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Lip-sync API

Text or audio in. A talking video out. One call.

The dialogue endpoint chains speech and lip-sync for you: send a face and a script, or a face and an audio file. 12 lip-sync and avatar models, at base model cost plus a flat 20% platform fee, shown before you spend.

  • 12 lip-sync and avatar models
  • Text or audio input
  • Quote before you run
  • No plan

A talking video is usually two vendors and a glue script.

The usual setup
  • A text-to-speech vendor for the voice
  • A separate avatar or lip-sync vendor for the face
  • Your own code to pass audio from one to the other, and two bills
  • Avatar tools sold on monthly plans priced in minutes or credits
On FairStack
  • One call: text, voice and face in, video out
  • Or bring your own audio file and skip the speech step
  • One quote covers both legs before anything runs
  • Speech, lip-sync and everything else on one balance

What you can build

Talking product explainers

A presenter that reads your script in any of 168 library voices.

Localized video

Dub the audio, then lip-sync the face to the new language.

Character dialogue

Multiple speakers in one request for short scenes.

Bring your own audio

Pass an audio URL and the model lip-syncs the face to it.

Lip-sync existing video

Re-sync a video to new audio. Kling LipSync is $0.0168/s.

Pick the model per call

Trade speed, length and fidelity per request.

Compare models →

One request, both legs

estimate: true returns the price of the speech and the lip-sync together. Remove it to run.

curl -X POST https://api.fairstack.ai/v1/dialogue/generate \
  -H "Authorization: Bearer $FAIRSTACK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "text": "Welcome back. Here is what changed this week.",
    "character_image_url": "https://example.com/presenter.png",
    "talking_head_model": "infinitetalk",
    "resolution": "480p",
    "estimate": true
  }'

Lip-sync and avatar prices

Live catalog prices. Per-second models are billed on the length of the output.

Live catalog prices: base model cost plus a flat 20% platform fee. Every call is priced before it runs. All models

How it runs

  1. 01
    Quote

    Send the request with estimate set to true. You get the speech cost, the lip-sync cost and the total.

  2. 02
    Run

    Drop estimate. The call answers in milliseconds with a job id and runs both legs in the background.

  3. 03
    Collect

    Poll the job or take a webhook. You get the video URL and the final cost of each leg.

Frequently asked questions

Can I send my own audio instead of text? +

Yes. Pass audio_url and the speech step is skipped. The face is lip-synced to your audio.

What does a talking video cost? +

It depends on the model and the length. InfiniteTalk is $0.30 per generation (480p). A text request also pays for the speech it generates. Every price is base model cost plus a flat 20% platform fee, shown before you spend.

Is it synchronous? +

No. The call validates your input and answers with a job id straight away, then runs in the background. Poll the job, or pass wait to block until the video is ready.

Do I need a plan? +

No. FairStack has no plans. Add funds to one balance, $1 minimum, and pay per generation. Your balance never expires.

Still have questions? We're here to help.