API reference · HeyGen

heygen/heygen-avatar4/image-to-video

Integrate this model through SandBase's unified API, with production-ready schemas and examples.

VIDEOAsyncOpen model

Production endpoint

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OpenAI-compatible endpoint with unified authentication and usage tracking.

POSThttps://api.sandbase.ai/v1/run

Model IDheygen/heygen-avatar4/image-to-video

Input Schema

7 parameters · 1 required · 6 optional

Parameter	Type	Required	Description
`image`	string	Required	URL of the image to animate. The image should contain a clear face.
`audio`	string	Optional	URL of an audio file for the avatar to lip-sync to. When provided, overrides prompt and voice.
`voice`	string	Optional	The voice ID to use for the avatar. · Default: "Melissa"
`prompt`	string	Optional	The text the avatar will speak
`resolution`	string	Optional	Video resolution preset. · Options: 360p, 480p, 540p, 720p, 1080p · Default: "720p" 360p480p540p720p1080p
`aspect_ratio`	string	Optional	Aspect ratio of the output video. 'auto' preserves the source aspect ratio when available. · Options: 16:9, 9:16, 4:5, 5:4, 1:1, auto · Default: "16:9" 16:99:164:55:41:1auto
`talking_style`	string	Optional	Talking style: 'stable' for minimal movement, 'expressive' for more animation. · Options: stable, expressive · Default: "stable" stableexpressive

Output Schema

Field	Type	Description
`id`	string	Unique identifier for the generation task
`status`	string	Task status: pending, running, completed, failed, timeout
`model`	string	Model used for the generation
`outputs`	array	Array of output items
`outputs[].url`	string	URL of the generated artifact
`outputs[].content_type`	string	MIME type (e.g. image/png, video/mp4)
`error`	object \| null	Error details if failed, null on success
`error.type`	string	Machine-readable error type code
`error.message`	string	Human-readable error description

Async Workflow

This model uses asynchronous execution. Submit a request and poll for the result.

Submit — POST to /v1/run, receive an id
Poll — GET /v1/run/{id} until status is completed, failed, or timeout
Retrieve — Read outputs from the completed response

Code Examples

Ready-to-run snippets

const apiKey = process.env.SANDBASE_API_KEY;
const response = await fetch("https://api.sandbase.ai/v1/run", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${apiKey}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "heygen/heygen-avatar4/image-to-video",
    "image": "https://v3b.fal.media/files/b/0a90062c/A7EIviZqNxZ2HAs0yHeZ6_77a05b99-8588-4ffc-90aa-be7f9d34e9d3.png",
    "voice": "Melissa",
    "prompt": "Hey friends! Welcome to the GPU force podcast and today we are going to discuss about the rising GPU cost!",
    "resolution": "720p",
    "aspect_ratio": "16:9",
    "talking_style": "stable"
  }),
});

if (!response.ok) throw new Error(await response.text());
let result = await response.json();
for (let attempt = 0; attempt < 120 && !["completed", "failed", "timeout"].includes(result.status); attempt++) {
  await new Promise((resolve) => setTimeout(resolve, 2_000));
  const poll = await fetch(`https://api.sandbase.ai/v1/run/${result.id}`, {
    headers: { Authorization: `Bearer ${apiKey}` },
  });
  if (!poll.ok) throw new Error(await poll.text());
  result = await poll.json();
}
if (result.status !== "completed") throw new Error(`Generation ended: ${result.status}`);
console.log(result);

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