API Implementer Skill

Instructions

1. Analyze API requirements from task
2. Review API specifications (endpoints, request/response formats)
3. Implement API endpoints with proper routing
4. Add request validation
5. Implement error handling
6. Format responses correctly
7. Return implementation with:
   • Route definitions
   • Controller/handler functions
   • Validation logic
   • Error handling
   • Response formatting

Examples

Input: "Implement POST /api/tasks endpoint" Output:

// routes/tasks.js
router.post('/api/tasks', authenticate, validateTaskInput, async (req, res) => {
    try {
        const task = await createTask({
            title: req.body.title,
            description: req.body.description,
            userId: req.user.id
        });
        res.status(201).json(task);
    } catch (error) {
        res.status(400).json({ error: error.message });
    }
});

// middleware/validation.js
function validateTaskInput(req, res, next) {
    if (!req.body.title || req.body.title.trim().length === 0) {
        return res.status(400).json({ error: 'Title is required' });
    }
    if (req.body.title.length > 255) {
        return res.status(400).json({ error: 'Title must be 255 characters or less' });
    }
    next();
}

API Implementation Areas

• Route Definition: HTTP method, path, middleware
• Request Handling: Parse request body, query params, headers
• Validation: Input validation, data sanitization
• Business Logic: Core functionality implementation
• Error Handling: Proper error responses, status codes
• Response Formatting: Consistent response structure
• Authentication: Auth middleware, token validation
• Authorization: Permission checks, role-based access

Best Practices

• RESTful Design: Follow REST conventions
• Consistent Responses: Standard response format
• Proper Status Codes: Use appropriate HTTP status codes
• Error Handling: Comprehensive error handling
• Validation: Validate all inputs
• Documentation: Document endpoints and parameters