Alicloud AI Video Wan Video

Category: provider

Model Studio Wan Video

Provide consistent video generation behavior for the video-agent pipeline by standardizing video.generate inputs/outputs and using DashScope SDK (Python) with the exact model name.

Critical model name

Use ONLY this exact model string:

• wan2.6-i2v-flash

Do not add date suffixes or aliases.

Prerequisites

• Install SDK (recommended in a venv to avoid PEP 668 limits):

python3 -m venv .venv
. .venv/bin/activate
python -m pip install dashscope

• Set DASHSCOPE_API_KEY in your environment, or add dashscope_api_key to ~/.alibabacloud/credentials (env takes precedence).

Normalized interface (video.generate)

Request

• prompt (string, required)
• negative_prompt (string, optional)
• duration (number, required) seconds
• fps (number, required)
• size (string, required) e.g. 1280*720
• seed (int, optional)
• reference_image (string | bytes, required for wan2.6-i2v-flash)
• motion_strength (number, optional)

Response

• video_url (string)
• duration (number)
• fps (number)
• seed (int)

Quick start (Python + DashScope SDK)

Video generation is usually asynchronous. Expect a task ID and poll until completion. Note: wan2.6-i2v-flash requires an input image; map reference_image to img_url.

import os
from dashscope import VideoSynthesis

# Prefer env var for auth: export DASHSCOPE_API_KEY=...
# Or use ~/.alibabacloud/credentials with dashscope_api_key under [default].

def generate_video(req: dict) -> dict:
    payload = {
        "model": "wan2.6-i2v-flash",
        "prompt": req["prompt"],
        "negative_prompt": req.get("negative_prompt"),
        "duration": req.get("duration", 4),
        "fps": req.get("fps", 24),
        "size": req.get("size", "1280*720"),
        "seed": req.get("seed"),
        "motion_strength": req.get("motion_strength"),
        "api_key": os.getenv("DASHSCOPE_API_KEY"),
    }

    if req.get("reference_image"):
        # DashScope expects img_url for i2v models; local files are auto-uploaded.
        payload["img_url"] = req["reference_image"]

    response = VideoSynthesis.call(**payload)

    # Some SDK versions require polling for the final result.
    # If a task_id is returned, poll until status is SUCCEEDED.
    result = response.output.get("results", [None])[0]

    return {
        "video_url": None if not result else result.get("url"),
        "duration": response.output.get("duration"),
        "fps": response.output.get("fps"),
        "seed": response.output.get("seed"),
    }

Async handling (polling)

import os
from dashscope import VideoSynthesis

task = VideoSynthesis.async_call(
    model="wan2.6-i2v-flash",
    prompt=req["prompt"],
    img_url=req["reference_image"],
    duration=req.get("duration", 4),
    fps=req.get("fps", 24),
    size=req.get("size", "1280*720"),
    api_key=os.getenv("DASHSCOPE_API_KEY"),
)

final = VideoSynthesis.wait(task)
video_url = final.output.get("video_url")

Operational guidance

• Video generation can take minutes; expose progress and allow cancel/retry.
• Cache by (prompt, negative_prompt, duration, fps, size, seed, reference_image hash, motion_strength).
• Store video assets in object storage and persist only URLs in metadata.
• reference_image can be a URL or local path; the SDK auto-uploads local files.
• If you get Field required: input.img_url, the reference image is missing or not mapped.

Size notes

• Use WxH format (e.g. 1280*720).
• Prefer common sizes; unsupported sizes can return 400.

Output location

• Default output: output/ai-video-wan-video/videos/
• Override base dir with OUTPUT_DIR.

Anti-patterns

• Do not invent model names or aliases; use wan2.6-i2v-flash only.
• Do not block the UI without progress updates.
• Do not retry blindly on 4xx; handle validation failures explicitly.

References

• See references/api_reference.md for DashScope SDK mapping and async handling notes.

• Source list: references/sources.md