Quickstart

Authentication

All requests must include a bearer token. Keys are scoped to environment (live or test) and rate-limited independently.

Authorization: Bearer nxa_live_sk_9fa0b1c8...4e2a
X-NextAPI-Environment: live

Create a job

Submits a Seedance generation. Returns a job_id and reserves credits against your balance. Credits are reconciled to the final amount on job.succeeded or fully refunded on job.failed.

1curl https://api.nextapi.top/v1/video/generations \
2  -H "Authorization: Bearer $NEXTAPI_KEY" \
3  -H "Idempotency-Key: 9c4fa1b2" \
4  -H "Content-Type: application/json" \
5  -d {
6    "model": "seedance-2.0-pro",
7    "prompt": "Drone orbiting a lighthouse at dusk",
8    "duration_seconds": 6,
9    "resolution": "1080p"
10  }

1{
2  "id": "job_7Hc9Xk2Lm3NpQ4rS",
3  "status": "queued",
4  "estimated_credits": 1.0
5}

Webhook events

Every job transition emits exactly one webhook. Events are ordered and at-least-once. Use the event.id for deduplication.

Signature verification

Every webhook includes an X-NextAPI-Signature header. Verify the HMAC-SHA256 before trusting the payload.

1import crypto from "node:crypto"
2
3export function verify(rawBody, header, secret) {
4  const [tPart, vPart] = header.split(",")
5  const t = tPart.split("=")[1]
6  const v = vPart.split("=")[1]
7
8  const expected = crypto
9    .createHmac("sha256", secret)
10    .update(`${t}.${rawBody}`)
11    .digest("hex")
12
13  const fresh = Math.abs(Date.now() / 1000 - Number(t)) < 300
14  return fresh && crypto.timingSafeEqual(
15    Buffer.from(expected),
16    Buffer.from(v),
17  )
18}

Idempotency

Include an Idempotency-Key header on POST requests to safely retry without creating duplicate jobs. Keys are scoped per API key and expire after 24 hours.

Retrieve a Video

Fetch the current state of a generation job by its ID. Returns the video URL once generation completes, or the current status and progress otherwise.

List Videos

Returns a paginated list of generation jobs for the authenticated organization. Use ?limit= and ?offset= for pagination.

Webhook Retries

Webhooks are retried with exponential backoff up to 5 times. If your endpoint returns a non-2xx status, we retry at 1m, 5m, 30m, 2h, and 12h intervals. Each delivery includes the same X-Webhook-Signature header.

Rate Limits

API requests are rate-limited per key. Limits are returned in response headers: X-RateLimit-Remaining and X-RateLimit-Reset. Default: 600 requests/minute for business keys, 300/min for admin keys. Enterprise customers can negotiate higher limits.

Error Codes

All errors follow a consistent JSON format with error.code and error.message. Common codes: invalid_request, unauthorized, rate_limit_exceeded, insufficient_credits, internal_error.

Changelog