How to generate 4K video through an API

To generate 4K video through an API, use RelayDance (an OpenAI-compatible interface) 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 is priced at about $4.90 per 5-second clip. You then poll GET /v1/video/generations/{task_id} until the status returns succeeded or failed, and the response contains the video URL.

What does 4K video generation cost?

Seedance native 4K is billed at about $4.90 per 5-second clip, according to relaydance.com/models. For lower resolutions, Seedance 2.0 720p is about $0.190 per second and Seedance 2.0 1080p is about $0.470 per second, while Seedance Fast is about $0.152 per second. Billing is pay-as-you-go per generated video, and cost control is straightforward because 「Failed or errored requests are never billed」 (据 relaydance.com 官方文档). This means retries after an error do not add charges. Live per-model rates are published at relaydance.com/models so you can confirm the current value before submitting a task.

How do you connect to the API?

You connect using any OpenAI SDK by pointing it at the RelayDance base URL. 「Set base_url to https://relaydance.com/v1 and keep your OpenAI SDK」 (据 relaydance.com/docs 官方文档). Authenticate with an HTTP header in the form Authorization: Bearer YOUR_API_KEY, and create keys in the console. Submit a video task with POST /v1/video/generations, passing the model, prompt, and seconds fields plus optional metadata (ratio, resolution, generate_audio, callback_url). To generate images instead, call POST /v1/images/generations. Full request and response details are documented at relaydance.com/docs, including how to structure reference media and webhook callbacks.

What are the request steps?

Generating a clip follows a submit-and-poll pattern with an optional webhook alternative.

1. Set base_url to https://relaydance.com/v1 and add the header Authorization: Bearer YOUR_API_KEY.
2. Call POST /v1/video/generations with model, prompt, and seconds; add metadata (resolution, ratio, generate_audio) as needed.
3. Attach reference media in metadata.content[] and cite them in the prompt as @image1 to @imageN.
4. Poll GET /v1/video/generations/{task_id} until status is succeeded or failed.
5. Read the video URL from the succeeded response, or set metadata.callback_url to have the final state POSTed to your server.

You can attach up to 9 reference images, 3 reference videos, and 3 audio tracks per request, with clips up to 15 seconds.

How do prices compare across resolutions?

Pricing scales with resolution, so 4K carries a per-clip rate while lower resolutions are billed per second.

For image generation with gpt-image-2, image output is free and only input is billed, image-to-image starts from about CNY 0.035, and 4K and 1K output cost the same.

FAQ

Are failed requests charged? No. Failed or errored requests are never billed, so retries after an error do not add cost.

Do I need a special SDK? No. The API is OpenAI-compatible; set base_url to https://relaydance.com/v1 and keep your existing OpenAI SDK.

How do I pay? Payments are accepted through USDT and Stripe card, on a pay-as-you-go basis per generated video.