Longcat Multi Avatar

POST/v1/run

Longcat Multi Avatar Image Audio To Video by meituan - advanced AI model for audio-to-video. Delivers high-quality results with fast inference, suitable for both creative and production workflows.

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 meituan/longcat-multi-avatar/image-audio-to-video.

Default: meituan/longcat-multi-avatar/image-audio-to-video

stringpromptrequired

The prompt to guide the video generation.

Default: Two people are having a conversation with natural expressions and movements.

stringimagerequired

The URL of the image containing two speakers.

Optional<string>resolution

Resolution of the generated video (480p or 720p). Billing is per video-second (16 frames): 480p is 1 unit per second and 720p is 4 units per second.

Allowed values: 480p, 720p

Default: 480p

Optional<integer>num_inference_steps

The number of inference steps to use.

Range: 10 to 100

Default: 30

Optional<string>audio_url_person2

The URL of the audio file for person 2 (right side).

Default: https://raw.githubusercontent.com/meituan-longcat/LongCat-Video/refs/heads/main/assets/avatar/multi/sing_woman.WAV

Optional<integer>num_segments

Number of video segments to generate. Each segment adds ~5 seconds of video. First segment is ~5.8s, additional segments are 5s each.

Range: 1 to 10

Default: 1

Optional<string>audio_url_person1

The URL of the audio file for person 1 (left side).

Default: https://raw.githubusercontent.com/meituan-longcat/LongCat-Video/refs/heads/main/assets/avatar/multi/sing_man.WAV

Optional<string>audio_type

How to combine the two audio tracks. 'para' (parallel) plays both simultaneously, 'add' (sequential) plays person 1 first then person 2.

Allowed values: para, add

Default: para

Optional<string>bbox_person2

Bounding box for person 2. If not provided, defaults to right half of image.

Optional<number>audio_guidance_scale

The audio guidance scale. Higher values may lead to exaggerated mouth movements.

Range: 1 to 10

Default: 4

Optional<string>bbox_person1

Bounding box for person 1. If not provided, defaults to left half of image.

Optional<number>text_guidance_scale

The text guidance scale for classifier-free guidance.

Range: 1 to 10

Default: 4

Optional<integer>seed

The seed for the random number generator.

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: audio-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": "meituan/longcat-multi-avatar/image-audio-to-video",
  "prompt": "Two people are having a conversation with natural expressions and movements.",
  "image": "https://raw.githubusercontent.com/meituan-longcat/LongCat-Video/refs/heads/main/assets/avatar/multi/sing.png"
}'

# 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": "meituan/longcat-multi-avatar/image-audio-to-video",
  "status": "running",
  "outputs": []
}