Alibaba Wan 3.0 Prime Video Extend API Documentation

Alibaba Wan 3.0 Prime Video Extend API Documentation

Playground

Wan 3.0 Prime Video Extend continues existing videos by generating a new 2-30 second segment from the final frame and appending it to the retained source video. It preserves existing source audio, supports optional audio generation for the new segment, retains up to the last 120 seconds of input, and outputs at 480P / 720P / 1080P. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.

Features

Wan 3.0 Prime Video Extend continues an existing video with a new AI-generated segment while preserving the visual and audio context of the source footage. Instead of regenerating the original clip, it keeps the retained source intact and generates what happens next, making it suitable for longer narrative sequences, continuous camera movement, character actions, and scene progression.

Why Choose This?

• Continuous video extension
  Continue an existing clip instead of generating an unrelated new shot, helping maintain scene, subject, and motion continuity.

• Up to 120 seconds of source context
  The model can retain and use up to the last 120 seconds of the source video before generating the continuation.

• 2–30 second new segments
  Append a newly generated segment from 2 to 30 seconds in a single request.

• Prime generation quality
  Designed for higher-quality continuation workflows where visual coherence, motion progression, and scene continuity matter.

• Optional ending-frame control
  Use last_image to guide the final appearance or composition of the newly generated segment.

• Audio-aware continuation
  Existing source audio is preserved, while enable_audio can generate audio for the newly appended segment.

• 480p, 720p, and 1080p output
  Choose the resolution that best fits preview, production, or higher-quality workflows.

• Prompt expansion
  Enable automatic prompt optimization when the continuation requires more detailed motion or scene interpretation.

Parameters

How to Use

1. Upload a source video — Provide the clip you want to continue.
2. Describe what happens next — Write a prompt focused on the continuation rather than repeating the existing scene.
3. Add last-frame guidance optional — Provide last_image when the continuation should end on a specific composition, pose, or scene state.
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 the continuation instruction needs additional interpretation.
7. Configure audio optional — Keep enable_audio enabled when the generated segment should include new 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 completed output.

Pricing

Pricing is based only on the newly generated extension duration and selected resolution. The retained source video duration is not included in the pricing calculation.

Example Costs

Best Use Cases

• Narrative continuation — Extend story scenes without restarting the sequence from scratch.
• Longer cinematic shots — Continue camera movement, character actions, and environmental motion beyond the original clip.
• Character continuity — Extend scenes where the same subject needs to remain visually consistent across the transition.
• Action progression — Continue walking, driving, dancing, combat, performance, or other ongoing motion.
• Scene evolution — Progress lighting, weather, environment, or events naturally from the existing footage.
• Start-to-end directed extension — Use last_image when the continuation needs to arrive at a specific final frame.
• Long-form AI video workflows — Build longer sequences by repeatedly extending existing generated or edited clips.

Pro Tips

• Write the prompt around what happens next, not just what is already visible in the source video.
• Mention the direction of existing movement when continuity matters, such as camera tracking, character movement, or vehicle direction.
• Keep character identity, clothing, environment, lighting, and camera behavior consistent in the prompt when the scene should remain continuous.
• Use last_image when the continuation needs to end on a specific pose, composition, object state, or environment.
• Use shorter extensions first when testing motion continuity, then increase duration once the direction is stable.
• Enable enable_prompt_expansion for short prompts that need more detailed interpretation.
• Use a fixed seed when comparing different prompts or parameter configurations.

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.
• 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 Prime Image-to-Video — Generate Prime-quality video from a first-frame image.
• 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 video using multimodal reference images, video, and audio.
• Wan 3.0 Text-to-Video — Generate video directly from natural-language prompts.

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-prime/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