Inference
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("fal-ai/wan-i2v-lora", {
input: {
prompt: "Cars race in slow motion.",
image_url: "https://storage.googleapis.com/falserverless/gallery/car_720p.png"
},
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("fal-ai/wan-i2v-lora", {
input: {
prompt: "Cars race in slow motion.",
image_url: "https://storage.googleapis.com/falserverless/gallery/car_720p.png"
},
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("fal-ai/wan-i2v-lora", {
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("fal-ai/wan-i2v-lora", {
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.
prompt string* requiredThe text prompt to guide video generation.
negative_prompt stringNegative prompt for video generation. Default value: "bright colors, overexposed, static, blurred details, subtitles, style, artwork, painting, picture, still, overall gray, worst quality, low quality, JPEG compression residue, ugly, incomplete, extra fingers, poorly drawn hands, poorly drawn faces, deformed, disfigured, malformed limbs, fused fingers, still picture, cluttered background, three legs, many people in the background, walking backwards"
image_url string* requiredURL of the input image. If the input image does not match the chosen aspect ratio, it is resized and center cropped.
num_frames integerNumber of frames to generate. Must be between 81 to 100 (inclusive). If the number of frames is greater than 81, the video will be generated with 1.25x more billing units. Default value: 81
frames_per_second integerFrames per second of the generated video. Must be between 5 to 24. Default value: 16
seed integerRandom seed for reproducibility. If None, a random seed is chosen.
resolution ResolutionEnumResolution of the generated video (480p or 720p). 480p is 0.5 billing units, and 720p is 1 billing unit. Default value: "720p"
Possible enum values: 480p, 720p
num_inference_steps integerNumber of inference steps for sampling. Higher values give better quality but take longer. Default value: 30
guide_scale floatClassifier-free guidance scale. Higher values give better adherence to the prompt but may decrease quality. Default value: 5
shift floatShift parameter for video generation. Default value: 5
enable_safety_checker booleanIf set to true, the safety checker will be enabled. Disabling it requires account authorization; unauthorized requests are always checked.
enable_prompt_expansion booleanWhether to enable prompt expansion.
aspect_ratio AspectRatioEnumAspect ratio of the output video. Default value: "16:9"
Possible enum values: auto, 16:9, 9:16, 1:1
LoRA weights to be used in the inference.
reverse_video booleanIf true, the video will be reversed.
turbo_mode booleanIf true, the video will be generated faster with no noticeable degradation in the visual quality. Default value: true
{
"prompt": "Cars race in slow motion.",
"negative_prompt": "bright colors, overexposed, static, blurred details, subtitles, style, artwork, painting, picture, still, overall gray, worst quality, low quality, JPEG compression residue, ugly, incomplete, extra fingers, poorly drawn hands, poorly drawn faces, deformed, disfigured, malformed limbs, fused fingers, still picture, cluttered background, three legs, many people in the background, walking backwards",
"image_url": "https://storage.googleapis.com/falserverless/gallery/car_720p.png",
"num_frames": 81,
"frames_per_second": 16,
"resolution": "720p",
"num_inference_steps": 30,
"guide_scale": 5,
"shift": 5,
"enable_safety_checker": true,
"enable_prompt_expansion": false,
"aspect_ratio": "16:9",
"loras": [],
"turbo_mode": true
}The generated video file.
seed integer* requiredThe seed used for generation.
{
"video": {
"url": "https://storage.googleapis.com/falserverless/gallery/wan-i2v-example.mp4"
}
}path string* requiredURL or the path to the LoRA weights.
weight_name stringName of the LoRA weight. Used only if path is a Hugging Face repository, and required only if you have more than 1 safetensors file in the repo.
scale floatThe scale of the LoRA weight. This is used to scale the LoRA weight
before merging it with the base model. Default value: 1
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.