How to Use the VT Lip Sync API: video to video integration guide (2026)
Learn how to call the VT Lip Sync API on NamiFusion: parameters, pricing (from ≈$0.200) and runnable copy-paste code — try it in the playground first.
VT Lip Sync is a video to video model by NamiFusion: VT Lip Sync synchronizes mouth movements for a translated video by using the translated target video, translated audio, translated subtitle timing, and the original source video with its original subtitle timing. On NamiFusion you can try it in the playground (exact quote shown before you submit), then call it through one unified REST API — a typical run costs about $0.200.
TL;DR
· Task type: video to video, provided by NamiFusion
· Pricing: about $0.200 per typical run ($1 = 100 credits), pay-as-you-go
· Getting started: playground (exact quote before submit) → create an API key → one POST request
· Tunable parameters: 4 (see the table below)
· No platform watermark; commercial use allowed (per the Terms of Service)
What can you build with VT Lip Sync?
Short-form video and ad clips: go from a prompt or a single image to publishable motion content.
Product demos and concept previews: validate storyboards and visual direction cheaply before any shoot.
A social content factory: batch vertical clips and ride trending topics fast.
Remixing existing assets: image-to-video brings static work to life and extends its lifespan.
How do you call this API?
1. Sign up on NamiFusion and create a key on the API Keys page (free credits on signup).
2. Submit a task with the cURL example below, passing your key as a Bearer token.
3. Poll the task status with the returned task_uuid and read the output URLs when completed.
# 1) Submit — returns { "task_uuid": "..." }
curl -X POST "https://www.namifusion.com/api/v1/marketplace/run/namifusion/vt-lipsync" \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"input": {
"audio_url": "https://d5v2vcqcwe9y5.cloudfront.net/algorithm/video_translate/260327/default/qtqfcgymg08o.wav",
"subs_list": [
{
"end_ms": 4178,
"start_ms": 300
}
],
"original_video_url": "https://d5v2vcqcwe9y5.cloudfront.net/video_translate/260327/6964a3741d6212ca41d15d2d/3ftvqu8aewix.mp4",
"original_subs_list": [
{
"end_ms": 3780,
"start_ms": 300
}
]
}
}'
# 2) Poll until status is "completed", then read the output URLs
curl "https://www.namifusion.com/api/v1/marketplace/run/tasks/TASK_UUID" \
-H "Authorization: Bearer YOUR_API_KEY"What parameters does it take?
audio_url (Translated Audio): required
subs_list (Translated Subtitle Segments): required, default []
original_video_url (Original Video): required
original_subs_list (Original Subtitle Segments): required, default []
How much does it cost?
Pay-per-use in credits. A typical run costs about $0.200 ($1 = 100 credits); the exact price varies with parameters like resolution or duration, and the playground shows the exact quote before you submit.
VT Lip Sync
Lip-sync for translated videos: input a translated video, translated audio, and sentence-level timelines for both sides, then output a lip-synced result video.
NamiFusion VT LipSync is a lip-sync service designed for video translation scenarios. It is suitable for cases where the duration and rhythm of a video change after translation. By providing the translated video, translated audio, and two sets of sentence-level timing segments for the original and translated content, it generates a lip-synced video aligned with the target audio.
Key Features
- Built for video translation workflows: Specifically handles lip-sync drift caused by changes in audio and video length after translation.
- Dual timeline input: Accepts both translated sentence-level timelines and original sentence-level timelines to establish sentence-to-sentence alignment.
- Async Tasks: Returns a
task_uuidafter submission, and you can retrieve results through polling or Webhook. - Result video output: Returns the lip-synced video URL when the task is completed.
Technical Specifications
| Parameter | Details |
|---|---|
| Model ID | namifusion/vt-lipsync |
| Request Method | Async POST (submit task + poll/Webhook for results) |
| Input | Translated video URL + translated audio URL + dual sentence-level timelines |
| Output | Lip-synced video URL |
| Processing Time | Typically tens of seconds to several minutes, depending on video duration and number of sentence segments |
Quick Start
API Endpoints
| Endpoint | Method | Description |
|---|---|---|
/api/v1/marketplace/run/namifusion/vt-lipsync | POST | Submit a VT LipSync task |
/api/v1/marketplace/run/tasks/{task_uuid} | GET | Query task status and results |
Authentication
Include your API Key in the request header:
X-API-Key: sk-your-api-key
FAQ
Can I try it for free first?+
Signup gives you free credits, but they currently apply only to selected in-app face-swap features — this model is pay-as-you-go. The playground still lets you try it without code, with the exact quote shown before you submit.
Can I use the output commercially? Is there a watermark?+
Yes, outputs are yours to use commercially, and NamiFusion adds no platform watermark — subject to the Terms of Service and applicable law.
What is the content policy?+
NamiFusion is an unfiltered engine: no arbitrary restrictions and NSFW-friendly, but illegal content and non-consensual use of real people are prohibited — see the Terms of Service.
How long does a VT Lip Sync task take?+
It depends on parameters — images usually take seconds, videos tens of seconds to minutes. The API returns a task_uuid for polling.
What are the resolution and duration limits?+
See the parameter table above — each model lists its available resolution and duration options there and in the playground.