# Menerima webhook

> Handler webhook terverifikasi untuk route handler Next.js, Express, Cloudflare Worker, dan Python.

Setiap handler melakukan empat hal yang sama: membaca body mentah, memverifikasi tanda tangan, mengabaikan pengiriman yang sudah ditangani, dan menjawab `2xx` dalam 15 detik. Payload dan header-nya dijelaskan di [Webhook](https://ikiform.com/id/docs/webhooks.md).

## Route handler Next.js

`app/api/webhooks/ikiform/route.ts`:

```ts
import { verifyWebhook, WebhookVerificationError } from "@ikiform/sdk/webhooks";

export async function POST(request: Request) {
  const payload = await request.text();
  try {
    const event = await verifyWebhook({
      payload,
      headers: request.headers,
      secret: process.env.IKIFORM_WEBHOOK_SECRET!,
    });
    if (event.type === "submission.created") {
      await saveLead(event.id, event.data.fields);
    }
    return new Response(null, { status: 204 });
  } catch (error) {
    if (error instanceof WebhookVerificationError) {
      return new Response(error.reason, { status: 400 });
    }
    throw error;
  }
}
```

`request.text()` memberi body mentah. Jangan panggil `request.json()` lebih dulu; JSON yang diserialisasi ulang tidak lagi cocok dengan tanda tangan.

## Express

`server.js`:

```js
import express from "express";
import { verifyWebhook, WebhookVerificationError } from "@ikiform/sdk/webhooks";

const app = express();

app.post("/webhooks/ikiform", express.text({ type: "application/json" }), async (req, res) => {
  try {
    const event = await verifyWebhook({
      payload: req.body,
      headers: req.headers,
      secret: process.env.IKIFORM_WEBHOOK_SECRET,
    });
    if (event.type === "submission.created") await saveLead(event.id, event.data.fields);
    res.status(204).end();
  } catch (error) {
    if (error instanceof WebhookVerificationError) return res.status(400).send(error.reason);
    res.status(500).end();
  }
});

app.listen(3000);
```

`express.text({ type: "application/json" })` mempertahankan body sebagai string persis yang dikirim Ikiform. `express.json()` global akan mengurainya lebih dulu, jadi pasang route webhook sebelum itu atau kecualikan path ini.

## Cloudflare Worker

`src/index.ts`:

```ts
import { verifyWebhook, WebhookVerificationError } from "@ikiform/sdk/webhooks";

interface Env {
  IKIFORM_WEBHOOK_SECRET: string;
  LEADS: KVNamespace;
}

export default {
  async fetch(request: Request, env: Env, ctx: ExecutionContext) {
    if (request.method !== "POST") return new Response(null, { status: 405 });
    const payload = await request.text();
    try {
      const event = await verifyWebhook({ payload, headers: request.headers, secret: env.IKIFORM_WEBHOOK_SECRET });
      if (event.type === "submission.created") {
        ctx.waitUntil(env.LEADS.put(event.id, JSON.stringify(event.data)));
      }
      return new Response(null, { status: 204 });
    } catch (error) {
      if (error instanceof WebhookVerificationError) return new Response(error.reason, { status: 400 });
      throw error;
    }
  },
};
```

SDK hanya memakai Web Crypto, jadi berjalan di Workers, Deno, dan Bun tanpa polyfill.

## Python

`app.py`:

```python
import base64
import hashlib
import hmac
import os
import time

from flask import Flask, abort, request

app = Flask(__name__)
secret = base64.b64decode(os.environ["IKIFORM_WEBHOOK_SECRET"].removeprefix("whsec_"))


def verify(body: bytes, headers) -> bool:
    msg_id = headers.get("webhook-id")
    timestamp = headers.get("webhook-timestamp")
    signatures = headers.get("webhook-signature")
    if not msg_id or not timestamp or not signatures or not timestamp.isdigit():
        return False
    if abs(time.time() - int(timestamp)) > 300:
        return False
    content = f"{msg_id}.{timestamp}.".encode() + body
    expected = base64.b64encode(hmac.new(secret, content, hashlib.sha256).digest()).decode()
    for entry in signatures.split(" "):
        version, _, signature = entry.partition(",")
        if version == "v1" and hmac.compare_digest(signature, expected):
            return True
    return False


@app.post("/webhooks/ikiform")
def ikiform_webhook():
    body = request.get_data()
    if not verify(body, request.headers):
        abort(400)
    event = request.get_json()
    if event["type"] == "submission.created":
        save_lead(event["id"], event["data"]["fields"])
    return "", 204
```

## Menangani duplikat

Sebuah pengiriman bisa tiba lebih dari sekali, misalnya saat server Anda sudah menanganinya tetapi responsnya timeout. Header `webhook-id` dan `id` di payload adalah ID pengiriman dan tetap sama di setiap percobaan ulang. Simpan dengan unique constraint dan lewati pekerjaan yang sudah Anda lakukan:

`leads.ts`:

```ts
async function saveLead(deliveryId: string, fields: Record<string, unknown>) {
  const inserted = await db.query(
    "insert into leads (delivery_id, fields) values ($1, $2) on conflict (delivery_id) do nothing returning id",
    [deliveryId, JSON.stringify(fields)],
  );
  if (inserted.rowCount === 0) return;
  await notifySales(fields);
}
```

## Menguji secara lokal

- Ikiform hanya mengirim ke URL `https:` publik di port 443, jadi `localhost` tidak akan berfungsi. Ekspos server lokal Anda dengan tunnel yang memberi URL HTTPS publik, lalu pakai URL itu untuk endpoint tes.
- Gunakan **Send test** di halaman endpoint. Tombol ini mengirim event `endpoint.test` sekali, tanpa percobaan ulang.
- Tempel pengiriman sungguhan ke [verifikator tanda tangan](https://ikiform.com/id/docs/webhooks.md#verifier) untuk memeriksa secret dan header Anda di browser.