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LTX Video (preview) Text to Video

fal-ai/ltx-video
Generate videos from prompts using LTX Video
Inference
Research only
PlaygroundAPI

About

LTX Video - Text to Video generation

See examples for more inspiration.

Instructions

When writing prompts, focus on detailed, chronological descriptions of actions and scenes. Include specific movements, appearances, camera angles, and environmental details - all in a single flowing paragraph. Start directly with the action, and keep descriptions literal and precise. Think like a cinematographer describing a shot list. Keep within 200 words. For best results, build your prompts using this structure:

  • Start with main action in a single sentence
  • Add specific details about movements and gestures
  • Describe character/object appearances precisely
  • Include background and environment details
  • Specify camera angles and movements
  • Describe lighting and colors
  • Note any changes or sudden events

Parameter Guide

  • Guidance Scale: Higher values (5-7) for accurate prompt following, lower values (3-5) for more creative freedom
  • Inference Steps: More steps (40+) for quality, fewer steps (20-30) for speed

1. Calling the API#

Install the client#

The client provides a convenient way to interact with the model API.

npm install --save @fal-ai/client

Setup your API Key#

Set FAL_KEY as an environment variable in your runtime.

export FAL_KEY="YOUR_API_KEY"

Submit a request#

The client API handles the API submit protocol. It will handle the request status updates and return the result when the request is completed.

import { fal } from "@fal-ai/client";

const result = await fal.subscribe("fal-ai/ltx-video", {
  input: {
    prompt: "A man stands waist-deep in a crystal-clear mountain pool, his back turned to a massive, thundering waterfall that cascades down jagged cliffs behind him. He wears a dark blue swimming shorts and his muscular back glistens with water droplets. The camera moves in a dynamic circular motion around him, starting from his right side and sweeping left, maintaining a slightly low angle that emphasizes the towering height of the waterfall. As the camera moves, the man slowly turns his head to follow its movement, his expression one of awe as he gazes up at the natural wonder. The waterfall creates a misty atmosphere, with sunlight filtering through the spray to create rainbow refractions. The water churns and ripples around him, reflecting the dramatic landscape. The handheld camera movement adds a subtle shake that enhances the raw, untamed energy of the scene. The lighting is natural and bright, with the sun positioned behind the waterfall, creating a backlit effect that silhouettes the falling water and illuminates the mist."
  },
  logs: true,
  onQueueUpdate: (update) => {
    if (update.status === "IN_PROGRESS") {
      update.logs.map((log) => log.message).forEach(console.log);
    }
  },
});
console.log(result.data);
console.log(result.requestId);

2. Authentication#

The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.

API Key#

In case your app is running in an environment where you cannot set environment variables, you can set the API Key manually as a client configuration.
import { fal } from "@fal-ai/client";

fal.config({
  credentials: "YOUR_FAL_KEY"
});

3. Queue#

Submit a request#

The client API provides a convenient way to submit requests to the model.

import { fal } from "@fal-ai/client";

const { request_id } = await fal.queue.submit("fal-ai/ltx-video", {
  input: {
    prompt: "A man stands waist-deep in a crystal-clear mountain pool, his back turned to a massive, thundering waterfall that cascades down jagged cliffs behind him. He wears a dark blue swimming shorts and his muscular back glistens with water droplets. The camera moves in a dynamic circular motion around him, starting from his right side and sweeping left, maintaining a slightly low angle that emphasizes the towering height of the waterfall. As the camera moves, the man slowly turns his head to follow its movement, his expression one of awe as he gazes up at the natural wonder. The waterfall creates a misty atmosphere, with sunlight filtering through the spray to create rainbow refractions. The water churns and ripples around him, reflecting the dramatic landscape. The handheld camera movement adds a subtle shake that enhances the raw, untamed energy of the scene. The lighting is natural and bright, with the sun positioned behind the waterfall, creating a backlit effect that silhouettes the falling water and illuminates the mist."
  },
  webhookUrl: "https://optional.webhook.url/for/results",
});

Fetch request status#

You can fetch the status of a request to check if it is completed or still in progress.

import { fal } from "@fal-ai/client";

const status = await fal.queue.status("fal-ai/ltx-video", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
  logs: true,
});

Get the result#

Once the request is completed, you can fetch the result. See the Output Schema for the expected result format.

import { fal } from "@fal-ai/client";

const result = await fal.queue.result("fal-ai/ltx-video", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);

4. Files#

Some attributes in the API accept file URLs as input. Whenever that's the case you can pass your own URL or a Base64 data URI.

Data URI (base64)#

You can pass a Base64 data URI as a file input. The API will handle the file decoding for you. Keep in mind that for large files, this alternative although convenient can impact the request performance.

Hosted files (URL)#

You can also pass your own URLs as long as they are publicly accessible. Be aware that some hosts might block cross-site requests, rate-limit, or consider the request as a bot.

Uploading files#

We provide a convenient file storage that allows you to upload files and use them in your requests. You can upload files using the client API and use the returned URL in your requests.

import { fal } from "@fal-ai/client";

const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await fal.storage.upload(file);

Read more about file handling in our file upload guide.

5. Schema#

Input#

prompt string* required

The prompt to generate the video from.

negative_prompt string

The negative prompt to generate the video from. Default value: "low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly"

seed integer

The seed to use for random number generation.

num_inference_steps integer

The number of inference steps to take. Default value: 30

guidance_scale float

The guidance scale to use. Default value: 3

{
  "prompt": "A man stands waist-deep in a crystal-clear mountain pool, his back turned to a massive, thundering waterfall that cascades down jagged cliffs behind him. He wears a dark blue swimming shorts and his muscular back glistens with water droplets. The camera moves in a dynamic circular motion around him, starting from his right side and sweeping left, maintaining a slightly low angle that emphasizes the towering height of the waterfall. As the camera moves, the man slowly turns his head to follow its movement, his expression one of awe as he gazes up at the natural wonder. The waterfall creates a misty atmosphere, with sunlight filtering through the spray to create rainbow refractions. The water churns and ripples around him, reflecting the dramatic landscape. The handheld camera movement adds a subtle shake that enhances the raw, untamed energy of the scene. The lighting is natural and bright, with the sun positioned behind the waterfall, creating a backlit effect that silhouettes the falling water and illuminates the mist.",
  "negative_prompt": "low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly",
  "num_inference_steps": 30,
  "guidance_scale": 3
}

Output#

video File* required

The generated video.

seed integer* required

The seed used for random number generation.

{
  "video": {
    "url": "",
    "content_type": "image/png",
    "file_name": "z9RV14K95DvU.png",
    "file_size": 4404019
  }
}

Other types#

File#

url string* required

The URL where the file can be downloaded from.

content_type string

The mime type of the file.

file_name string

The name of the file. It will be auto-generated if not provided.

file_size integer

The size of the file in bytes.

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