ltx/ltx-2/retake-video
Modify video inputs into synchronized 4K motion with unified audio-video generation, fast modes, and open-source access for cinematic, high-fidelity creative production.
Table of contents
1. Get started
Use RunComfy's API to run ltx/ltx-2/retake-video. For accepted inputs and outputs, see the model's schema.
curl --request POST \
--url https://model-api.runcomfy.net/v1/models/ltx/ltx-2/retake-video \
--header "Content-Type: application/json" \
--header "Authorization: Bearer <token>" \
--data '{
"prompt": "Change the coat to red",
"video_url": "https://playgrounds-storage-public.runcomfy.net/tools/7236/media-files/input-1-1.mp4"
}'2. Authentication
Set the YOUR_API_TOKEN environment variable with your API key (manage keys in your Profile) and include it on every request as a Bearer token via the Authorization header: Authorization: Bearer $YOUR_API_TOKEN.
3. API reference
Submit a request
Submit an asynchronous generation job and immediately receive a request_id plus URLs to check status, fetch results, and cancel.
curl --request POST \
--url https://model-api.runcomfy.net/v1/models/ltx/ltx-2/retake-video \
--header "Content-Type: application/json" \
--header "Authorization: Bearer <token>" \
--data '{
"prompt": "Change the coat to red",
"video_url": "https://playgrounds-storage-public.runcomfy.net/tools/7236/media-files/input-1-1.mp4"
}'Monitor request status
Fetch the current state for a request_id ("in_queue", "in_progress", "completed", or "cancelled").
curl --request GET \
--url https://model-api.runcomfy.net/v1/requests/{request_id}/status \
--header "Authorization: Bearer <token>"Retrieve request results
Retrieve the final outputs and metadata for the given request_id; if the job is not complete, the response returns the current state so you can continue polling.
curl --request GET \
--url https://model-api.runcomfy.net/v1/requests/{request_id}/result \
--header "Authorization: Bearer <token>"Cancel a request
Cancel a queued job by request_id, in-progress jobs cannot be cancelled.
curl --request POST \
--url https://model-api.runcomfy.net/v1/requests/{request_id}/cancel \
--header "Authorization: Bearer <token>"4. File inputs
Hosted file (URL)
Provide a publicly reachable HTTPS URL. Ensure the host allows server‑side fetches (no login/cookies required) and isn't rate‑limited or blocking bots. Recommended limits: images ≤ 50 MB (~4K), videos ≤ 100 MB (~2–5 min @ 720p). Prefer stable or pre‑signed URLs for private assets.
5. Schema
Input schema
{
"type": "object",
"title": "Input",
"required": [
"prompt",
"video_url"
],
"properties": {
"video_url": {
"title": "Video URL",
"description": "The URL of the video to retake.",
"type": "string",
"default": "https://playgrounds-storage-public.runcomfy.net/tools/7236/media-files/input-1-1.mp4"
},
"prompt": {
"title": "Prompt",
"description": "",
"type": "string",
"default": "Change the coat to red"
},
"start_time": {
"title": "Start Time",
"description": "The start time of the video to retake in seconds.",
"type": "float",
"minimum": 0,
"maximum": 20,
"default": 0
},
"duration": {
"title": "Duration",
"description": "The duration of the video to retake in seconds.",
"type": "float",
"minimum": 0,
"maximum": 20,
"default": 5
},
"retake_mode": {
"title": "Retake Mode",
"description": "The retake mode to use for the retake.",
"type": "string",
"enum": [
"replace_audio",
"replace_video",
"replace_audio_and_video"
],
"default": "replace_audio_and_video"
}
}
}Output schema
{
"output": {
"type": "object",
"properties": {
"image": {
"type": "string",
"format": "uri",
"description": "single image URL"
},
"video": {
"type": "string",
"format": "uri",
"description": "single video URL"
},
"images": {
"type": "array",
"description": "multiple image URLs",
"items": { "type": "string", "format": "uri" }
},
"videos": {
"type": "array",
"description": "multiple video URLs",
"items": { "type": "string", "format": "uri" }
}
}
}
}