api-endpoint-scaffolder

name	api-endpoint-scaffolder
description	Scaffolds REST API endpoints with route handler, validation, error handling, and tests. Use when asked to create a new API endpoint or route.
license	MIT
allowed-tools	Read Glob Grep Edit Write Bash

API Endpoint Scaffolder

When asked to create a new API endpoint, follow this process:

Step 1: Detect Framework

Read the project to determine the framework in use:

• Express/Fastify — look for app.get(), router.post(), package.json deps
• Next.js App Router — look for app/api/ directory
• Next.js Pages Router — look for pages/api/ directory
• Hono/Elysia — check package.json

Match the existing patterns and conventions in the codebase.

Step 2: Scaffold the Endpoint

Generate these files for each endpoint:

Route Handler

• Parse and validate request body/params/query using Zod or the project's validation library
• Return proper HTTP status codes (200, 201, 400, 404, 500)
• Include error handling with descriptive messages
• Add TypeScript types for request and response

Validation Schema

import { z } from "zod";

export const createUserSchema = z.object({
  name: z.string().min(1).max(100),
  email: z.string().email(),
});

export type CreateUserInput = z.infer<typeof createUserSchema>;

Response Format

Always use a consistent response envelope:

{
  "success": true,
  "data": { ... }
}

{
  "success": false,
  "error": { "message": "...", "code": "VALIDATION_ERROR" }
}

Step 3: Add Tests

Create a test file covering:

• Happy path (valid request returns expected response)
• Validation errors (invalid input returns 400)
• Not found (missing resource returns 404)
• Authentication (if endpoint is protected)

Rules

• Never hardcode secrets or connection strings
• Always validate all user input before processing
• Use parameterized queries for database operations, never string concatenation
• Log errors but don't expose internal details to the client
• Follow the existing project conventions for file placement and naming