API Integration Builder

# API Integration Builder Skill

## Integration Checklist
1. **Authentication**: OAuth2, API key, or JWT?
2. **Rate Limiting**: respect headers, implement backoff
3. **Error Handling**: retry transient, surface permanent
4. **Webhook Verification**: validate signatures

## REST Client Template
```typescript
const client = {
  baseURL: "https://api.example.com/v1",
  headers: { Authorization: `Bearer ${API_KEY}` },
  retry: { attempts: 3, backoff: "exponential" },
  timeout: 30_000,
};
```

## Error Handling Strategy
- 400: Log request body, surface validation errors
- 401/403: Refresh token, retry once
- 429: Read Retry-After header, wait and retry
- 500+: Retry with exponential backoff (max 3)