Video Extend

# Video Extend

Continue an existing video clip past its per-call duration cap, or chain a narrative shot-by-shot from a single seed. This skill routes to Google Veo 3-1's `extend-video` endpoints and ships the documented prompting patterns + the exact `runcomfy run` invoke.

[runcomfy.com](https://www.runcomfy.com/?utm_source=skills.sh&utm_medium=skill&utm_campaign=video-extend) · [Veo 3-1 extend-video](https://www.runcomfy.com/models/google-deepmind/veo-3-1/extend-video?utm_source=skills.sh&utm_medium=skill&utm_campaign=video-extend) · [CLI docs](https://docs.runcomfy.com/cli/introduction?utm_source=skills.sh&utm_medium=skill&utm_campaign=video-extend)

## Powered by the RunComfy CLI

```bash # 1. Install (see runcomfy-cli skill for details) npm i -g @runcomfy/cli # or: npx -y @runcomfy/cli --version

# 2. Sign in runcomfy login # or in CI: export RUNCOMFY_TOKEN=<token>

# 3. Extend runcomfy run google-deepmind/veo-3-1/extend-video \ --input '{"video_url": "https://...", "prompt": "..."}' \ --output-dir ./out ```

CLI deep dive: [`runcomfy-cli`](https://www.skills.sh/agentspace-so/runcomfy-agent-skills/runcomfy-cli) skill.

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## Pick the right endpoint

Listed newest first. Both endpoints are Google Veo 3-1; pick by quality/latency trade-off.

**Veo 3-1 Extend** — `google-deepmind/veo-3-1/extend-video` *(default)* > Continues an existing Veo clip with consistent motion, lighting, identity, and physics. > Pick for: hero-quality extends, final-delivery cuts, chained narrative shots that need to look like one continuous take. > Avoid for: cost-sensitive iteration — drop to **Veo 3-1 Fast Extend**.

**Veo 3-1 Fast Extend** — [`google-deepmind/veo-3-1/fast/extend-video`](https://www.runcomfy.com/models/google-deepmind/veo-3-1/fast/extend-video?utm_source=skills.sh&utm_medium=skill&utm_campaign=video-extend) > Faster Veo 3-1 extend at lower per-call cost. > Pick for: iteration on extend compositions, multi-shot drafts. > Avoid for: final delivery — use full **Veo 3-1 Extend**.

The agent picks one and supplies the source video URL + a continuation prompt.

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## Route: Veo 3-1 Extend

**Model**: `google-deepmind/veo-3-1/extend-video` (or `/fast/extend-video`) **Catalog**: [Veo 3-1 extend](https://www.runcomfy.com/models/google-deepmind/veo-3-1/extend-video?utm_source=skills.sh&utm_medium=skill&utm_campaign=video-extend) · [Veo 3-1 fast extend](https://www.runcomfy.com/models/google-deepmind/veo-3-1/fast/extend-video?utm_source=skills.sh&utm_medium=skill&utm_campaign=video-extend) · [`veo-3` collection](https://www.runcomfy.com/models/collections/veo-3?utm_source=skills.sh&utm_medium=skill&utm_campaign=video-extend)

### Invoke

```bash runcomfy run google-deepmind/veo-3-1/extend-video \ --input '{ "video_url": "https://your-cdn.example/source-clip.mp4", "prompt": "The camera continues pushing in slowly. The character looks down at the object, then turns toward the window. Soft daylight, no other motion in the background." }' \ --output-dir ./out ```

### Prompting tips

- **The source video provides identity, lighting, framing, and physics.** Your prompt describes only what happens **next** — don't re-describe the scene. - **Anchor the camera explicitly**: "camera continues pushing in", "camera stays static", "slow dolly out". Without an anchor the camera tends to drift. - **One main beat per extend.** "Character turns and walks toward camera" is one beat. "Character turns, walks toward camera, then sits down" is three beats — split into separate extend calls. - **Chain consecutive extends** by feeding the output of one extend call as the input to the next. Identity drift accumulates per generation, so keep individual extends short (3–5 s) for long chains.

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## Common patterns

### Single clip → 16s feature - Start with an 8s Veo 3-1 i2v or t2v clip - Run `extend-video` once → 16s total. Same prompt rhythm for the second 8s.

### Story beats (shot by shot) - Beat 1: t2v generates establishing shot - Beat 2: feed output to `extend-video` with prompt "camera cuts to medium close-up; character speaks line" - Beat 3: extend again with "character reaches for object on table" - Each extend call is one beat. Identity holds across cuts for ~3–4 chained extends; beyond that prepare to re-anchor with an i2v.

### Cost-controlled iteration - Use **Fast Extend** for first 2-3 drafts. Lock the final beat sequence on full **Extend**.

### What this skill doesn't do (and what does) - **Image-to-video from scratch**: use [`image-to-video`](https://www.skills.sh/agentspace-so/runcomfy-agent-skills/image-to-video) or [`ai-video-generation`](https://www.skills.sh/agentspace-so/runcomfy-agent-skills/ai-video-generation). - **Stylized restyle of an existing video**: use [`video-edit`](https://www.skills.sh/agentspace-so/runcomfy-agent-skills/video-edit). - **Talking-head extend with audio sync**: use [`ai-avatar-video`](https://www.skills.sh/agentspace-so/runcomfy-agent-skills/ai-avata