Runway Gen 4.5 API - AI Video Generation APIs

by Runway

Runway Gen 4.5 API, developers can access Runway's industry-leading video generation for creating cinematic content from text and images. The API powers professional video production workflows, offering the quality and features demanded by filmmakers, advertisers, and media companies.

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Runway Gen-4.5 Image to Video API Documentation

https://gateway.pixazo.ai/runway-gen-4-5/v1

Authentication

All requests require an API key passed via header.

Header	Type	Required	Description
Ocp-Apim-Subscription-Key	string	Yes	Your API subscription key

Video Generation Request - Runway gen-4.5

Request Code

POST https://gateway.pixazo.ai/runway-gen-4-5/v1/gen-4.5/generate
Content-Type: application/json
Cache-Control: no-cache
Ocp-Apim-Subscription-Key: YOUR_API_KEY

{
  "prompt": "A golden retriever puppy chasing butterflies through a sunlit lavender field, slow motion, cinematic depth of field, warm afternoon light casting long shadows"
}

import requests

url = "https://gateway.pixazo.ai/runway-gen-4-5/v1/gen-4.5/generate"
headers = {
    "Content-Type": "application/json",
    "Cache-Control": "no-cache",
    "Ocp-Apim-Subscription-Key": "YOUR_API_KEY"
}
data = {
    "prompt": "A golden retriever puppy chasing butterflies through a sunlit lavender field, slow motion, cinematic depth of field, warm afternoon light casting long shadows"
}

response = requests.post(url, json=data, headers=headers)
print(response.json())

const url = 'https://gateway.pixazo.ai/runway-gen-4-5/v1/gen-4.5/generate';

const data = {
  prompt: 'A golden retriever puppy chasing butterflies through a sunlit lavender field, slow motion, cinematic depth of field, warm afternoon light casting long shadows'
};

fetch(url, {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'Cache-Control': 'no-cache',
    'Ocp-Apim-Subscription-Key': 'YOUR_API_KEY'
  },
  body: JSON.stringify(data)
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));

curl -X POST "https://gateway.pixazo.ai/runway-gen-4-5/v1/gen-4.5/generate" \
  -H "Content-Type: application/json" \
  -H "Cache-Control: no-cache" \
  -H "Ocp-Apim-Subscription-Key: YOUR_API_KEY" \
  --data-raw '{
    "prompt": "A golden retriever puppy chasing butterflies through a sunlit lavender field, slow motion, cinematic depth of field, warm afternoon light casting long shadows"
  }'

Output

{
  "request_id": "runway-gen-4-5_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "status": "QUEUED",
  "polling_url": "https://gateway.pixazo.ai/v2/requests/status/runway-gen-4-5_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
}

Try Now

Webhook (Optional)

Add the X-Webhook-URL header to your generate request to receive a POST callback instead of polling.

X-Webhook-URL: https://your-server.com/webhook/callback

Request Parameters - Video Generation Request

Parameter	Required	Type	Description
prompt	Yes	string	Text prompt describing the video to generate
image	No	string (URI)	Image URL for the first frame (image-to-video mode). If omitted, generates from text only
duration	No	integer	Video duration in seconds. Allowed values: 5, 10
aspect_ratio	No	string	Video aspect ratio. Allowed values: "16:9", "9:16", "4:3", "3:4", "1:1", "21:9"
seed	No	integer	Random seed for reproducible generation

Example Request

{
  "prompt": "An astronaut gazes through the cupola window of a space station at the glowing curve of Earth below, soft ambient light from control panels illuminates the cabin, the camera slowly drifts forward revealing the full panoramic viewport weightless tools float gently in the background, calm and awe-inspiring cinematic atmosphere",
  "image": "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/iss043e284928~medium.jpg",
  "duration": 10,
  "aspect_ratio": "21:9",
  "seed": 42
}

Response

{
  "request_id": "runway-gen-4-5_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "status": "QUEUED",
  "polling_url": "https://gateway.pixazo.ai/v2/requests/status/runway-gen-4-5_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
}

Request Headers

Header	Value
Content-Type	application/json
Cache-Control	no-cache
Ocp-Apim-Subscription-Key	Your API subscription key

Check Prediction Status - Runway gen-4.5

Request Code

POST https://gateway.pixazo.ai/runway-gen-4-5/v1/gen-4.5/prediction
Content-Type: application/json
Cache-Control: no-cache
Ocp-Apim-Subscription-Key: YOUR_API_KEY

{
  "prediction_id": "phzd8zp6anrmt0cwfcntztr2xc"
}

import requests

url = "https://gateway.pixazo.ai/runway-gen-4-5/v1/gen-4.5/prediction"
headers = {
    "Content-Type": "application/json",
    "Cache-Control": "no-cache",
    "Ocp-Apim-Subscription-Key": "YOUR_API_KEY"
}
data = {
    "prediction_id": "phzd8zp6anrmt0cwfcntztr2xc"
}

response = requests.post(url, json=data, headers=headers)
print(response.json())

const url = 'https://gateway.pixazo.ai/runway-gen-4-5/v1/gen-4.5/prediction';

const data = {
  prediction_id: 'phzd8zp6anrmt0cwfcntztr2xc'
};

fetch(url, {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'Cache-Control': 'no-cache',
    'Ocp-Apim-Subscription-Key': 'YOUR_API_KEY'
  },
  body: JSON.stringify(data)
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));

curl -X POST "https://gateway.pixazo.ai/runway-gen-4-5/v1/gen-4.5/prediction" \
  -H "Content-Type: application/json" \
  -H "Cache-Control: no-cache" \
  -H "Ocp-Apim-Subscription-Key: YOUR_API_KEY" \
  --data-raw '{
    "prediction_id": "phzd8zp6anrmt0cwfcntztr2xc"
  }'

Output

{
  "success": true,
  "id": "phzd8zp6anrmt0cwfcntztr2xc",
  "status": "succeeded",
  "output": "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/gen-4.5/phzd8zp6anrmt0cwfcntztr2xc_output_0.mp4",
  "created_at": "2026-02-20T13:09:52.341Z"
}

Try Now

Request Parameters - Check Prediction Status

Parameter	Required	Type	Description
prediction_id	Yes	string	The prediction ID returned from the generate endpoint

Example Request

{
  "prediction_id": "phzd8zp6anrmt0cwfcntztr2xc"
}

Response

{
  "success": true,
  "id": "phzd8zp6anrmt0cwfcntztr2xc",
  "status": "succeeded",
  "input": {
    "aspect_ratio": "16:9",
    "duration": 5,
    "prompt": "A golden retriever puppy chasing butterflies through a sunlit lavender field..."
  },
  "output": "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/gen-4.5/phzd8zp6anrmt0cwfcntztr2xc_output_0.mp4",
  "created_at": "2026-02-20T13:09:52.341Z"
}

Request Headers

Header	Value
Content-Type	application/json
Cache-Control	no-cache
Ocp-Apim-Subscription-Key	Your API subscription key

Response Handling

Common status codes for Check Prediction Status.

Code	Meaning
200	Success
400	Bad Request
401	Unauthorized
403	Forbidden
404	Not Found
429	Too Many Requests
500	Internal Server Error

Response Handling

Common status codes.

Code	Meaning
202	Accepted — Request queued
400	Bad Request
401	Unauthorized
402	Insufficient Balance
403	Forbidden
429	Too Many Requests
500	Internal Server Error

Error Responses

Queue system errors and model validation errors.

Queue System Errors

// 402 — Insufficient balance
{
  "error": "Insufficient Balance",
  "message": "Your wallet does not have enough balance."
}

// 400 — Model not found
{
  "error": "Model not found",
  "message": "Model 'runway-gen-4-5' not found or is disabled"
}

Error via Status/Webhook

{
  "request_id": "runway-gen-4-5_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "status": "ERROR",
  "model_id": "runway-gen-4-5",
  "error": "Description of the error",
  "output": null
}

Retrieving Results

Poll the universal status endpoint to check progress and retrieve results.

Endpoint

GET https://gateway.pixazo.ai/v2/requests/status/{request_id}
Ocp-Apim-Subscription-Key: YOUR_API_KEY

cURL Example

curl -H "Ocp-Apim-Subscription-Key: YOUR_API_KEY" \
  "https://gateway.pixazo.ai/v2/requests/status/runway-gen-4-5_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"

Response (Completed)

{
  "request_id": "runway-gen-4-5_019dxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "status": "COMPLETED",
  "model_id": "runway-gen-4-5",
  "error": null,
  "output": {
    "media_url": [
      "https://pub-582b7213209642b9b995c96c95a30381.r2.dev/v1/runway-gen-4-5_019dxxxx-xxxx/output.ext"
    ],
    "media_type": "application/octet-stream"
  },
  "created_at": "2026-03-31T10:00:00.000Z",
  "updated_at": "2026-03-31T10:00:15.000Z",
  "completed_at": "2026-03-31T10:00:15.000Z"
}

Response Fields

Field	Type	Description
request_id	string	Unique request identifier
status	string	QUEUED, PROCESSING, COMPLETED, FAILED, or ERROR
model_id	string	Model that processed the request
error	string\|null	Error message if failed
output.media_url	array	URLs to generated media (R2 CDN)
output.media_type	string	MIME type of the output
created_at	string	When request was created
completed_at	string\|null	When request completed
polling_url	string	Status URL (initial response only)

Status Values

Status	Description
QUEUED	Request accepted, waiting to be processed
PROCESSING	Being processed by the model
COMPLETED	Done — output contains the result
FAILED	Failed — check error field
ERROR	System error — not charged

Status Flow

QUEUED → PROCESSING → COMPLETED
                    → FAILED
                    → ERROR

Typical Workflow

Send a generate request to the API endpoint
Save the request_id from the response
Poll every 5-10 seconds: GET /v2/requests/status/{request_id}
When status is "COMPLETED", download from output.media_url

Tip: Use X-Webhook-URL header to get a callback instead of polling.

Runway Gen-4.5 Image to Video API Pricing

Resolution	Price (USD)
Per second of output video	$0.12