App Router मा Route Handlers (API routes) के हुन्?

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Accepted Answer

**Route Handlers** App Router को API endpoints बनाउने तरिका हो — backend HTTP handlers जो तपाइंको Next.js project मा रहन्छन्। तपाइं तिनलाई **`route.ts`** फाइलको साथ बनाउनुहुन्छ, HTTP methods को नाम राखेर functions export गर्दै।

## एक endpoint परिभाषित गर्नुहोस्

```ts
// app/api/users/route.ts  →  serves /api/users
import { NextRequest, NextResponse } from "next/server";

export async function GET() {
  const users = await db.user.findMany();
  return NextResponse.json(users);             // GET /api/users
}

export async function POST(req: NextRequest) {
  const body = await req.json();               // read the request body
  const user = await db.user.create({ data: body });
  return NextResponse.json(user, { status: 201 }); // POST /api/users
}
```

प्रत्येक exported method (`GET`, `POST`, `PUT`, `PATCH`, `DELETE`) त्यो verb लाई handle गर्दछ। तिनीहरूले standard Web `Request`/`Response` APIs (को माध्यमबाट `NextRequest`/`NextResponse`) प्रयोग गर्छन्।

## Params र query पढ्नुहोस्

```ts
// app/api/users/[id]/route.ts → /api/users/123
export async function GET(req: NextRequest, { params }: { params: { id: string } }) {
  const url = new URL(req.url);
  const sort = url.searchParams.get("sort"); // ?sort=name
  const user = await db.user.findUnique({ where: { id: params.id } });
  return NextResponse.json(user);
}
```

## कहिले Route Handlers बनाम Server Actions/Components प्रयोग गर्ने

```text
Use Route Handlers for:
  ✓ Public APIs consumed by mobile apps / external clients
  ✓ Webhooks (Stripe, GitHub) — they need a URL endpoint
  ✓ Returning non-HTML (JSON, files, images, RSS)
  ✓ Client-side fetch() targets

Prefer Server Components for reading data into your own pages,
and Server Actions for form mutations — they avoid a manual API layer.
```

## अन्य क्षमताहरु

```ts
export const runtime = "edge";       // run on the Edge runtime
export const dynamic = "force-dynamic"; // opt out of caching
// Handlers can also stream responses, set cookies, and handle CORS.
```

## किन यो महत्त्वपूर्ण छ

Route Handlers ले Next.js लाई full-stack बनाउदछ: तपाइं REST/JSON APIs, webhooks, र फाइल endpoints बनाउनुहुन्छ तपाइंको frontend सँग web-standard `Request`/`Response` को साथ।

कहिले तिनलाई पहुँच गर्ने (external clients, webhooks, non-HTML responses) बनाम Server Components/Actions (internal data reads र mutations) को प्रयोग गर्ने भनेर जान्नु एक App Router backend लाई सफलतापूर्वक संरचित गर्न महत्त्वपूर्ण छ।