PixVerse Extend Fast

POST/v1/run

Extend Fast is PixVerse's video-to-video AI model. Transform, enhance, and edit video content using text prompts - from style changes to object manipulation and scene modification.

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 pixverse/extend/fast.

Default: pixverse/extend/fast

stringpromptrequired

Prompt describing how to extend the video

Optional<string>video

URL of the input video to extend

Optional<string>resolution

The resolution of the generated video. Fast mode doesn't support 1080p

Allowed values: 360p, 540p, 720p

Default: 720p

Optional<integer>seed

Random seed for generation

Optional<boolean>generate_audio_switch

Enable audio generation (BGM, SFX, dialogue). Supported in v5.6+ models.

Default: false

Optional<string>model

The model version to use for generation

Allowed values: v3.5, v4, v4.5, v5, v5.5, v5.6, v6

Default: v4.5

Optional<string>style

The style of the extended video

Allowed values: anime, 3d_animation, clay, comic, cyberpunk

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: video-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": "pixverse/extend/fast",
  "prompt": "A kid is talking into camera",
  "video": "https://static.sandbase.ai/examples/pixverse/extend/fast/output_url_0.mp4"
}'

# 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": "pixverse/extend/fast",
  "status": "running",
  "outputs": []
}