Alibaba Wan 3.0 Video Extend API Documentation

Alibaba Wan 3.0 Video Extend API Documentation

Playground

Wan 3.0 Video Extend continues an existing video with a newly generated segment, preserving the source video and its original audio while supporting optional audio generation for the extension. It supports 480P / 720P / 1080P output, optional last-frame guidance, and prompt control for the next action and camera movement. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.

Features

Wan 3.0 Video Extend extends an existing video with a newly generated continuation. Provide a source video and a text prompt describing what should happen next, then choose the extension duration and output resolution.

Why Choose This?

• Video continuation
  Extend an existing video with a newly generated segment.

• Prompt-guided progression
  Describe how the scene, subject, motion, camera movement, and environment should continue.

• Optional last-frame guidance
  Use last_image to guide the final frame of the newly generated segment.

• 2–30 second extension
  Append a new segment from 2 to 30 seconds long.

• 480p, 720p, and 1080p output
  Choose the resolution that fits your quality and cost requirements.

• Audio continuation
  Preserve existing source audio and optionally generate audio for the new segment.

Parameters

How to Use

1. Upload a source video — Provide the video you want to continue.
2. Write a continuation prompt — Describe what should happen after the existing footage ends.
3. Add last-frame guidance optional — Use last_image when the final frame of the extension needs stronger control.
4. Choose resolution — Select 480p, 720p, or 1080p.
5. Set extension duration — Choose how many new seconds to append, from 2 to 30.
6. Configure prompt expansion optional — Enable enable_prompt_expansion when you want the prompt optimized automatically.
7. Configure audio optional — Keep enable_audio enabled when the newly generated segment should include generated audio.
8. Set seed optional — Use a fixed seed for reproducible generation, or -1 for random generation.
9. Submit — Generate the extended video and retrieve the output.

Pricing

Pricing is based only on the newly generated extension duration and selected resolution.

The source video duration is not included in the pricing calculation.

Billed extension duration is rounded up to the next whole second and limited to the 2–30s range.

Example Costs

Best Use Cases

• Video continuation — Extend an existing clip while continuing its scene and motion.
• Narrative extension — Continue a story, action, or character sequence beyond the original ending.
• Longer creative sequences — Build longer videos by progressively extending shorter clips.
• Scene progression — Continue camera movement, environmental motion, or subject actions.
• Last-frame-controlled extension — Use last_image to guide how the newly generated continuation should end.
• Social and marketing content — Extend short clips into longer promotional or narrative videos.

Pro Tips

• Describe what should happen after the existing video ends, rather than restating only what is already visible.
• Keep subject identity, direction of movement, camera motion, and environment consistent in the prompt when continuity matters.
• Use last_image when the extension needs to arrive at a specific final composition or scene state.
• Use shorter extensions while testing continuation direction, then increase duration after the motion is working well.
• Use 480p for lower-cost testing before generating higher-resolution results.
• Enable enable_prompt_expansion when the continuation instruction is short or needs additional detail.
• Set a fixed seed when comparing prompts or parameter changes.

Notes

• video and prompt are required.
• duration controls only the length of the newly generated segment.
• Extension duration supports 2–30 seconds and defaults to 5.
• Source videos longer than 120 seconds are automatically trimmed to their last 120 seconds.
• The retained source video duration does not affect the generation price.
• Existing source audio is preserved.
• enable_audio controls audio generation for the new segment and defaults to true.
• enable_prompt_expansion defaults to false.

Related Models

• Wan 3.0 Text-to-Video — Generate videos directly from natural-language prompts.
• Wan 3.0 Image-to-Video — Generate video from a first-frame image with optional last-frame guidance.
• Wan 3.0 Reference-to-Video — Generate videos using multimodal reference images, videos, or audio.

Authentication

For authentication details, please refer to the Authentication Guide.

API Endpoints

Submit Task & Query Result

set -euo pipefail

export WAVESPEED_API_KEY="your-api-key"

REQUEST_BODY=$(cat <<'JSON'
{
  "prompt": "A cinematic ocean wave at sunrise, highly detailed",
  "video": "https://interactive-examples.mdn.mozilla.net/media/cc0-videos/flower.mp4",
  "resolution": "720p",
  "duration": 5,
  "enable_prompt_expansion": false,
  "enable_audio": true
}
JSON
)

# 1. Submit the prediction.
SUBMIT_RESPONSE=$(curl --silent --show-error --fail-with-body \
  -X POST "https://api.wavespeed.ai/api/v3/alibaba/wan-3.0/video-extend" \
  -H "Authorization: Bearer ${WAVESPEED_API_KEY}" \
  -H "Content-Type: application/json" \
  -d "${REQUEST_BODY}")

TASK=$(printf '%s' "${SUBMIT_RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
PREDICTION_ID=$(printf '%s' "${TASK}" | jq -r '.id // empty')
if [ -z "${PREDICTION_ID}" ]; then
  printf 'Submission response did not contain a prediction id
' >&2
  exit 1
fi
RESULT_URL="https://api.wavespeed.ai/api/v3/predictions/${PREDICTION_ID}/result"

# 2. Poll until the prediction finishes.
while true; do
  RESPONSE=$(curl --silent --show-error --fail-with-body \
    "${RESULT_URL}" \
    -H "Authorization: Bearer ${WAVESPEED_API_KEY}")
  RESULT=$(printf '%s' "${RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
  STATUS=$(printf '%s' "${RESULT}" | jq -r '.status // empty')

  case "${STATUS}" in
    completed) printf '%s\n' "${RESULT}" | jq '.outputs'; break ;;
    failed|cancelled|timeout|deleted) printf '%s\n' "${RESULT}" | jq . >&2; exit 1 ;;
    *) sleep 2 ;;
  esac
done

Parameters

Task Submission Parameters

Request Parameters

Response Parameters

Result Request Parameters

Result Response Parameters