Veo 3.1 Video Extend: Continuity-Preserving Video-to-Video Generation on playground and API | RunComfy
Veo 3.1 Extend Video extends short Veo clips into longer, seamless videos with scene-aware transitions, consistent style, and 1080p quality for filmmakers, marketers, and creative production workflows.
Table of contents
1. Get started
Use RunComfy's API to run google-deepmind/veo-3-1/extend-video. For accepted inputs and outputs, see the model's schema.
curl --request POST \
--url https://model-api.runcomfy.net/v1/models/google-deepmind/veo-3-1/extend-video \
--header "Content-Type: application/json" \
--header "Authorization: Bearer <token>" \
--data '{
"prompt": "The warrior raises his weapon high, and with a thunderous roar, the troops surge forward. Spears lower in unison as the formation begins to move, footsteps pounding the ground. The camera pulls back into a wide shot, revealing waves of warriors charging across the battlefield. Dust clouds thicken, sunlight cuts through the haze, and the distant enemy lines come into view, heightening the tension just before the clash.",
"video_url": "https://playgrounds-storage-public.runcomfy.net/tools/7282/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/google-deepmind/veo-3-1/extend-video \
--header "Content-Type: application/json" \
--header "Authorization: Bearer <token>" \
--data '{
"prompt": "The warrior raises his weapon high, and with a thunderous roar, the troops surge forward. Spears lower in unison as the formation begins to move, footsteps pounding the ground. The camera pulls back into a wide shot, revealing waves of warriors charging across the battlefield. Dust clouds thicken, sunlight cuts through the haze, and the distant enemy lines come into view, heightening the tension just before the clash.",
"video_url": "https://playgrounds-storage-public.runcomfy.net/tools/7282/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": {
"prompt": {
"title": "Prompt",
"description": "",
"type": "string",
"default": "The warrior raises his weapon high, and with a thunderous roar, the troops surge forward. Spears lower in unison as the formation begins to move, footsteps pounding the ground. The camera pulls back into a wide shot, revealing waves of warriors charging across the battlefield. Dust clouds thicken, sunlight cuts through the haze, and the distant enemy lines come into view, heightening the tension just before the clash."
},
"aspect_ratio": {
"title": "Aspect Ratio (W:H)",
"description": "The aspect ratio of the generated video.",
"type": "string",
"enum": [
"auto",
"16:9",
"9:16"
],
"default": "auto"
},
"duration": {
"title": "Duration",
"description": "The duration of the generated video.",
"type": "string",
"enum": [
"7s"
],
"default": "7s"
},
"resolution": {
"title": "Resolution",
"description": "The resolution of the generated video.",
"type": "string",
"enum": [
"720p"
],
"default": "720p"
},
"generate_audio": {
"title": "Generate Audio",
"description": "Whether to generate audio for the video.",
"type": "boolean",
"default": true
},
"video_url": {
"title": "Video URL",
"description": "URL of the video to extend. The video should be 720p or 1080p resolution in 16:9 or 9:16 aspect ratio.",
"type": "string",
"default": "https://playgrounds-storage-public.runcomfy.net/tools/7282/media-files/input-1-1.mp4"
}
}
}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" }
}
}
}
}RunComfy is the premier ComfyUI platform, offering ComfyUI online environment and services, along with ComfyUI workflows featuring stunning visuals. RunComfy also provides AI Models, enabling artists to harness the latest AI tools to create incredible art.