> ## Documentation Index
> Fetch the complete documentation index at: https://apixo.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# LTX 2 19B
> Lightricks video generation API for text-to-video, image-to-video, and LoRA workflows
## Overview
LTX 2 19B is a Lightricks video generation model for text-to-video and image-to-video workflows. It also supports LoRA-conditioned variants when you need custom styles, characters, or structural guidance.
Use this page when you are ready to call the API after trying the model in the APIXO playground.
| Capability | Value |
| ---------------- | ------------------------------------------------------------------------------ |
| Model ID | `ltx-2-19b` |
| Modes | `text-to-video`, `image-to-video`, `text-to-video-LoRA`, `image-to-video-LoRA` |
| Prompt length | 1-5000 characters |
| Reference images | Exactly 1 URL for `image-to-video` and `image-to-video-LoRA` |
| Aspect ratios | `16:9`, `9:16` for text-to-video modes |
| Resolution tiers | `480p`, `720p`, `1080p` |
| Duration | 5-20 seconds |
| LoRA controls | Up to 3 LoRA items, each with `path` and `scale` |
| Seed | `-1`, or `1` through `2147483647` |
## Endpoint and authentication
Base URL:
```text theme={null}
https://api.apixo.ai/api/v1
```
| Method | Endpoint | Purpose |
| ------ | --------------------------------------- | ------------------------------------- |
| `POST` | `/generateTask/ltx-2-19b` | Submit a generation task |
| `GET` | `/statusTask/ltx-2-19b?taskId={taskId}` | Poll task status and retrieve results |
All requests require your APIXO API key:
```http theme={null}
Authorization: Bearer YOUR_API_KEY
```
Submit requests also require:
```http theme={null}
Content-Type: application/json
```
## Copy-paste async quickstart
This minimal request submits a text-to-video task and returns a `taskId`.
```bash theme={null}
curl -X POST "https://api.apixo.ai/api/v1/generateTask/ltx-2-19b" \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"request_type": "async",
"input": {
"mode": "text-to-video",
"prompt": "a cinematic shot of a small robot walking through a rainy neon street",
"resolution": "720p",
"duration": 10,
"aspect_ratio": "16:9"
}
}'
```
Successful response:
```json theme={null}
{
"code": 200,
"message": "success",
"data": {
"taskId": "task_12345678"
}
}
```
Save the `taskId`; you need it to poll for the final result.
## Poll for result
```bash theme={null}
curl -X GET "https://api.apixo.ai/api/v1/statusTask/ltx-2-19b?taskId=task_12345678" \
-H "Authorization: Bearer YOUR_API_KEY"
```
Processing response:
```json theme={null}
{
"code": 200,
"message": "success",
"data": {
"taskId": "task_12345678",
"state": "processing",
"createTime": 1767965610929
}
}
```
Success response:
```json theme={null}
{
"code": 200,
"message": "success",
"data": {
"taskId": "task_12345678",
"state": "success",
"resultJson": "{\"resultUrls\":[\"https://file.apixo.ai/video.mp4\"]}",
"createTime": 1767965610929,
"completeTime": 1767965652317,
"costTime": 41388
}
}
```
Failed response:
```json theme={null}
{
"code": 200,
"message": "success",
"data": {
"taskId": "task_12345678",
"state": "failed",
"failCode": "SensitiveContent",
"failMsg": "Content violates provider policy, please adjust the prompt",
"createTime": 1767965610929,
"completeTime": 1767965620132
}
}
```
Parse `resultJson` after `state` becomes `success`:
```javascript theme={null}
const payload = JSON.parse(data.resultJson);
const videoUrls = payload.resultUrls;
```
## Request body
### Text-to-video
```json theme={null}
{
"request_type": "async",
"input": {
"mode": "text-to-video",
"prompt": "a futuristic city with flying cars at sunset",
"resolution": "1080p",
"duration": 10,
"aspect_ratio": "16:9",
"seed": 54248617
}
}
```
### Image-to-video
```json theme={null}
{
"request_type": "async",
"input": {
"mode": "image-to-video",
"prompt": "make the scene cinematic with a slow camera push and soft motion",
"image_urls": [
"https://example.com/source.jpg"
],
"resolution": "720p",
"duration": 8
}
}
```
### Image-to-video with LoRA
```json theme={null}
{
"request_type": "async",
"input": {
"mode": "image-to-video-LoRA",
"prompt": "animate this character in a stylized studio lighting setup",
"image_urls": [
"https://example.com/source.jpg"
],
"resolution": "720p",
"duration": 8,
"loras": [
{
"path": "https://huggingface.co/username/model.safetensors?download=true",
"scale": 1.2
}
]
}
}
```
## Parameters
Result delivery mode. Use `async` for polling with `statusTask`, or `callback` for webhook delivery.
Required when `request_type` is `callback`. Must be a public HTTPS endpoint that can receive the final task payload. See [Webhooks](/docs/api-reference/webhooks).
LTX 2 19B input parameters.
Generation mode. Supported values: `text-to-video`, `image-to-video`, `text-to-video-LoRA`, `image-to-video-LoRA`.
Text prompt describing the desired video. Must be non-empty and no longer than 5000 characters.
Output resolution tier. Supported values: `480p`, `720p`, `1080p`.
Video duration in seconds. Must be a JSON integer from `5` through `20`.
Required for `image-to-video` and `image-to-video-LoRA`. Provide exactly 1 public, directly accessible image URL.
Applies to text-to-video modes only. Supported values: `16:9`, `9:16`. If omitted for text-to-video, the backend sends `16:9`.
Optional seed. Use `-1` to let the provider choose a random seed, or send an integer from `1` through `2147483647`.
Optional LoRA array, intended for LoRA modes. Supports up to 3 items.
Publicly downloadable LoRA model URL. The value must be a non-empty string.
LoRA strength. Must be a number from `0.0` through `4.0`.
## Response format
### Submit task response
`POST /generateTask/ltx-2-19b` returns a task ID when the task is accepted:
API status code. `200` means the task was accepted.
Human-readable status message.
Unique task identifier used with the status endpoint.
### Status response fields
Unique task identifier.
Current task state: `pending`, `processing`, `success`, or `failed`.
JSON string containing the generated video URLs in `resultUrls`. Present when `state` is `success`.
Machine-readable failure code. Present when `state` is `failed`.
Human-readable failure message. Present when `state` is `failed`.
Task creation timestamp in Unix milliseconds.
Task completion timestamp in Unix milliseconds. Present after completion.
Processing duration in milliseconds when available. Present after completion.
## Webhook callback mode
Use callback mode when your backend should receive the final result automatically instead of polling.
```bash theme={null}
curl -X POST "https://api.apixo.ai/api/v1/generateTask/ltx-2-19b" \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"request_type": "callback",
"callback_url": "https://your-server.com/webhooks/apixo",
"input": {
"mode": "text-to-video",
"prompt": "a clean product reveal video with a slow camera push-in",
"resolution": "720p",
"duration": 10,
"aspect_ratio": "16:9"
}
}'
```
The callback `data` object uses the same terminal fields as the status response. See [Webhooks](/docs/api-reference/webhooks) for delivery requirements and retry behavior.
## Billing
LTX 2 19B is billed per second. The backend selects the unit price by `resolution` and base vs LoRA mode, then multiplies that unit price by the submitted `duration`.
| Resolution | Base modes price | LoRA modes price | Minimum 5s cost |
| ---------- | ----------------- | ----------------- | --------------------------- |
| `480p` | `$0.012 / second` | `$0.015 / second` | Base `$0.06`; LoRA `$0.075` |
| `720p` | `$0.016 / second` | `$0.02 / second` | Base `$0.08`; LoRA `$0.10` |
| `1080p` | `$0.024 / second` | `$0.03 / second` | Base `$0.12`; LoRA `$0.15` |
Formula:
```text theme={null}
total cost = duration * selected per-second unit price
```
For current route and market comparison pricing, see [Pricing](https://apixo.ai/pricing).
## Latency and polling
Actual latency may vary by prompt complexity, duration, resolution, LoRA loading, provider queue load, and storage transfer time.
| Workload | Typical generation time | Recommended first poll | Poll interval |
| ---------- | ----------------------- | ------------------------------------ | ------------- |
| `480p` | 40s-60s | 40s after task creation | 5s |
| `720p` | 60s-90s | 60s after task creation | 5s |
| `1080p` | 90s-120s | 90s after task creation | 5s |
| LoRA modes | Add about 10s-20s | Add about 10s to the base first poll | 5s |
For production video workloads, use callback mode to avoid frequent polling while generation is still running.
Result URLs are normally stored for 15 days. Download and store important outputs promptly.
For image-to-video modes, provide exactly one source image. Public image URLs should be directly accessible by APIXO; JPG, PNG, or WebP files are the safest choice.
For LoRA workflows, use public downloadable model URLs such as Hugging Face or Civitai download links. Each LoRA item must include both `path` and `scale`, even if you want a neutral scale like `1.0`.
Rate limits and concurrency can vary by account, API key, and route. If you receive `429`, slow down requests and retry with backoff. For account-level details, see [System APIs](/docs/api-reference/system).
## Errors and troubleshooting
### HTTP errors
| Code | Meaning | What to do |
| ----- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------ |
| `400` | Invalid request body, missing `input`, missing `mode`, missing `prompt`, invalid `resolution`, invalid `duration`, invalid `seed`, invalid `image_urls`, or invalid `loras` | Fix the request before retrying |
| `401` | Missing or invalid API key | Check the `Authorization` header |
| `402` | Insufficient balance or quota | Add balance or switch account/key |
| `403` | Key or route cannot access the model | Check permissions and route strategy |
| `404` | Task not found when polling | Check the `taskId` and model endpoint |
| `429` | Rate limit or concurrency limit reached | Retry with exponential backoff |
| `500` | Server error or unknown upstream failure | Retry with backoff |
| `502` | Upstream provider or network error | Retry with backoff |
| `503` | Service temporarily unavailable or async queue is full | Retry later |
| `504` | Upstream timeout | Retry or use callback mode for long-running jobs |
### Validation notes
| Parameter | Backend behavior |
| --------------------- | -------------------------------------------------------------------------------------------------------------------- |
| `input.mode` | Required for routing. Must be one of `text-to-video`, `image-to-video`, `text-to-video-LoRA`, `image-to-video-LoRA`. |
| `input.prompt` | Required string. Must not be empty and cannot exceed 5000 characters. |
| `input.resolution` | Required string. Must be `480p`, `720p`, or `1080p`. |
| `input.duration` | Required JSON integer. Must be from `5` through `20`; quoted strings are not valid. |
| `input.image_urls` | Required for image-to-video modes. Must be an array with exactly 1 string URL. |
| `input.aspect_ratio` | Optional for text-to-video modes. Must be `16:9` or `9:16`; defaults to `16:9` when omitted. |
| `input.seed` | Optional JSON integer. Must be `-1`, or from `1` through `2147483647`. |
| `input.loras` | Optional array. If present, it cannot contain more than 3 items. |
| `input.loras[].path` | Required for each LoRA item. Must be a non-empty string. |
| `input.loras[].scale` | Required for each LoRA item. Must be numeric and from `0.0` through `4.0`. |
### Task failure codes
| Fail code | Meaning | What to do |
| ---------------------------------------------------------- | ------------------------------------------------------------ | ---------------------------------------------------------- |
| `SensitiveContent` / `InputOutputSensitiveContentDetected` | Prompt, input image, or output failed provider safety checks | Change the prompt or input image |
| `PromptInvalid` | Prompt was rejected or malformed | Adjust the prompt and retry |
| `ImageFormatIncorrect` / `InvalidImageSize` | Input image failed upstream image validation | Use a public, direct JPG, PNG, or WebP URL |
| `ImageNotAccess` | APIXO could not fetch an input URL | Use a public HTTP or HTTPS URL that returns `200` or `206` |
| `RateLimited` | Provider-side rate limit | Retry with exponential backoff |
| `Timeout` | Provider-side timeout | Retry, simplify the request, or use callback mode |
| `Unknown error` | Provider returned an unmapped failure | Retry with backoff or contact support with the `taskId` |
See [Error Codes](/docs/api-reference/errors) for the full error reference.
## Related links
* [Generation API Overview](/docs/models)
* [Generate Task](/docs/api-reference/generate-task)
* [Status Task](/docs/api-reference/status-task)
* [Webhooks](/docs/api-reference/webhooks)
* [Error Codes](/docs/api-reference/errors)
* [Parameter Specification](/docs/api-reference/parameters)
* [Routing Strategies](/docs/concepts/routing-strategies)
* [Pricing](https://apixo.ai/pricing)