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

> Générateur vidéo Wan 2.1 qui anime la transition entre une première image et une dernière image données

Crée un clip qui passe de `start_image_url` à `end_image_url`, selon les indications d’un `prompt`. La résolution est 480p ou 720p, et le format d’image peut être auto, 16:9, 9:16 ou 1:1. `num_frames` est de 81 à 100 et `frames_per_second` de 5 à 24. Prend en charge `negative_prompt`, `seed`, les paramètres de guidage et d’étapes, ainsi que les poids LoRA via `loras`.

- Model id: `wan-flf2v`
- Made by: Alibaba
- Category: Image to Video
- Output: video
- Price: from $0.20 / video (cheapest run $0.20 (200 API credits))
- Run: `POST https://api.doitong.com/v1/run/wan-flf2v`
- Quote: `POST https://api.doitong.com/v1/quote/wan-flf2v`
- Docs page: https://doitong.com/fr-CA/developers/models/wan-flf2v

## Pricing

Price: **from $0.20 / video** (the lowest tier; the quote prices your exact input). Billed once per generated video.

Price rules (the first rule that matches the input wins; a parameter you leave out counts as its default):

- When `num_frames` > 81 and `resolution` = 720p: $0.50 (500 API credits) / video
- When `resolution` = 720p: $0.40 (400 API credits) / video
- When `num_frames` > 81: $0.25 (250 API credits) / video

The full example input below costs $0.40 = 400 API credits (1 video × 400 API credits).

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/wan-flf2v` 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 |
|---|---|---|---|---|---|---|
| `prompt` |  | string | yes |  |  | Instructions textuelles qui orientent la génération vidéo. |
| `negative_prompt` |  | string | no | `bright colors, overexposed, static, blurred details, subtitles, style, artwork, painting, picture, still, overall gray, worst quality, low quality, JPEG compression residue, ugly, incomplete, extra fingers, poorly drawn hands, poorly drawn faces, deformed, disfigured, malformed limbs, fused fingers, still picture, cluttered background, three legs, many people in the background, walking backwards` |  | Invite négative appliquée lors de la génération d’une vidéo. |
| `start_image_url` | `image` | string (image URL) | yes |  |  | Fournissez l’image de départ par URL; pour respecter le rapport hauteur-largeur sélectionné, un redimensionnement et un recadrage autour du centre sont effectués lorsque le rapport de l’image diffère. |
| `end_image_url` | `end_image` | string (image URL) | yes |  |  | Fournissez l’image de fin par URL; pour respecter le rapport hauteur-largeur sélectionné, un redimensionnement et un recadrage autour du centre sont effectués lorsque le rapport de l’image diffère. |
| `num_frames` |  | integer \| null | no | `81` | 81 – 100 | Nombre d’images pour la génération, de 81 à 100 inclusivement. |
| `frames_per_second` |  | integer \| null | no | `16` | 5 – 24 | Cadence de la vidéo générée, en images par seconde, de 5 à 24. |
| `seed` |  | integer \| null | no |  |  | Graine qui rend la génération reproductible. La définir sur None sélectionne une graine aléatoirement. |
| `resolution` |  | enum (string) | no | `720p` | `480p`, `720p` | Résolution vidéo de sortie, soit 480p, soit 720p. |
| `num_inference_steps` |  | integer | no | `30` | 2 – 40 | Nombre d’étapes d’échantillonnage, qui privilégie une durée de traitement plus longue pour une meilleure qualité lorsque le nombre augmente. |
| `guide_scale` |  | number | no | `5` | 1 – 10 | Intensité du guidage sans classifieur, qui échange une éventuelle perte de qualité contre une meilleure correspondance avec l’invite lorsque l’échelle augmente. |
| `shift` |  | number | no | `5` | 1 – 10 | Paramètre de décalage appliqué lors de la génération de la vidéo. |
| `enable_safety_checker` |  | boolean | no | `false` |  | Commutateur de vérification de sécurité dont la désactivation exige l’autorisation du compte. Sans cette autorisation, chaque requête est vérifiée quel que soit le réglage; true active le vérificateur. |
| `enable_prompt_expansion` |  | boolean | no | `false` |  | Contrôle l’activation de l’expansion de l’invite. |
| `acceleration` |  | enum (string) | no | `regular` | `none`, `regular` | Paramètre d’accélération, avec 'regular' comme choix recommandé. Une accélération accrue réduit la qualité pour raccourcir le temps de génération. |
| `aspect_ratio` |  | enum (string) | no | `auto` | `auto`, `16:9`, `9:16`, `1:1` | Proportions de la vidéo générée, sélectionnées automatiquement à partir de l’image d’entrée lorsque la valeur est 'auto'. |
| `loras` |  | array of object {path, weight_name, scale} | no | `[]` |  | Poids LoRA appliqués pendant l’inférence. |
| `loras[].path` |  | string | yes |  |  | Emplacement des poids LoRA, indiqué par une URL ou un chemin. |
| `loras[].weight_name` |  | string \| null | no |  |  | Nom du poids LoRA, requis uniquement lorsqu’un dépôt Hugging Face contient plus d’un fichier safetensors. Ce nom est utilisé uniquement lorsque `path` identifie un tel dépôt. |
| `loras[].scale` |  | number | no | `1` | 0 – 4 | Multiplicateur appliqué au poids LoRA avant sa fusion avec le modèle de base. |

File parameters (`image`, `end_image`) 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
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
  "image": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
  "end_image": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
}
```

A fuller example:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
  "start_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
  "end_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
}
```

## 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/wan-flf2v?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",
    "start_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    "end_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
  }'

# 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/wan-flf2v?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",
    "start_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    "end_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
  }),
});
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",
    "start_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    "end_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/wan-flf2v", 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": "wan-flf2v",
      "input": {
        "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
        "start_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
        "end_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
      },
      "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": "wan-flf2v",
  "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": 400,
    "usd": "0.40",
    "charged": 400,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "start_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
    "end_image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
  },
  "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
    },
    "seed": 42
  },
  "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} | Fichier vidéo produit par la génération. |
| `seed` | integer | Valeur de graine appliquée pendant la génération. |

## Related models

- [Wan-2.1 Pro Text-to-Video](https://doitong.com/developers/models/wan-pro/text-to-video.md) (`wan-pro/text-to-video`): $0.80 / run
- [Wan-2.1 Text-to-Video](https://doitong.com/developers/models/wan-t2v.md) (`wan-t2v`): from $0.20 / video
- [Wan Effects](https://doitong.com/developers/models/wan-effects.md) (`wan-effects`): $0.35 / video
- [Wan-2.1 Image-to-Video](https://doitong.com/developers/models/wan-i2v.md) (`wan-i2v`): from $0.20 / video
- [Wan-2.1 Pro Image-to-Video](https://doitong.com/developers/models/wan-pro/image-to-video.md) (`wan-pro/image-to-video`): $0.80 / video
- [Wan 3.0 Image to Video](https://doitong.com/developers/models/alibaba/wan-3.0/image-to-video.md) (`alibaba/wan-3.0/image-to-video`): from $0.05 / second
- [FLUX 3 Max Image to Video](https://doitong.com/developers/models/blackforestlabs/flux-3-max/image-to-video.md) (`blackforestlabs/flux-3-max/image-to-video`): from $0.0425 / second of output video
- [Grok Imagine Video 1.5 Image to Video](https://doitong.com/developers/models/xai/grok-imagine-video/v1.5/image-to-video.md) (`xai/grok-imagine-video/v1.5/image-to-video`): from $0.082 / second

## Links

- HTML page: https://doitong.com/developers/models/wan-flf2v
- 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=wan-flf2v
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/wan-flf2v