LTX-2 19B API

About LTX-2 19B

LTX-2 19B is Lightricks' open audio-video foundation model, which generates a clip and its soundtrack together. Text-to-video, image-to-video and video-extend run 5 to 20 seconds at 480p, 720p or 1080p, and every MP4 carries stereo sound that follows the prompt.

Call it with the model name lightricks/ltx-2-19b/text-to-video on POST /jobs/createTask, from 11 credits for a 5-second clip ($0.11). New accounts get 30 free credits to try it in the Playground first.

Introduction

LTX-2 19B Text to video turns one prompt into a clip with its own soundtrack. LTX-2 is Lightricks' open audio-video foundation model with 19 billion parameters; this endpoint returns 5 to 20 seconds at 480p, 720p or 1080p in 16:9 or 9:16, with stereo sound in the same MP4.

Choose a mode by starting material

Key features

Picture and sound together

Voices, singing, instruments, effects and room tone are generated with the frames, so they line up with the action.

Fast at 720p

In our tests a 5-second 720p clip took 14 to 25 seconds of model time.

Request parameters

Pricing

Prices are in credits, the same credits you use on the website (1 credit = $0.01). The hold is taken when the task is accepted and settled to the actual charge when it finishes; failed tasks are refunded.

Each task is rounded up to whole credits, so one run at the lowest tier costs 11 credits for a 5-second clip ($0.11).

For an exact number before you run, send the same body to POST /jobs/quote.

Use cases

Performance clips

Singers, musicians and dancers with their sound in one file.

Longer takes

Twenty seconds is enough for a scene with a beginning and an end.

Prompt guide & pro tips

Put sound on its own line

End with "Audio:" and list what should be heard.

Speech is stronger than ambience

The publisher notes that sound without speech can be of lower quality; a voice or a song carries better.

Draft at 5 seconds

Find the shot at 5 seconds and 480p, then extend the length or the resolution.

Expect slightly short frames

720p is 1280 x 704 and 1080p is 1920 x 1024; plan crops accordingly.

API quick start

Call the LTX-2 19B API in three steps

1. Create an API key. Sign in to PopNow and create a key in the API console. Keys start with sk-popnow- and use the same credits as the website.
2. Send the request. POST /jobs/createTask with model lightricks/ltx-2-19b/text-to-video and an input object that follows the parameter table. The response returns a task ID straight away.
3. Get the result. Poll GET /jobs/recordInfo with the task ID, or pass a callBackUrl and we post the result to it. Download the output links when the task succeeds.

# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "lightricks/ltx-2-19b/text-to-video",
  "input": {
    "prompt": "A slow aerial shot drifting over a misty pine forest at sunrise",
    "aspect_ratio": "16:9",
    "resolution": "720p",
    "duration_seconds": 5
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Replace the prompt and any links with your own. The API tab has the response, polling and callback reference.

LTX-2 19B API questions

All LTX models

LTX 2.5 reaches 2K and 4K for the same 20-second length; LTX-2 19B is the cheaper, open model with clip extension.

• LTX 2.5 APILong 20-second takes up to 4K with a soundtrackFrom 68 credits for a 5-second clip
• LTX-2.3 LoRA APILTX-2.3 clips with stereo sound and your own LoRAsFrom 18 credits for a 5-second clip
• LTX-2 19B API20-second clips with voices, music and effectsFrom 11 credits for a 5-second clip
• LTX-2 19B LoRA APILTX-2 clips with sound and your own LoRA stylesFrom 14 credits for a 5-second clip

Other video APIs

• MiniMax H3 APIExpressive clips with audio, up to 2KFrom 28 credits for a 5-second clip
• Seedance 2.5 APIByteDance's newest: 30-second clips with native audioFrom 56 credits for a 5-second clip
• Kling 3.0 API4K clips, multi-shot cuts and motion controlFrom 51 credits for a 5-second clip
• Vidu Q4 Preview APIUp to 4K clips with sound and spoken dialogueFrom 34 credits for a 5-second clip
• Wan 3.0 APIUp to 30-second clips with synced audioFrom 34 credits for a 5-second clip
• Kling O3 APIKling’s unified model: create, animate, reference and edit up to 4KFrom 51 credits for a 5-second clip

More about LTX-2 19B

Try it

LTX-2 19B AI Video Generator onlineCreate videos with LTX-2 19B in PopNow

Docs

LTX-2 19B model ID and input schema in the API docsPopNow API quickstart: your first request in five minutesImage to video guide for the PopNow APIWebhooks: get LTX-2 19B results without polling