Generate subject consistent videos using Lynx from ByteDance!
bytedance/lynx
Generate subject consistent videos using Lynx from ByteDance!
Inference
Commercial use
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The client provides a convenient way to interact with the model API.
npm install --save @fal-ai/clientThe @fal-ai/serverless-client package has been deprecated in favor of @fal-ai/client. Install the new package and update your imports — see client setup.
Set FAL_KEY as an environment variable in your runtime.
export FAL_KEY="YOUR_API_KEY"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("bytedance/lynx", {
input: {
image_url: "https://storage.googleapis.com/falserverless/example_inputs/lynx/example_in.png",
prompt: "A person carves a pumpkin on a porch in the evening. The camera captures their upper body as they draw a face with a marker, carefully cut along the lines, then lift the lid with both hands. Their face lights up with excitement as they peek inside"
},
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);The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.
import { fal } from "@fal-ai/client";
fal.config({
credentials: "YOUR_FAL_KEY"
});When running code on the client-side (e.g. in a browser, mobile app or GUI applications), make sure to not expose your FAL_KEY. Instead, use a server-side proxy to make requests to the API. For more information, check out our server-side integration guide.
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("bytedance/lynx", {
input: {
image_url: "https://storage.googleapis.com/falserverless/example_inputs/lynx/example_in.png",
prompt: "A person carves a pumpkin on a porch in the evening. The camera captures their upper body as they draw a face with a marker, carefully cut along the lines, then lift the lid with both hands. Their face lights up with excitement as they peek inside"
},
webhookUrl: "https://optional.webhook.url/for/results",
});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("bytedance/lynx", {
requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
logs: true,
});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("bytedance/lynx", {
requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);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.
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.
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.
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);The client will auto-upload the file for you if you pass a binary object (e.g. File, Data).
Read more about file handling in our file upload guide.
image_url string* requiredThe URL of the subject image to be used for video generation
prompt string* requiredText prompt to guide video generation
negative_prompt stringNegative prompt to guide what should not appear in the generated video Default value: "Bright tones, overexposed, blurred background, static, subtitles, style, works, paintings, images, overall gray, worst quality, low quality, JPEG compression residue, ugly, incomplete, extra fingers, poorly drawn hands, poorly drawn faces, deformed, disfigured, misshapen limbs, fused fingers, still picture, messy background, three legs, many people in the background, walking backwards"
num_inference_steps integerNumber of inference steps for sampling. Higher values give better quality but take longer. Default value: 50
seed integerRandom seed for reproducibility. If None, a random seed is chosen.
resolution ResolutionEnumResolution of the generated video (480p, 580p, or 720p) Default value: "720p"
Possible enum values: 480p, 580p, 720p
aspect_ratio AspectRatioEnumAspect ratio of the generated video (16:9, 9:16, or 1:1) Default value: "16:9"
Possible enum values: 16:9, 9:16, 1:1
ip_scale floatIdentity preservation scale. Controls how closely the generated video preserves the subject's identity from the reference image. Default value: 1
strength floatReference image scale. Controls the influence of the reference image on the generated video. Default value: 1
frames_per_second integerFrames per second of the generated video. Must be between 5 to 30. Default value: 16
guidance_scale floatClassifier-free guidance scale. Higher values give better adherence to the prompt but may decrease quality. Default value: 5
guidance_scale_2 floatImage guidance scale. Controls how closely the generated video follows the reference image. Higher values increase adherence to the reference image but may decrease quality. Default value: 2
num_frames integerNumber of frames in the generated video. Must be between 9 to 100. Default value: 81
enable_safety_checker booleanAuthorized callers may set false to request relaxed screening. Default value: true
{
"image_url": "https://storage.googleapis.com/falserverless/example_inputs/lynx/example_in.png",
"prompt": "A person carves a pumpkin on a porch in the evening. The camera captures their upper body as they draw a face with a marker, carefully cut along the lines, then lift the lid with both hands. Their face lights up with excitement as they peek inside",
"negative_prompt": "Bright tones, overexposed, blurred background, static, subtitles, style, works, paintings, images, overall gray, worst quality, low quality, JPEG compression residue, ugly, incomplete, extra fingers, poorly drawn hands, poorly drawn faces, deformed, disfigured, misshapen limbs, fused fingers, still picture, messy background, three legs, many people in the background, walking backwards",
"num_inference_steps": 50,
"resolution": "720p",
"aspect_ratio": "16:9",
"ip_scale": 1,
"strength": 1,
"frames_per_second": 16,
"guidance_scale": 5,
"guidance_scale_2": 2,
"num_frames": 81,
"enable_safety_checker": true
}The generated video file
seed integer* requiredThe seed used for generation
{
"video": {
"content_type": "video/mp4",
"url": "https://storage.googleapis.com/falserverless/example_outputs/lynx/example_out.mp4"
}
}url string* requiredThe URL where the file can be downloaded from.
content_type stringThe mime type of the file.
file_name stringThe name of the file. It will be auto-generated if not provided.
file_size integerThe size of the file in bytes.
width integerThe width of the video
height integerThe height of the video
fps floatThe FPS of the video
duration floatThe duration of the video
num_frames integerThe number of frames in the video