LTX 2.3 Fast Image to Video

POST/v1/run

Ltx 2.3 Fast is Lightricks's image-to-video AI model. Bring static images to life with fluid animation, consistent character motion, and professional-grade video output.

Request body

Submit an async generation request. The model field selects the model; other fields are model-specific input parameters.

stringmodelrequired

Model identifier. Set to lightricks/ltx-2.3-fast/image-to-video.

Default: lightricks/ltx-2.3-fast/image-to-video

stringpromptrequired

The prompt to generate the video from

stringimagerequired

URL of the image to generate the video from. Must be publicly accessible or base64 data URI. Supports PNG, JPEG, WebP, AVIF, and HEIF formats.

Optional<string>end_image

The URL of the end image to use for the generated video. When provided, generates a transition video between start and end frames.

Optional<string>resolution

The resolution of the generated video

Allowed values: 1080p, 1440p, 2160p

Default: 1080p

Optional<integer>duration

The duration of the generated video in seconds. The fast model supports 6-20 seconds. Note: Durations longer than 10 seconds (12, 14, 16, 18, 20) are only supported with 25 FPS and 1080p resolution.

Allowed values: 6, 8, 10, 12, 14, 16, 18, 20

Default: 6

Optional<boolean>generate_audio

Whether to generate audio for the generated video

Default: true

Optional<string>aspect_ratio

The aspect ratio of the generated image.

Allowed values: 21:9, 16:9, 3:2, 4:3, 5:4, 1:1, 4:5, 3:4, 2:3, 9:16

Response Schema

The submit endpoint returns an accepted generation task. Poll the result endpoint with the returned id for terminal outputs or errors.

Optional<string>error

Error message if the task failed. Empty on success.

stringidrequired

Unique identifier for the generation task.

Optional<string>model

Model ID used for the prediction.

Optional<array>outputs

Array of generated content. Empty when status is not completed.

stringstatusrequired

Status of the task: pending, running, completed, failed, or timeout.

Allowed values: pending, running, completed, failed, timeout

Model capabilities

array<string>capability_tagsrequired

Capabilities declared by the model registry.

Default: image-to-video

stringexecution_moderequired

Execution mode declared by the model registry.

Default: async

# 1. Submit a generation request
curl -X POST https://api.sandbase.ai/v1/run \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "lightricks/ltx-2.3-fast/image-to-video",
  "prompt": "Snorkel lens ground-scraping tracking shot following a barefoot Ethiopian long-distance runner training on a dirt road at dawn, camera inches from the ground racing alongside, her feet kicking up red dust in slow motion at 240fps, Rift Valley landscape blurred in the background, the texture of earth and callused skin in hyper-detail, 40mm snorkel lens at ground height, Nike Running documentary meets Lubezki natural light, the poetry of human endurance",
  "image": "https://static.sandbase.ai/examples/lightricks/ltx-2.3-fast/image-to-video/input_image_0.png",
  "duration": 6,
  "aspect_ratio": "21:9"
}'

# 2. If the response is still running, poll the returned id
curl https://api.sandbase.ai/v1/run/run_abc123 \
  -H "Authorization: Bearer $SANDBASE_API_KEY"

Response202 Accepted

{
  "id": "run_abc123",
  "model": "lightricks/ltx-2.3-fast/image-to-video",
  "status": "running",
  "outputs": []
}