Video Generation API

Generate short AI videos with xAI's Grok Imagine or ByteDance's Seedance. Text or image prompt in, MP4 URL out.

Endpoint

POST https://blockrun.ai/api/v1/videos/generations

Request

{
  "model": "xai/grok-imagine-video",
  "prompt": "a red apple slowly spinning on a wooden table, daylight",
  "image_url": "https://example.com/seed.jpg"
}

Parameters

Parameter	Type	Required	Description
`model`	string	Yes	Video model ID (see below)
`prompt`	string	Yes	Text description of the video to generate
`image_url`	string	No	Optional seed image URL for image-to-video
`duration_seconds`	integer	No	Duration billed for (defaults to model's default)

Available Models

Model ID	Provider	Default / Max	Billing
`xai/grok-imagine-video`	xAI	8s / 8s MP4	$0.050/second (default 8s = $0.42 with margin)
`bytedance/seedance-1.5-pro`	ByteDance	5s / 10s MP4	$0.030/second (default 5s = $0.158 with margin)
`bytedance/seedance-2.0-fast`	ByteDance	5s / 10s MP4	$0.150/second (default 5s = $0.788 with margin)
`bytedance/seedance-2.0`	ByteDance	5s / 10s MP4	$0.300/second (default 5s = $1.575 with margin)

All models accept text prompts and an optional image_url for image-to-video. Output is 720p MP4. seedance-2.0-fast generates in ~60–80 s; seedance-2.0 (Pro) may take longer and can occasionally hit the 85 s timeout — in that case the request returns 504 and no payment is taken.

Response

{
  "created": 1776443975,
  "model": "xai/grok-imagine-video",
  "data": [
    {
      "url": "https://blockrun.ai/api/media/media/videos/2026/04/17/<id>.mp4",
      "source_url": "https://vidgen.x.ai/xai-vidgen-bucket/xai-video-<id>.mp4",
      "duration_seconds": 8,
      "request_id": "<xai-request-id>",
      "backed_up": true
    }
  ]
}

Response Fields

Field	Type	Description
`created`	integer	Unix timestamp
`data[].url`	string	Permanent URL. When GCS backup succeeds, this is a blockrun-hosted proxy URL; otherwise the upstream URL
`data[].source_url`	string	Original upstream URL from xAI (temporary — may expire)
`data[].duration_seconds`	integer	Duration of the generated video
`data[].request_id`	string	xAI request ID for debugging / deduplication
`data[].backed_up`	boolean	`true` when the video was mirrored to BlockRun's GCS bucket

Why both url and source_url? xAI's vidgen.x.ai URLs are temporary. BlockRun mirrors each generated video to Google Cloud Storage and returns the permanent proxy URL as url. source_url is kept for debugging. If the backup step fails, url falls back to the upstream URL and backed_up is false.

Timing

Video generation is asynchronous upstream. This endpoint handles the full polling loop so you only need to make a single request.

Phase	Typical latency
Request → xAI job submitted	~1s
Polling until video ready	15–60s (typically under 30s)
GCS backup + settle payment	1–3s
Total	~20–60s

The connection stays open until the video is ready. Make sure your HTTP client allows at least 180s.

Examples

Via ClawRouter (recommended for local use)

ClawRouter handles x402 payments automatically.

curl -X POST http://localhost:8402/v1/videos/generations \
  -H "Content-Type: application/json" \
  -d '{
    "model": "xai/grok-imagine-video",
    "prompt": "a neon-lit cyberpunk street at night, camera slowly dollying forward"
  }'

Direct API (cURL)

curl -X POST https://blockrun.ai/api/v1/videos/generations \
  -H "Content-Type: application/json" \
  -H "X-Payment: $PAYMENT_HEADER" \
  -d '{
    "model": "xai/grok-imagine-video",
    "prompt": "a hummingbird hovering in front of a red flower, ultra slow motion"
  }'

Image-to-video

curl -X POST http://localhost:8402/v1/videos/generations \
  -H "Content-Type: application/json" \
  -d '{
    "model": "xai/grok-imagine-video",
    "prompt": "the subject turns its head and smiles",
    "image_url": "https://example.com/portrait.jpg"
  }'

Pricing

Model	Unit	Price	Margin	Default billed
`xai/grok-imagine-video`	per second	$0.050	5%	8s = $0.420
`bytedance/seedance-1.5-pro`	per second	$0.030	5%	5s = $0.158
`bytedance/seedance-2.0-fast`	per second	$0.150	5%	5s = $0.788
`bytedance/seedance-2.0`	per second	$0.300	5%	5s = $1.575

Error Codes

Code	Description
400	Invalid request (bad prompt, parameters, or `duration_seconds` above model max)
402	Payment required or payment verification/settlement failed
403	Content policy violation
429	Rate limit exceeded (xAI caps at 60 RPM)
500	Server error
504	Video generation timed out (upstream job did not finish within the 85s cap). No payment is taken.