Name: Aleph 2.0 API: Video Editing by Runway
Brand: magicapi
SKU: api-magicapi-video-editing-api-frame-to-video-runwayml-aleph-2
Availability: InStock
Author: API Market

Shashank Agarwal

# 🎬 In-Context Video Editing API (Runway Aleph 2.0)

## Overview
Aleph 2.0 is Runway's in-context video editor. You send an existing video and a text `prompt` describing the change, and the model returns an edited version of the video. Runway describes it as "edit one frame to update an entire video", with support for longer clips (up to 30 seconds), multi-shot edits and image-level precision through keyframe references.

For more precise control you can pass up to 5 keyframe images (for example, frames you have already edited) and say where each one belongs in the video: the first frame, the last frame, or a timestamp in seconds.

Only `prompt` and `video` are required. Each request returns the URL of one video.

## Features
- **Prompt-based editing:** describe the edit in `prompt`, for example a change of weather, lighting, colors or style.
- **Input video:** `video` is the video to edit. It must be between 2 and 30 seconds long and less than 16MB.
- **Keyframe references:** `keyframe_images` takes up to 5 image URLs. `keyframe_positions` gives one position per image: `first`, `last`, or a timestamp in seconds written as a string (for example `"1.67"`).
- **Reproducible results:** set `seed` to an integer to repeat a generation.

## Use Cases
- **Changing time of day or weather:** turn a rainy street into a sunny afternoon, or day into night, across the whole clip.
- **Restyling footage:** change colors, lighting or the overall look of an existing shot without reshooting.
- **Applying an edited frame to a clip:** edit one frame in an image editor, then pass it as a keyframe so the change carries through the video.
- **Product and ad variations:** produce several versions of the same clip with different settings or color schemes.

## Visual Examples
This is a real request sent through api.market and the file it returned.

Prompt: "Make it a bright sunny afternoon with dry streets"

Inputs used: `prompt` and `video` as shown. No keyframe images and no seed were sent.

**Input video (`video`):** [Watch the input video](https://blog.api.market/wp-content/uploads/2026/10/hailuo-2.3-fast-output-api-market.mp4)

**Output video:** [Watch the example video](https://blog.api.market/wp-content/uploads/2026/10/aleph-2-output-api-market.mp4)

The input video was 5.875 seconds long and the returned video was also 5.875 seconds long.

## Pricing
- **Pay As You Go (PAYG) pricing:** you only pay for what you use.
- **Price:** $0.42 per API unit.
- **1 API unit** = 1 second of output video, rounded up to the next whole second. There are no variants or tiers: every second costs the same.
- **Worked example:** a 10 second output video is 10 units = $4.20. The example above returned 5.875 seconds of video, which rounds up to 6 units = $2.52.
- **Failed or cancelled predictions** are not billed.
- **GET requests** to check prediction status (GET /api/v1/magicapi/video-editing-api-frame-to-video-runwayml-aleph-2/predictions/{id}) are free and don't count toward API unit usage.
- **No monthly subscription fee.**

## API Documentation

### Base URL
`https://prod.api.market/api/v1/magicapi/video-editing-api-frame-to-video-runwayml-aleph-2`

### Authentication
Send your api.market API key in the `x-api-market-key` header on every request:
```
x-api-market-key: YOUR_API_MARKET_KEY
```

### Asynchronous Processing
**IMPORTANT:** This API is asynchronous.
1. POST `/predictions` with the model `version` and your `input`.
2. The API returns **201 Created** with a prediction `id` and a `status` of `starting` or `processing`. 201 means the request was accepted; it is not an error.
3. Poll GET `/predictions/{id}` until `status` is `succeeded`, `failed` or `canceled`.
4. When `status` is `succeeded`, `output` holds the URL of the edited video.
5. When `status` is `failed`, the `error` field explains why.

The example request above took about 2 minutes to finish, so allow a generous timeout when polling.

### Endpoints

#### Create a Prediction
`POST /predictions`

```bash
curl -X POST "https://prod.api.market/api/v1/magicapi/video-editing-api-frame-to-video-runwayml-aleph-2/predictions" \
  -H "Content-Type: application/json" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY" \
  -d '{
    "version": "67a723556e73936d6b4a1de17f10e033c94ee4310f8f80225511869b386a82e1",
    "input": {
      "prompt": "Make it a bright sunny afternoon with dry streets",
      "video": "https://blog.api.market/wp-content/uploads/2026/10/hailuo-2.3-fast-output-api-market.mp4"
    }
  }'
```

Response (201 Created):
```json
{
  "id": "ufawqhfynnddngldkgtslldrkq",
  "version": "67a723556e73936d6b4a1de17f10e033c94ee4310f8f80225511869b386a82e1",
  "status": "starting",
  "created_at": "2026-10-13T11:09:32.188Z"
}
```

#### Check Prediction Status
`GET /predictions/{id}`

```bash
curl -X GET "https://prod.api.market/api/v1/magicapi/video-editing-api-frame-to-video-runwayml-aleph-2/predictions/ufawqhfynnddngldkgtslldrkq" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY"
```

Response (200 OK) once the prediction has finished:
```json
{
  "id": "ufawqhfynnddngldkgtslldrkq",
  "status": "succeeded",
  "input": {
    "prompt": "Make it a bright sunny afternoon with dry streets",
    "video": "https://blog.api.market/wp-content/uploads/2026/10/hailuo-2.3-fast-output-api-market.mp4"
  },
  "output": "https://blog.api.market/wp-content/uploads/2026/10/aleph-2-output-api-market.mp4",
  "error": null,
  "created_at": "2026-10-13T11:09:32.188Z",
  "started_at": "2026-10-13T11:09:33.188Z",
  "completed_at": "2026-10-13T11:11:27.088Z"
}
```

### Input Parameters
| Parameter | Type | Required | Default | Allowed values | Description |
|---|---|---|---|---|---|
| `prompt` | string | Yes | none |  | Text prompt describing the edit to be applied to the input video. |
| `video` | string (URL) | Yes | none |  | Input video to edit. Videos must be between 2 and 30 seconds and less than 16MB. |
| `keyframe_images` | array of strings (URLs) | No | `[]` | Up to 5 images | Up to 5 optional keyframe images used as more precise control over edits. The position of each keyframe is given by `keyframe_positions`. |
| `keyframe_positions` | array of strings | No | `[]` | `first`, `last`, or a timestamp in seconds such as `"1.67"` | Position of each keyframe in `keyframe_images`. One entry per image. |
| `seed` | integer | No | none |  | Random seed. Set for reproducible generation |

### Output
`output` is a single URL (string) pointing to the edited MP4 video.

## Status Codes
- **200 OK:** prediction status returned.
- **201 Created:** prediction accepted. Poll GET `/predictions/{id}` for the result.
- **400 Bad Request:** invalid or missing input fields.
- **401 Unauthorized:** missing or invalid API key.
- **404 Not Found:** unknown prediction ID.
- **429 Too Many Requests:** too many requests in a short time. Wait and retry.
- **500 Internal Server Error:** server-side error. Retry after a short wait.

## Rate Limits

All plans allow 10 requests per second. Requests above that return `429 Too Many Requests`; back off before retrying and honour any `Retry-After` header. Polling a prediction with GET is free but still counts toward the per-second limit, so poll every 1 to 5 seconds rather than in a tight loop.

## Error Handling
- **Request errors (4xx):** check the response body, fix the input fields and send the request again.
- **Failed predictions:** when GET returns `status: "failed"`, read the `error` field and check that the input video is between 2 and 30 seconds and less than 16MB. Failed predictions are not billed.
- **Rate limits (429) and server errors (5xx):** retry with exponential backoff.

## Implementation Guide

### JavaScript
```javascript
const apiKey = "YOUR_API_MARKET_KEY";
const baseUrl = "https://prod.api.market/api/v1/magicapi/video-editing-api-frame-to-video-runwayml-aleph-2";

async function createPrediction(input) {
  const response = await fetch(`${baseUrl}/predictions`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "x-api-market-key": apiKey
    },
    body: JSON.stringify({ version: "67a723556e73936d6b4a1de17f10e033c94ee4310f8f80225511869b386a82e1", input })
  });
  if (response.status !== 201 && response.status !== 200) {
    throw new Error(`API error: ${response.status} ${await response.text()}`);
  }
  return response.json();
}

async function waitForPrediction(id, timeoutMs = 1200000, intervalMs = 5000) {
  const start = Date.now();
  while (Date.now() - start < timeoutMs) {
    const response = await fetch(`${baseUrl}/predictions/${id}`, {
      headers: { "x-api-market-key": apiKey }
    });
    if (!response.ok) {
      throw new Error(`API error: ${response.status} ${await response.text()}`);
    }
    const prediction = await response.json();
    if (prediction.status === "succeeded") return prediction.output;
    if (prediction.status === "failed" || prediction.status === "canceled") {
      throw new Error(`Prediction ${prediction.status}: ${prediction.error || "unknown error"}`);
    }
    await new Promise((resolve) => setTimeout(resolve, intervalMs));
  }
  throw new Error("Timed out waiting for the prediction");
}

const prediction = await createPrediction({
  "prompt": "Make it a bright sunny afternoon with dry streets",
  "video": "https://blog.api.market/wp-content/uploads/2026/10/hailuo-2.3-fast-output-api-market.mp4"
});
const output = await waitForPrediction(prediction.id);
console.log(output);
```

### Python
```python
import time
import requests

API_KEY = "YOUR_API_MARKET_KEY"
BASE_URL = "https://prod.api.market/api/v1/magicapi/video-editing-api-frame-to-video-runwayml-aleph-2"

def create_prediction(input_data):
    response = requests.post(
        f"{BASE_URL}/predictions",
        headers={"Content-Type": "application/json", "x-api-market-key": API_KEY},
        json={"version": "67a723556e73936d6b4a1de17f10e033c94ee4310f8f80225511869b386a82e1", "input": input_data},
    )
    if response.status_code not in (200, 201):
        raise Exception(f"API error: {response.status_code} {response.text}")
    return response.json()

def wait_for_prediction(prediction_id, timeout=1200, interval=5):
    start = time.time()
    while time.time() - start < timeout:
        response = requests.get(
            f"{BASE_URL}/predictions/{prediction_id}",
            headers={"x-api-market-key": API_KEY},
        )
        if response.status_code != 200:
            raise Exception(f"API error: {response.status_code} {response.text}")
        prediction = response.json()
        if prediction["status"] == "succeeded":
            return prediction["output"]
        if prediction["status"] in ("failed", "canceled"):
            raise Exception(f"Prediction {prediction['status']}: {prediction.get('error') or 'unknown error'}")
        time.sleep(interval)
    raise Exception("Timed out waiting for the prediction")

prediction = create_prediction({
  "prompt": "Make it a bright sunny afternoon with dry streets",
  "video": "https://blog.api.market/wp-content/uploads/2026/10/hailuo-2.3-fast-output-api-market.mp4"
})
print(wait_for_prediction(prediction["id"]))
```

### cURL
```bash
# Step 1: create the prediction (returns 201 Created with an id)
curl -X POST "https://prod.api.market/api/v1/magicapi/video-editing-api-frame-to-video-runwayml-aleph-2/predictions" \
  -H "Content-Type: application/json" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY" \
  -d '{
    "version": "67a723556e73936d6b4a1de17f10e033c94ee4310f8f80225511869b386a82e1",
    "input": {
      "prompt": "Make it a bright sunny afternoon with dry streets",
      "video": "https://blog.api.market/wp-content/uploads/2026/10/hailuo-2.3-fast-output-api-market.mp4"
    }
  }'

# Step 2: poll with the returned id until status is succeeded, failed or canceled
curl -X GET "https://prod.api.market/api/v1/magicapi/video-editing-api-frame-to-video-runwayml-aleph-2/predictions/ufawqhfynnddngldkgtslldrkq" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY"
```

## FAQ
**Q: How long can my input video be?**  
A: Between 2 and 30 seconds, and less than 16MB.

**Q: How do I use keyframe images?**  
A: Put up to 5 image URLs in `keyframe_images` and one position per image in `keyframe_positions`, in the same order. Each position is `first`, `last`, or a timestamp in seconds as a string, for example `["first", "2.5"]`.

**Q: How much will an edit cost?**  
A: You pay $0.42 per second of output video, rounded up to the next whole second. In the example on this page the output was the same length as the input video (5.875 seconds), billed as 6 units = $2.52.

**Q: Can I get the same result twice?**  
A: Set `seed` to the same integer with the same inputs to make the generation reproducible.

**Q: Is POST returning 201 an error?**  
A: No. 201 Created means the prediction was accepted. Use the returned `id` to poll GET `/predictions/{id}` until `status` is `succeeded`, `failed` or `canceled`.

## Contact Us

If you have any questions or need assistance, you can reach out to us through the embedded chat on the bottom right corner of the page or send an email to hello@magicapi.com.


Edit an existing video with a text prompt using Runway Aleph 2.0. Clips of 2 to 30 seconds, up to 5 optional keyframe images. $0.42 per second of output video.