
- All tests passing
- Git working directory clean
- Feature branch created
## Workflow Steps
### Step 1: Identify Refactoring Target
- Look for code smells (long methods, duplicate code, large classes)
- Check test coverage for target area
- Document current behavior
### Step 2: Ensure Tests Exist
\`\`\`bash
# Run tests to verify current behavior
npm test
# Check coverage for target files
npm run test:coverage
\`\`\`
### Step 3: Make Small Changes
- One refactoring at a time
- Run tests after each change
- Commit frequently
### Step 4: Verify Behavior Unchanged
\`\`\`bash
# Run full test suite
npm test
# Run E2E tests
npm run test:e2e
\`\`\`
## Common Refactorings
| Smell | Refactoring |
|-------|-------------|
| Long method | Extract method |
| Duplicate code | Extract to shared function |
| Large class | Extract class |
| Long parameter list | Introduce parameter object |
## Checklist
- [ ] Tests exist for target code
- [ ] Made small, focused changes
- [ ] Tests pass after each change
- [ ] Behavior unchanged
- [ ] Committed with clear message
Remember: A good skill is focused, actionable, and immediately useful. Write skills you'd want to use yourself.