Wan-2.1 First-Last-Frame-to-Video API Reference

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/wan/2.1/flf-to-video.

Default: alibaba/wan/2.1/flf-to-video

stringpromptrequired

The text prompt to guide video generation.

stringimagerequired

URL of the starting image. If the input image does not match the chosen aspect ratio, it is resized and center cropped.

Optional<string>end_image

URL of the ending image. If the input image does not match the chosen aspect ratio, it is resized and center cropped.

Optional<string>resolution

Resolution of the generated video (480p or 720p). 480p is 0.5 billing units, and 720p is 1 billing unit.

Allowed values: 480p, 720p

Default: 720p

Optional<number>guide_scale

Classifier-free guidance scale. Higher values give better adherence to the prompt but may decrease quality.

Range: 1 to 10

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. If None, a random seed is chosen.

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/wan/2.1/flf-to-video", "prompt": "A tabby cat is confidely strolling toward the camera, when it spins and with a flash of magic reveals itself to be a cat-dragon hybrid with glistening amber scales.", "image": "https://static.sandbase.ai/examples/alibaba/wan/2.1/flf-to-video/input_image_0.png", "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"