# Heygen v5 Digital Twin API

> Avatar V digital twin with 4k output, transparent WebM, background, watermark and SRT captions

Creates a speaking avatar video from text (`prompt` and `voice`) or from an `audio_url` for lip-sync. Select a named `avatar`, a `fit` mode of contain or cover, and a resolution of 720p, 1080p or 4k. `output_format` can be mp4 or webm; webm is transparent. Options include background compositing, a watermark overlay and a sidecar SRT caption file.

- Model id: `heygen/avatar5/digital-twin`
- Made by: HeyGen
- Category: Lipsync & Avatars
- Output: video
- Price per second of your input audio: $0.10 / second of input audio (cheapest run $0.10 (100 API credits))
- Run: `POST https://api.doitong.com/v1/run/heygen/avatar5/digital-twin`
- Quote: `POST https://api.doitong.com/v1/quote/heygen/avatar5/digital-twin`
- Docs page: https://doitong.com/developers/models/heygen/avatar5/digital-twin

## Pricing

Price: **$0.10 / second of input audio**. Price per second of your input audio: the input files are measured before the run (length, resolution, frame rate). The quote measures the same files and is exactly what the run charges.

The full example input below costs $1.00 = 1000 API credits (10 s input audio × $0.10).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.com/v1/quote/heygen/avatar5/digital-twin` with the same JSON body returns the exact price for that input; the quote is exactly what a run charges. Invalid input is never charged and failed or canceled requests are refunded automatically.

## Input parameters

Send either the canonical name or the native field name (not both). Canonical names are the same across models.

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `avatar` |  | string \| null | no | `Abigail Sofa Front` |  | Name identifying an avatar eligible for Avatar V. |
| `prompt` |  | string \| null | no |  |  | Speech text for the avatar; required if `audio_url` is omitted. |
| `voice` |  | enum (string) \| null | no | `Warm Pro Narrator` | `Warm Pro Narrator`, `Chill Brian`, `Ivy`, `John Doe`, `Monika Sogam`, `Hope `, `Archer `, `Brittney`, `Patrick`, `David Castlemore`, `Michael C`, `Adam Stone `, `Juniper`, `Cassidy `, `Jessica Anne Bogart`, `Arabella`, `Andrew`, `Spuds Oxley `, `Grace Elder`, `Helen`, `Canyon Rivers`, `Derya - Lifelike - Excited 🤩`, `Mellow Marcus`, `Jack Sterling - Broadcaster 🎙️`, `Brenda - UGC - 1.mp4`, `Reid`, `Reagan`, `Terry`, `Jenny`, `Radio Rick`, `Denise`, `Tim in car - Excited 🤩`, `Iskander`, `Thompson`, `Delicate Daisy - Excited 🤩`, `Kingston`, `George UGC 1`, `Bold Blake`, `Jane`, `Expressive Evan`, `Marianne - IA`, `Aaron`, `Modern Recipe Host - Voice 1`, `Willow`, `Cute Chloe - Friendly 😊`, `Rafael`, `June - Lifelike`, `Crisp Chloe`, `Slick Simon`, `Nassim - Informative`, `Baritone Ben`, `Maxwell`, `Ellie Faye - Excited 🤩`, `Milani`, `Feisty Fiona - Excited 🤩`, `Professor Dean`, `Rose - UGC - 1.mp4`, `Shona`, `Hudson Wilder`, `Ann - IA`, `Alastair Kensington`, `Oxley`, `Christina`, `Andrew Rizz `, `Peyton`, `Gerardo - Outdoor`, `Chloe - Lifelike`, `Stephanie`, `Anthony - IA`, `Signal - Voice 1`, `Luca`, `Lisa - Voice 1`, `T.W.Tucker`, `Jack Sullivan - Serious 😐`, `Winter`, `Mireia - Lifelike`, `Georgia`, `Stella`, `Masha - Lifelike`, `Charming Charles - Friendly 😊`, `Serenity`, `Annie - Excited`, `Ralph`, `Bethany`, `Dominic`, `Mason Finn`, `Leena`, `Veteran Victor`, `Tamara`, `Nik Public`, `Calm Chloe`, `Sevik`, `Reilly`, `Raul`, `Imposing Ian`, `Relaxed Ray`, `Dexter - Professional`, `Relaxed Rick`, `Edwin`, `Rupert Blackwood`, `Ginny`, `Hope` | Avatar voice selection by name for text-to-speech; it applies only without an `audio_url`. |
| `audio_url` | `audio` | string (audio URL) \| null | no |  |  | Lip-sync source supplied as an HTTP(S) audio file URL, replacing text-to-speech when present. Neither `prompt` nor `voice` is used in that case. |
| `fit` |  | enum (string) | no | `cover` | `contain`, `cover` | Choose the avatar's framing: 'cover' fills the output frame but may crop the avatar, whereas 'contain' shows the entire avatar but may add letterboxing. |
| `remove_background` |  | boolean | no | `false` |  | Background removal for the avatar; available only for avatars that support matting. |
| `background` |  | object {type, value} \| null | no |  |  | Background layer optionally placed behind the avatar, except with `output_format='webm'`: transparent webm output ignores this setting. |
| `background.type` |  | enum (string) | no | `color` | `color`, `image` | Background kind: `color` specifies a solid hexadecimal color, while `image` specifies an image URL. |
| `background.value` |  | string | no | `#FFFFFF` |  | Background content: a hexadecimal color when the type is `color`, or an HTTP(S) URL when the type is `image`. |
| `watermark` |  | object {image_url, scale, opacity, placement} \| null | no |  |  | Optional image used as a watermark overlay in the generated video. |
| `watermark.image_url` |  | string (image URL) | yes |  |  | Watermark image URL using HTTP(S), for overlaying onto the video. |
| `watermark.scale` |  | number \| null | no |  | ≤ 2, > 0 | Watermark size relative to the video, greater than 0.0 and up to 2.0. |
| `watermark.opacity` |  | number \| null | no |  | 0 – 1 | Watermark transparency level: 0.0 is fully transparent and 1.0 is fully opaque. |
| `watermark.placement` |  | enum (string) \| null | no |  | `top-left`, `top-right`, `bottom-left`, `bottom-right` | Position of the watermark within the video. |
| `caption` |  | boolean | no | `false` |  | Controls generation of a separate SRT caption file accompanying the video. |
| `output_format` |  | enum (string) | no | `mp4` | `mp4`, `webm` | Video container selection, with `webm` enabling transparency through automatic background removal; in that mode, `background` has no effect. |
| `resolution` |  | enum (string) | no | `720p` | `720p`, `1080p`, `4k` | Resolution preset for the generated output. |
| `aspect_ratio` |  | enum (string) | no | `16:9` | `16:9`, `9:16`, `4:5`, `5:4`, `1:1`, `auto` | Video aspect-ratio selection: 'auto' asks HeyGen to read and retain the source ratio, using '16:9' if it cannot. Explicit ratio choices are '16:9', '9:16', '4:5', '5:4', and '1:1'. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Screening can be relaxed by setting false, provided the caller is authorized. |

File parameters (`audio`) take a public `https://` URL, a `data:` URI up to 10 MB, or the `file_url` of an upload from `POST /files`.

## Example input

Required parameters only:

```json
{}
```

A fuller example:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
  "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
}
```

## Run it

Set `DOITONG_API_KEY` to a key from https://doitong.com/developers/dashboard#keys. `?wait=20` returns the finished request in the same call when it is ready within 20 seconds; otherwise poll `GET /requests/{id}` (it also accepts `?wait=`), or pass `webhook_url`.

### curl

```bash
# Run the model; wait up to 20 s for the finished result in the same call
curl -X POST "https://api.doitong.com/v1/run/heygen/avatar5/digital-twin?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  }'

# Still "queued" or "running"? Poll with the id from the response:
curl "https://api.doitong.com/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"
```

### JavaScript

```javascript
const API = "https://api.doitong.com/v1";
const headers = {
  "Authorization": "Bearer " + process.env.DOITONG_API_KEY,
  "Content-Type": "application/json",
};

// Run the model; wait up to 20 s for the finished result in the same call
let res = await fetch(API + "/run/heygen/avatar5/digital-twin?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  }),
});
let request = await res.json();
if (!res.ok) throw new Error(request.error.code + ": " + request.error.message);

// Not finished yet: long-poll until it is
while (request.status === "queued" || request.status === "running") {
  res = await fetch(API + "/requests/" + request.id + "?wait=20", { headers });
  request = await res.json();
}
if (request.status !== "succeeded") throw new Error(JSON.stringify(request.error));
console.log(request.outputs.map((o) => o.url), request.cost.credits + " API credits ($" + request.cost.usd + ")");
```

### Python

```python
import os
import requests

API = "https://api.doitong.com/v1"
headers = {"Authorization": "Bearer " + os.environ["DOITONG_API_KEY"]}

payload = {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/heygen/avatar5/digital-twin", params={"wait": 20}, json=payload, headers=headers)
request = r.json()
if not r.ok:
    raise RuntimeError(request["error"]["code"] + ": " + request["error"]["message"])

# Not finished yet: long-poll until it is
while request["status"] in ("queued", "running"):
    request = requests.get(API + "/requests/" + request["id"], params={"wait": 20}, headers=headers).json()
if request["status"] != "succeeded":
    raise RuntimeError(request["error"])
print([o["url"] for o in request["outputs"]], request["cost"]["credits"], "API credits", "$" + request["cost"]["usd"])
```

### MCP

The MCP server at `https://api.doitong.com/v1/mcp` exposes the tools `search_models`, `get_model`, `quote`, `run`, `get_request`, `cancel_request`, `list_requests`, `create_upload` and `get_account`. A `run` call for this model:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "run",
    "arguments": {
      "model_id": "heygen/avatar5/digital-twin",
      "input": {
        "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
        "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
      },
      "wait_seconds": 20
    }
  }
}
```

## Response

Every call returns a request object. `status` is one of `queued`, `running`, `succeeded`, `failed`, `canceled`. `outputs` lists the generated files with URLs on our storage (kept forever, or 7 days with `?storage=temporary`; `storage` says which); `output` is the model's own result object with the same URLs.

```json
{
  "id": "req_8k2m4q7x1z9c3v5b6n0p2r4t",
  "object": "request",
  "model": "heygen/avatar5/digital-twin",
  "status": "succeeded",
  "created_at": "2026-10-20T12:00:00Z",
  "started_at": "2026-10-20T12:00:02Z",
  "completed_at": "2026-10-20T12:00:09Z",
  "queue_position": null,
  "cost": {
    "credits": 1000,
    "usd": "1.00",
    "charged": 1000,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  },
  "output": {
    "video": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_name": "0-output.mp4",
      "file_size": 1843200
    },
    "caption_file": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_name": "0-output.mp4",
      "file_size": 1843200
    }
  },
  "outputs": [
    {
      "type": "video",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_size": 1843200,
      "width": 1280,
      "height": 720,
      "duration": 5,
      "stored": true
    }
  ],
  "error": null,
  "metrics": {
    "inference_seconds": 6.8
  },
  "urls": {
    "self": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `video` | object {url, content_type, file_name, file_size} | Video file produced by Avatar V. |
| `caption_file` | object {url, content_type, file_name, file_size} \| null | SRT caption file produced when `caption=True`, if the service supplies one. |

## Related models

- [Kling AI Avatar 2.0 Pro](https://doitong.com/developers/models/kling-video/ai-avatar/v2/pro.md) (`kling-video/ai-avatar/v2/pro`): $0.115 / second of input audio
- [Sync Lipsync 3](https://doitong.com/developers/models/sync-lipsync/v3.md) (`sync-lipsync/v3`): $8.00 / minute of output video
- [VEED Fabric 1.0](https://doitong.com/developers/models/veed/fabric-1.0.md) (`veed/fabric-1.0`): from $0.08 / second of input audio
- [Heygen Lipsync - Precision](https://doitong.com/developers/models/heygen/v3/lipsync/precision.md) (`heygen/v3/lipsync/precision`): $0.10 / second of output video
- [Heygen Lipsync - Speed](https://doitong.com/developers/models/heygen/v3/lipsync/speed.md) (`heygen/v3/lipsync/speed`): $0.05 / second of output video
- [Heygen · Avatar3 · Digital Twin](https://doitong.com/developers/models/heygen/avatar3/digital-twin.md) (`heygen/avatar3/digital-twin`): $0.034 / second of input audio
- [Heygen · Avatar4 · Digital Twin](https://doitong.com/developers/models/heygen/avatar4/digital-twin.md) (`heygen/avatar4/digital-twin`): $0.10 / second of input audio
- [Heygen · Avatar4 · Image to Video](https://doitong.com/developers/models/heygen/avatar4/image-to-video.md) (`heygen/avatar4/image-to-video`): $0.10 / second of input audio

## Links

- HTML page: https://doitong.com/developers/models/heygen/avatar5/digital-twin
- All models and guides for AI agents: https://doitong.com/developers/llms.txt
- OpenAPI 3.1 with this model's typed request body: https://doitong.com/developers/openapi.json?model=heygen/avatar5/digital-twin
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/heygen/avatar5/digital-twin