POST gen2/extend

Extend the video by 4 seconds

August 8, 2024 (April 28, 2025)

Runway website no longer supports Gen-2. Consider migrating to Gen-3 or Gen-4.

Request Headers
Request Body
Responses
Model
Examples
Try It

Runway AI Tools » Audio tools » Text/Image to Video » Gen-2 » Extend Video.

https://api.useapi.net/v1/runwayml/gen2/extend

Request Headers

Authorization: Bearer {API token}
Content-Type: application/json
# Alternatively you can use multipart/form-data
# Content-Type: multipart/form-data

API token is required, see Setup useapi.net for details.

Request Body

{
    "assetId": "Required assetId of video asset you want to extend",
    "interpolate": true,
    "motion": 10,
    "horizontal": -10,
    "vertical": -5,
    "roll": -1,
    "zoom": 2,
    "pan": 5,
    "tilt": 10,
    "seed": 12345678,
    "exploreMode": true,
    "replyUrl": "Place your call back URL here",
    "replyRef": "Place your reference id here",
    "maxJobs": 5,
}

assetId is required. Specify the video assetId you want extend. Use GET /assets/?mediaType=video to see the list of video assets. To upload a new video asset use POST /assets.
interpolate is optional.
Supported values: true (default), false.
motion is optional. Increase or decrease the intensity of motion in your video. Higher values result in more motion. This parameter is not compatible with other motion parameters below.
Supported values: 1…10.
horizontal is optional. Specify horizontal motion.
Supported values: -10…10.
vertical is optional. Specify vertical motion.
Supported values: -10…10.
roll is optional. Specify roll motion.
Supported values: -10…10.
zoom is optional. Specify zoom motion.
Supported values: -10…10.
pan is optional. Specify pan motion.
Supported values: -10…10.
tilt is optional. Specify tilt motion.
Supported values: -10…10.
seed is optional.
Valid range 1…4294967294.
exploreMode is optional. Set to true if you have a Runway Unlimited plan and wish to execute relaxed generation. You are not charged credits for Explore mode generations.
replyUrl is optional, if not provided value from useapi.net account will be used.
Place here your callback URL. API will call the provided replyUrl once Runway task completed or failed.
Maximum length 1024 characters.
We recommend using sites like webhook.site to test callback URL functionality.
replyRef is optional, place here your reference id which will be stored and returned along with this Runway task response / result.
Maximum length 1024 characters.
maxJobs is optional, if not provided value for referenced by video assetId account will be used.
Valid range: 1…10.

Responses

200 OK

Use returned taskId to retrieve task status and results using GET /tasks/taskId. The generated video url can be found in the artifacts array of the task with the status SUCCEEDED.

If you specify the optional parameter replyUrl the API will call the provided replyUrl with task progress updates until the task is complete or fails.

{
  "taskId": "user:user_id-runwayml:account_email-task:task_uuid",
  "id": "<uuid>",
  "name": "<name>",
  "image": null,
  "createdAt": "2024-08-01T01:02:03.456Z",
  "updatedAt": "2024-08-01T01:02:03.456Z",
  "taskType": "gen2",
  "options": {
    "name": "<name>",
    "seconds": 4,
    "gen2Options": {
      "mode": "gen2",
      "seed": 12345678,
      "interpolate": true,
      "upscale": true,
      "watermark": false,
      "motion_score": 22,
      "use_motion_score": true,
      "use_motion_vectors": false,
      "init_video": "<original video url>",
      "extended_from_task_id": "<user:user_id-runwayml:account_email-task:parent_task_uuid>"
    },
    "exploreMode": false,
    "assetGroupName": "Generative Video",
    "recordingEnabled": true
  },
  "status": "PENDING",
  "error": null,
  "progressText": null,
  "progressRatio": null,
  "estimatedTimeToStartSeconds": 0,
  "artifacts": [],
  "sharedAsset": null,
  "replyUrl": "https://webhook.site/abc",
  "replyRef": "<your optional reference id>",
  "code": 200
}

400 Bad Request

{
  "error": "<Error message>",
  "code": 400
}

401 Unauthorized

{
  "error": "Unauthorized",
  "code": 401
}

404 Not Found

{
    "error": "Unable to retrieve assetId <uuid> (Not found.)",
    "code": 404
}

412 Insufficient credits

You do not have enough credits to run this task.

{
    "error": "You do not have enough credits to run this task."
}

429 Too Many Requests

Wait in a loop for at least 10..30 seconds and retry again.

There are two possible cases for API response 429:

API query is full and can not accept new gen2/extend requests. Size of query defined by maxJobs optional parameter.

{
    "error": "Account <Runway account email> is busy executing <Account maxJobs> tasks",
    "runningTasks": {
        "<Runway account email>": [
            {
                "email": "<Runway account email>",
                "taskId": "user:user_id-runwayml:account_email-task:task_#1_uuid",
                "id": "<uuid>",
                "replyUrl": "<replyUrl if provided>",
                "replyRef": "<replyRef if provided>"
            },
            {
                "email": "<Runway account email>",
                "taskId": "user:user_id-runwayml:account_email-task:task_#N_uuid",
                "id": "<uuid>",
                "replyUrl": "<replyUrl if provided>",
                "replyRef": "<replyRef if provided>"
            }
        ]
    },
    "code": 429
}

The API received an HTTP response status 429 from Runway. Runway has dynamic query management and may limit the number of simultaneously executed tasks based on internal service load and policies.

{
    "error": "You have too many tasks running or pending. Please wait for some of them to finish before starting more."
}

Model

{ // TypeScript, all fields are optional
  taskId: string,
  id: string,
  name: string,
  image: any,
  createdAt: string,
  updatedAt: string,
  taskType: string,
  options: {
    name: string,
    seconds: number,
    gen2Options: {
      mode: string,
      seed: number,
      interpolate: boolean,
      upscale: boolean,
      watermark: boolean,
      motion_score: number,
      use_motion_score: boolean,
      use_motion_vectors: boolean,
      motion_vector: {
        x: number,
        y: number,
        r: number,
        z: number,
        bg_x_pan: number,
        bg_y_pan: number
      },
      init_video: string,
      extended_from_task_id: string
    },
    exploreMode: boolean,
    assetGroupName: string,
    recordingEnabled: boolean
  },
  status: string,
  progressText: any,
  progressRatio: any,
  estimatedTimeToStartSeconds: number,
  artifacts: any[],
  sharedAsset: any,
  error: {
    errorMessage: string,
    reason: string,
    message: string,
    moderation_category: string,
    tally_asimov: boolean
  },
  code: number,
  replyUrl: string,
  replyRef: string
}

Examples

curl -H "Accept: application/json" \
     -H "Content-Type: application/json" \
     -H "Authorization: Bearer …" \
     -X POST "https://api.useapi.net/v1/runwayml/gen2/extend" \
     -d '{"assetId": "…" }'

const assetId = "assetId of video asset";      
const apiUrl = `https://api.useapi.net/v1/runwayml/gen2/extend`; 
const token = "API token";
const data = { 
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${token}`,
    'Content-Type': 'application/json' }
};
data.body = JSON.stringify({ 
  assetId
});
const response = await fetch(apiUrl, data);
const result = await response.json();
console.log("response", {response, result});

import requests
assetId = "assetId of video asset"      
apiUrl = f"https://api.useapi.net/v1/runwayml/gen2/extend" 
token = "API token"
headers = {
    "Content-Type": "application/json", 
    "Authorization" : f"Bearer {token}"
}
body = {
    "assetId": f"{assetId}"
}
response = requests.post(apiUrl, headers=headers, json=body)
print(response, response.json())