Happy Horse 1.1 Reference to Video

POST/v1/run

Happy Horse 1.1 by Alibaba - animate still images into dynamic videos with AI. Transform photos into cinematic clips with natural motion, camera movement, and optional audio generation.

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 alibaba/happy-horse/1.1/reference-to-video.

Default: alibaba/happy-horse/1.1/reference-to-video

stringpromptrequired

Text prompt describing the desired video. Reference subjects from your images using ``character1``, ``character2``, ... up to ``character9`` (the order matches the order of ``image_urls``). Max 2500 characters.

Optional<array<string>>images

Reference images for subject consistency (1-9 images). Formats: JPEG, JPG, PNG, WEBP. Shortest side must be at least 400 px (720P or higher recommended). Max 20 MB each.

Optional<string>resolution

Output video resolution tier.

Allowed values: 720p, 1080p

Default: 1080p

Optional<integer>duration

Output video duration in seconds (3-15).

Allowed values: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15

Default: 5

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

Optional<integer>seed

Random seed for reproducibility (0-2147483647).

Response Schema

The submit endpoint returns a run response. If its status is pending or running, poll GET /v1/run/{id} with the returned opaque ID until it reaches a terminal state.

stringidrequired

Opaque SandBase run identifier. Use it exactly as returned; no prefix is guaranteed.

stringstatusrequired

Current public run status.

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

Optional<string>model

Public SandBase model name used for this run.

Optional<array<object>>outputs

Present only for completed runs. Each object is capability-specific; inspect the selected model schema for its fields.

Optional<object>error

Present only for failed or timeout runs. Contains a public error type and sanitized message.

Optional<string>error.type

Stable public error category.

Optional<string>error.message

Sanitized error message safe to show to clients.

Optional<object>usage

Usage details when available.

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": "alibaba/happy-horse/1.1/reference-to-video",
  "prompt": "A dance battle between character1 and character2, cinematic lighting, smooth camera movement.",
  "duration": 5,
  "aspect_ratio": "21:9"
}'

# 2. If the response is still running, poll the returned id
curl https://api.sandbase.ai/v1/run/f3d2e8a1-7c4b-4a12-9d2e-123456789abc \
  -H "Authorization: Bearer $SANDBASE_API_KEY"

Response202 Accepted

{
  "id": "f3d2e8a1-7c4b-4a12-9d2e-123456789abc",
  "model": "alibaba/happy-horse/1.1/reference-to-video",
  "status": "running"
}