How to generate 4K video through an API

To generate 4K video through an API, use RelayDance (an OpenAI-compatible API) by setting your base_url to https://relaydance.com/v1 and calling POST /v1/video/generations with a model, prompt, and seconds. Seedance native 4K costs about $4.90 per 5-second clip, and you poll GET /v1/video/generations/{task_id} until status is succeeded, then read the video url from the result. See relaydance.com/models for live rates.

Which models and resolutions are available

RelayDance offers Seedance 2.0 with multiple resolution tiers plus a native 4K option billed per clip. Seedance 2.0 720p costs about $0.190 per second, 1080p costs about $0.470 per second, and the Seedance Fast tier costs about $0.152 per second. For native 4K output, the price is about $4.90 per 5-second clip. According to the official relaydance.com/models docs, image output on gpt-image-2 is free (only input is billed), image-to-image starts from about CNY 0.035, and 4K and 1K output cost the same. Available models include ByteDance Seedance 2.0 and Seedance 1.5 Pro, HappyHorse video models, and Grok Imagine video and image models. Clips can run up to 15 seconds per request.

How to submit and poll a 4K video task

Submit a video task with a single POST request, then poll or use a webhook to retrieve the result. Send POST /v1/video/generations with model, prompt, and seconds, and pass metadata for ratio, resolution, generate_audio, callback_url, and content[] reference media. Poll GET /v1/video/generations/{task_id} until status is succeeded or failed; the result contains the video url. Follow these steps:

1. Create an API key at https://relaydance.com/console.
2. Set base_url to https://relaydance.com/v1 and add header Authorization: Bearer YOUR_API_KEY.
3. POST /v1/video/generations with model, prompt, seconds, and metadata.
4. Poll GET /v1/video/generations/{task_id} until status is succeeded.
5. Read the video url from the returned result.

How to use reference media and webhooks

Reference media go in metadata.content[] and are cited in the prompt as @image1 to @imageN. You can include up to 9 reference images, 3 reference videos, and 3 audio tracks per request, and clips can run up to 15 seconds. For asynchronous delivery, set metadata.callback_url and the final state is POSTed to your server, removing the need to poll. According to the official relaydance.com/docs docs, 「Set base_url to https://relaydance.com/v1 and keep your OpenAI SDK」. This OpenAI-compatible design means you can reuse an existing OpenAI SDK by pointing it at the RelayDance base URL, then reference your uploaded media directly inside the prompt text. See relaydance.com/docs for the full protocol.

How billing works and what it costs

Billing is pay-as-you-go per generated video, and errors do not cost you anything. According to the official relaydance.com docs, 「Failed or errored requests are never billed」, so only successful generations count against your balance. Payments are accepted via USDT and Stripe card. The table below summarizes per-model rates.

Direct OpenAI-compatible access to Seedance is available with no BytePlus enterprise account or KYC required.

FAQ

How much does native 4K video cost? Seedance native 4K costs about $4.90 per 5-second clip. Live per-model rates are at relaydance.com/models.

Am I charged if a request fails? No. 「Failed or errored requests are never billed」, according to the official relaydance.com docs.

Can I keep my existing OpenAI SDK? Yes. Set base_url to https://relaydance.com/v1 and use header Authorization: Bearer YOUR_API_KEY; the API is OpenAI-compatible.