POST gen4_5/create

Create a video using text prompt

December 15, 2025

Request Headers
Request Body
Responses
Model
Examples
Try It

Gen-4.5 currently is a text-to-video only model that generates 720p 16:9 videos from text prompts.

Please be aware that Runway’s moderation system analyzes your text prompts and may fail task with moderation message if the prompt is determined to be offensive. Runway monitors the rate and the number of moderated tasks, which may result in your account being suspended when the internal threshold is exceeded.

https://api.useapi.net/v1/runwayml/gen4_5/create

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

{
    "email": "Optional Runway account email",
    "text_prompt": "Required text prompt",
    "seconds": 5,
    "seed": 12345678,
    "exploreMode": true,
    "replyUrl": "Place your call back URL here",
    "replyRef": "Place your reference id here",
    "maxJobs": 5
}

email is optional. If not specified, the API will randomly select an available account with capacity for load balancing. Use GET /accounts to see the list of linked Runway accounts.
text_prompt is required. Describe your video scene. Maximum length: 5000 characters.
seconds is optional. Specify desired length of the video in seconds. Supported values: 5 (default), 8, 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 specified account will be used. Valid range: 1…10. Runway has dynamic query capacity and guarantees that, for a given account, at least one job will run — often two, and very rarely, three. If you have a single account linked, keep adding new jobs until you receive a 429 response. Once you get a 429, wait for xx seconds or until at least one job completes, then try again. If you need to run more jobs in parallel, simply add more Runway accounts.

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.

{
  "task": {
    "taskId": "user:user_id-runwayml:account_email-task:task_uuid",
    "id": "<uuid>",
    "name": "<name>",
    "image": null,
    "createdAt": "2024-12-13T01:02:03.456Z",
    "updatedAt": "2024-12-13T01:02:03.456Z",
    "taskType": "gen4.5",
    "options": {
        "name": "<name>",
        "route": "t2v",
        "seconds": 5,
        "text_prompt": "<your text prompt>",
        "seed": 12345789,
        "exploreMode": true,
        "watermark": false,
        "width": 1280,
        "height": 720
    },
    "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
}

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 gen4_5/create 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
  task: {
    taskId: string,
    id: string,
    name: string,
    image: string,
    createdAt: string,
    updatedAt: string,
    taskType: string,
    options: {
          name: string,
          seconds: number,
          text_prompt: string,
          seed: number,
          exploreMode: boolean,
          watermark: boolean,
          route: string,
          width: number,
          height: number,
          assetGroupId: string
    },
    status: string,
    progressText: string,
    progressRatio: number,
    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/gen4_5/create" \
     -d '{"email": "[email protected]", "text_prompt": "A cinematic shot of a sunset over the ocean"}'

const email = "[email protected]";
const text_prompt = "A cinematic shot of a sunset over the ocean";
const apiUrl = `https://api.useapi.net/v1/runwayml/gen4_5/create`;
const token = "API token";
const data = {
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${token}`,
    'Content-Type': 'application/json' }
};
data.body = JSON.stringify({
  email, text_prompt
});
const response = await fetch(apiUrl, data);
const result = await response.json();
console.log("response", {response, result});

import requests
email = "[email protected]"
text_prompt = "A cinematic shot of a sunset over the ocean"
apiUrl = f"https://api.useapi.net/v1/runwayml/gen4_5/create"
token = "API token"
headers = {
    "Content-Type": "application/json",
    "Authorization" : f"Bearer {token}"
}
body = {
    "email": f"{email}",
    "text_prompt": f"{text_prompt}"
}
response = requests.post(apiUrl, headers=headers, json=body)
print(response, response.json())