API Endpoint Scaffolder skill

API Endpoint Scaffolder

Instructions

When creating a new API endpoint:

1. Identify the framework (Express, Next.js, FastAPI, etc.)
2. Determine HTTP method (GET, POST, PUT, PATCH, DELETE)
3. Define request/response types
4. Implement with best practices

Templates

Next.js App Router (TypeScript)

// app/api/[resource]/route.ts
import { NextRequest, NextResponse } from 'next/server';
import { z } from 'zod';

const RequestSchema = z.object({
  // Define your schema
});

export async function GET(request: NextRequest) {
  try {
    const { searchParams } = new URL(request.url);
    // Implementation
    return NextResponse.json({ data }, { status: 200 });
  } catch (error) {
    console.error('[API] Error:', error);
    return NextResponse.json(
      { error: 'Internal server error' },
      { status: 500 }
    );
  }
}

export async function POST(request: NextRequest) {
  try {
    const body = await request.json();
    const validated = RequestSchema.parse(body);
    // Implementation
    return NextResponse.json({ data }, { status: 201 });
  } catch (error) {
    if (error instanceof z.ZodError) {
      return NextResponse.json(
        { error: 'Validation failed', details: error.errors },
        { status: 400 }
      );
    }
    return NextResponse.json(
      { error: 'Internal server error' },
      { status: 500 }
    );
  }
}

Express (TypeScript)

import { Router, Request, Response, NextFunction } from 'express';
import { z } from 'zod';

const router = Router();

const CreateSchema = z.object({
  // Define schema
});

router.post('/', async (req: Request, res: Response, next: NextFunction) => {
  try {
    const data = CreateSchema.parse(req.body);
    // Implementation
    res.status(201).json({ success: true, data });
  } catch (error) {
    next(error);
  }
});

export default router;

Best Practices

1. Always validate input using Zod, Yup, or similar
2. Use proper HTTP status codes:
   • 200: Success
   • 201: Created
   • 400: Bad Request
   • 401: Unauthorized
   • 403: Forbidden
   • 404: Not Found
   • 500: Server Error
3. Log errors but don't expose internals to clients
4. Use consistent response format
5. Add rate limiting for public endpoints
6. Document with OpenAPI/Swagger when possible