# Backend Development

Backend API design, database architecture, microservices patterns, and test-driven...

- Repository: https://github.com/MoizIbnYousaf/ai-agent-skills (1155 stars)
- Category: Design
- License: MIT
- Last updated: 2026-09-21
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add MoizIbnYousaf/ai-agent-skills --skill backend-development -g -a claude-code -y`
Codex: `npx skills add MoizIbnYousaf/ai-agent-skills --skill backend-development -g -a codex -y`
Cursor: `npx skills add MoizIbnYousaf/ai-agent-skills --skill backend-development -g -a cursor -y`
Gemini CLI: `npx skills add MoizIbnYousaf/ai-agent-skills --skill backend-development -g -a gemini-cli -y`

## Description

Backend API design, database architecture, microservices patterns, and test-driven development. Use for designing APIs, database schemas, or backend system architecture.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Backend Development

## API Design

### RESTful Conventions
```
GET    /users          # List users
POST   /users          # Create user
GET    /users/:id      # Get user
PUT    /users/:id      # Update user (full)
PATCH  /users/:id      # Update user (partial)
DELETE /users/:id      # Delete user

GET    /users/:id/posts  # List user's posts
POST   /users/:id/posts  # Create post for user
```

### Response Format
```json
{
  "data": { ... },
  "meta": {
    "page": 1,
    "per_page": 20,
    "total": 100
  }
}
```

### Error Format
```json
{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid input",
    "details": [
      { "field": "email", "message": "Invalid format" }
    ]
  }
}
```

## Database Patterns

### Schema Design
```sql
-- Use UUIDs for public IDs
CREATE TABLE users (
  id SERIAL PRIMARY KEY,
  public_id UUID DEFAULT gen_random_uuid() UNIQUE,
  email VARCHAR(255) UNIQUE NOT NULL,
  created_at TIMESTAMPTZ DEFAULT NOW(),
  updated_at TIMESTAMPTZ DEFAULT NOW()
);

-- Soft deletes
ALTER TABLE users ADD COLUMN deleted_at TIMESTAMPTZ;

-- Indexes
CREATE INDEX idx_users_email ON users(email);
CREATE INDEX idx_users_created ON users(created_at DESC);
```

### Query Patterns
```sql
-- Pagination with cursor
SELECT * FROM posts
WHERE created_at < $cursor
ORDER BY created_at DESC
LIMIT 20;

-- Efficient counting
SELECT reltuples::bigint AS estimate
FROM pg_class WHERE relname = 'users';
```

## Authentication

### JWT Pattern
```typescript
interface TokenPayload {
  sub: string;      // User ID
  iat: number;      // Issued at
  exp: number;      // Expiration
  scope: string[];  // Permissions
}

function verifyToken(token: string): TokenPayload {
  return jwt.verify(token, SECRET) as TokenPayload;
}
```

The rest: https://github.com/MoizIbnYousaf/ai-agent-skills/blob/HEAD/skills/backend-development/SKILL.md