Seedance 2.0 FastAPI 参考

{
  "id": "evt_01J9ZKB1QX",
  "type": "job.succeeded",
  "created_at": "2026-09-29T14:02:31Z",
  "data": {
    "job": {
      "id": "job_01J9ZK4T8W",
      "object": "job",
      "kind": "video",
      "status": "succeeded",
      "money_status": "settled",
      "requested_model": "seedance-2.0-fast",
      "credits_charged": 34,
      "outputs": [
        {
          "kind": "video",
          "url": "https://…/job_01J9ZK4T8W.mp4?sig=…"
        }
      ]
    }
  }
}

import { createHmac, timingSafeEqual } from "node:crypto";

// rawBody: the request body exactly as received, before any JSON parsing.
export function verifyWebhook(header, rawBody, secret, toleranceSec = 300) {
  let t = null;
  const signatures = [];
  for (const item of (header ?? "").split(",")) {
    const [key, value] = item.split("=", 2);
    if (key === "t") t = Number(value);
    if (key === "v1") signatures.push(Buffer.from(value, "hex"));
  }
  if (!t || Math.abs(Date.now() / 1000 - t) > toleranceSec) return false;
  const expected = createHmac("sha256", secret).update(`${t}.${rawBody}`).digest();
  return signatures.some((s) => s.length === expected.length && timingSafeEqual(s, expected));
}

// verifyWebhook(req.headers["x-signature"], rawBody, process.env.WEBHOOK_SECRET)
// Answer 2xx quickly, and skip an X-Event-Id you have already handled.