---
title: Runway Aleph API — Video-to-Video Editing (2026)
description: Edit videos with Runway Aleph (Gen-4 video-to-video) via REST API. Swap subjects, restyle scenes, change camera angles — no RunwayML subscription. Free credits.
url: https://modelslab.com/runway-aleph
canonical: https://modelslab.com/runway-aleph
type: website
component: Seo/ModelPage
generated_at: 2026-05-20T04:59:39.789958Z
---

Available now on ModelsLab · Video Generation

Runway Aleph — Video-to-Video Editing via API
Edit any video with a text prompt. Swap subjects, restyle scenes, change camera angles.
---

[Try Runway Aleph](/models/runway_ml/gen4_aleph) [API Documentation](https://docs.modelslab.com)

Gen-4 Aleph — RunwayML's Video Editing Head
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Video-to-Video

### Instruction-Based Video Editing

Describe the edit in plain English — swap a subject, restyle a scene, change camera angle — Aleph applies it while preserving the source video's motion and timing.

Gen-4 Architecture

### RunwayML's Newest Editing Head

Built on Runway's Gen-4 foundation and purpose-trained for editing workflows, Aleph handles subject swaps, object insertion, style transfer, and camera reframing in a single prompt.

Temporal Coherence

### Consistent Across Frames

Maintains identity, lighting, and spatial structure across every frame — no flicker, no morphing, no manual keyframing.

One API Key

### No RunwayML Subscription

Call Aleph through the same ModelsLab REST API you already use for Kling, Seedance, Wan, and other video models. One key, one bill.

Async Friendly

### Webhook Callbacks

Pass a webhook URL — ModelsLab POSTs the edited MP4 to your endpoint when processing completes. Essential for batch jobs and production pipelines.

SDKs Included

### Python & JavaScript

Official SDKs wrap every endpoint including Aleph. Or call the REST API directly — we publish an OpenAPI spec for auto-generated clients.

Examples

See what Runway Aleph can edit
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Copy any prompt below and try it yourself in the [playground](/models/runway_ml/gen4_aleph).

Ad Creative Variation

“change the product in frame from the original bottle to a red can of sparkling water, keep the same motion, lighting, and background”

Style Transfer

“apply a cinematic film noir look — high contrast black and white, soft vignette, dramatic shadows”

Scene Replacement

“replace the background with a neon-lit Tokyo street at night, preserve the subject and their motion exactly”

Camera Reframe

“reframe this clip as a low-angle tracking shot instead of the current eye-level composition”

For Developers

A few lines of code.
Upload a clip. Describe the edit. Receive the edited MP4.
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ModelsLab handles the infrastructure: fast inference, auto-scaling, and a developer-friendly API. No GPU management needed.

- **Serverless:** scales to zero, scales to millions
- **Pay per clip,** no minimums
- **Python and JavaScript SDKs,** plus REST API

[API Documentation ](https://docs.modelslab.com)

PythonJavaScriptcURL

Copy

```
<code>import requests

response = requests.post(
    "https://modelslab.com/api/v7/video-fusion/video-to-video",
    json={
  "key": "YOUR_API_KEY",
  "prompt": "change the car colour to cherry red, keep everything else identical",
  "model_id": "gen4_aleph",
  "init_video": "https://example.com/source.mp4",
  "num_frames": 120,
  "output_type": "mp4"
}
)
print(response.json())</code>
```

FAQ

Common questions about Runway Aleph — Video-to-Video Editing via API
---

[Read the docs ](https://docs.modelslab.com)

### What is Runway Aleph?

Runway Aleph is RunwayML's Gen-4 video-to-video editing model. It takes an existing video clip plus a natural-language instruction and returns the same clip with the edit applied — subject swaps, style transfer, camera changes, object replacements — while preserving the source video's motion and timing.

### How is Aleph different from Runway Gen-3?

Gen-3 is primarily text-to-video (generate a clip from a prompt). Aleph is video-to-video (edit an existing clip from a prompt). Aleph is purpose-built for editing tasks where preserving the original motion matters — ads, film pre-viz, product demos — whereas Gen-3 is for generation from scratch.

### Do I need a RunwayML subscription to use Aleph?

No. ModelsLab routes Runway Aleph through a single REST API — you only need a ModelsLab API key. No separate RunwayML account, no separate billing, no quota management.

### What can Runway Aleph actually edit?

Subject and object swaps, style transfer (e.g. "make it anime", "cinematic film noir"), scene changes, camera angle shifts, lighting adjustments, and object additions. Anything describable in a short natural-language instruction that preserves the source video's structural layout.

### How long of a clip can Runway Aleph edit?

Per API call, Aleph handles 5-10 seconds of video. For longer edits, break the source into segments, edit each one, and stitch them together. Most production pipelines chunk at scene boundaries for consistency.

### What does Runway Aleph cost on ModelsLab?

Pay-per-generation pricing with transparent per-clip rates published on the pricing page. No monthly commitments, no credit systems. Every ModelsLab account gets free credits to test Aleph before picking a plan.

### Which model ID should I use in the API?

Use model_id 'gen4_aleph' at the /api/v7/video-fusion/video-to-video endpoint. Full request/response schema, sample payloads, and SDK snippets live at docs.modelslab.com.

### Does Runway Aleph support webhooks?

Yes. Pass a webhook URL in your request body and ModelsLab POSTs the completed edited video URL to your endpoint when processing finishes. Essential for long-running edits and batch workloads.

### Can I use Aleph alongside other ModelsLab video models?

Yes. Most production pipelines combine models: generate a base clip with Gen-3, Kling, or Wan 2.7, then edit it with Aleph. One API key, one billing account, one SDK — route between providers based on use case.

### Is there a Python SDK for Runway Aleph?

Yes. The ModelsLab Python SDK wraps every video endpoint including Aleph. You can also call the REST endpoint directly with the `requests` library — we publish an OpenAPI spec so any autogenerated client works in any language.

Ready to create?
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Start generating with Runway Aleph — Video-to-Video Editing via API on ModelsLab.

[Try Runway Aleph](/models/runway_ml/gen4_aleph) [API Documentation](https://docs.modelslab.com)

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*This markdown version is optimized for AI agents and LLMs.*

**Links:**
- [Website](https://modelslab.com)
- [API Documentation](https://docs.modelslab.com)
- [Blog](https://modelslab.com/blog)

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*Generated by ModelsLab - 2026-05-20*