Webhook

{
  "event": "conversion.completed",
  "data": {
    "conversionId": "conv_abc123",
    "url": "https://example.com/article",
    "title": "Example Article",
    "markdownLength": 4820,
    "timestamp": "2026-03-21T12:00:00.000Z"
  }
}

const crypto = require("crypto");

function verifyWebhookSignature(payload, signature, secret) {
  const expected = crypto
    .createHmac("sha256", secret)
    .update(payload)
    .digest("hex");
  return crypto.timingSafeEqual(
    Buffer.from(signature),
    Buffer.from(expected)
  );
}

// リクエストハンドラー内:
app.post("/webhooks/web2md", (req, res) => {
  const signature = req.headers["x-web2md-signature"];
  const rawBody = JSON.stringify(req.body);

  if (!verifyWebhookSignature(rawBody, signature, process.env.WEB2MD_WEBHOOK_SECRET)) {
    return res.status(401).send("Invalid signature");
  }

  const { event, data } = req.body;
  console.log(`Conversion completed: ${data.title} (${data.url})`);

  res.status(200).send("OK");
});