RunwayRunway Gen4 Ref API

Name: Runway Gen4 Ref API
Author: Runway

Generate a still image from up to 3 reference images with consistent identity.

Prompt

Reference Images

0/3 images

Aspect ratio

Billed at this model’s published rate.

Result

Your generations will appear here

Other models from Runway

Same vendor, same API call — the differences are below.

Model	Use case	Price	Resolution	Duration	Added
Runway Aleph 2	Video → Video	from $0.308 / sec	—	—	Jun 2026
Runway Avatar	Text → Video	No rate	—	—	Apr 2026
Runway Gen 4.5	Text → Video	from $0.132 / sec	—	5–10s	Feb 2026

Install the SDK

TypeScript targets Node 20+ and ships with types; Python needs 3.10+ and is async. Over REST there is nothing to install: call https://api.picsart.com from any HTTP client.

bash

npm install @picsart/ai-sdk

Authenticate

Send your Picsart API key as a bearer token. The SDK does it for you once the client is created.

import { createClient } from '@picsart/ai-sdk';

const ai = createClient({
  apiKey: process.env.PICSART_API_KEY, // sent as: Authorization: Bearer <key>
  apiUrl: 'https://api.picsart.com',
});

python

import os

from picsart_ai_sdk import create_client

ai = create_client(
    api_key=os.environ["PICSART_API_KEY"],  # sent as: Authorization: Bearer <key>
    api_url="https://api.picsart.com",
)

Make a request

Call the model by its id. Over REST, one endpoint serves every model: POST /workflows/v1/models/execute with the model id and its input in the body. The outer params is the envelope every workflow takes; the inner one is this model's input, with the same names generate() takes.

import { createClient } from '@picsart/ai-sdk';

const ai = createClient({
  apiKey: process.env.PICSART_API_KEY,
  apiUrl: 'https://api.picsart.com',
});

const result = await ai.generate('runway-gen4-ref', {
  prompt: "A serene mountain lake at golden hour, ultra detailed",
  aspectRatio: "16:9",
  imageUrls: [
    "https://cdn.example.com/input.jpg"
  ]
});

console.log(result.url); // image URL

python

import asyncio
import os

from picsart_ai_sdk import create_client


async def main() -> None:
    async with create_client(
        api_key=os.environ["PICSART_API_KEY"],
        api_url="https://api.picsart.com",
    ) as ai:
        result = await ai.generate("runway-gen4-ref", {
            "prompt": "A serene mountain lake at golden hour, ultra detailed",
            "aspectRatio": "16:9",
            "imageUrls": [
                "https://cdn.example.com/input.jpg",
            ],
        })

        print(result.url)  # image URL


asyncio.run(main())

bash

curl -X POST 'https://api.picsart.com/workflows/v1/models/execute' \
  -H 'Authorization: Bearer $PICSART_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
  "params": {
    "model": "runway-gen4-ref",
    "params": {
      "prompt": "A serene mountain lake at golden hour, ultra detailed",
      "aspectRatio": "16:9",
      "imageUrls": [
        "https://cdn.example.com/input.jpg"
      ]
    }
  }
}'

Parameters

3 parameters, the same for the SDK and for the inner params over REST. Required ones must be supplied; the rest fall back to their defaults.

Parameter	Type	Required	Default	Details
`prompt` What to make, in plain language: the subject, style and composition. With an input image or video, what to change.	`text`	yes	`—`	max 1000 chars
`aspectRatio` Shape of the output as width:height. An auto or adaptive option follows the input image.	`enum`	no	`16:9`	16:9, 9:16
`imageUrls` Input images, as URLs: the image to edit, or references for subject, style or composition.	`file (image[])`	yes	`—`	—

Response

generate() resolves once the job completes. One or more image URLs. Over REST the output is at response.result, inside the gateway's status envelope with the task id, its status and the amount charged.

json

{
  "items": [
    {
      "url": "https://cdn.picsart.com/…/result"
    }
  ],
  "model": "runway-gen4-ref"
}

json

{
  "status": "success",
  "response": {
    "id": "task_abc123",
    "status": "COMPLETED",
    "result": {
      "url": "https://cdn.picsart.com/…/result",
      "items": [
        {
          "url": "https://cdn.picsart.com/…/result"
        }
      ],
      "model": "runway-gen4-ref"
    }
  }
}

Overview

Alongside the unified model APIs, we expose compatibility APIs that take each vendor's original parameters exactly as the vendor defines them — nothing renamed, nothing reshaped on the way through.

That makes them the shortest path onto Picsart if you already work with the vendor directly: the request bodies you've already written keep working as they are. You keep their parameter names and defaults, and you get the vendor's full parameter set rather than the subset that is shared across every model.

The cost is that a request is written for one vendor — switching models later means rewriting it, and results come back in the vendor's own shape. When you'd rather write once and change models freely, use the unified API.

Make a request

Call the workflow with ai.apis.run() in TypeScript or Python, or hit /workflows/{workflow}/execute directly — params is passed through untouched either way.

These endpoints are addressed by workflow name rather than model id: the one in this model's header, since one model runs as one workflow. Authentication is unchanged — your Picsart API key as a bearer token (see Authentication).

import { createClient, ApiRunMode } from '@picsart/ai-sdk';

const ai = createClient({
  apiKey: process.env.PICSART_API_KEY,
  apiUrl: 'https://api.picsart.com',
});

// Calls the 'runway-gen4-image-ref' workflow directly — params are sent as-is.
const { result, usage } = await ai.apis.run('runway-gen4-image-ref', {
  promptText: "your value here",
  ratio: "1920:1080"
}, {
  mode: ApiRunMode.SYNC,
});

console.log(result); // workflow-specific output
console.log(usage?.credits); // amount charged, in $

python

import asyncio
import os

from picsart_ai_sdk import ApiRunMode, create_client


async def main() -> None:
    async with create_client(
        api_key=os.environ["PICSART_API_KEY"],
        api_url="https://api.picsart.com",
    ) as ai:
        # Calls the 'runway-gen4-image-ref' workflow directly — params are sent as-is.
        response = await ai.apis.run("runway-gen4-image-ref", {
            "promptText": "your value here",
            "ratio": "1920:1080",
        }, mode=ApiRunMode.SYNC)

        print(response["result"])  # workflow-specific output
        print((response.get("usage") or {}).get("credits"))  # amount charged, in $


asyncio.run(main())

bash

curl -X POST 'https://api.picsart.com/workflows/runway-gen4-image-ref/execute' \
  -H 'Authorization: Bearer $PICSART_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
  "params": {
    "promptText": "your value here",
    "ratio": "1920:1080"
  }
}'

Parameters

4 parameters, sent inside params. These are the vendor's own names, so they line up one-for-one with the vendor's documentation. Required ones must be supplied; the rest fall back to their defaults.

Parameter	Type	Required	Default	Details
`promptText` Prompt text for image generation	`string`	yes	`—`	max 1000 chars
`ratio` Aspect ratio for the generated image	`string`	yes	`—`	`1920:10801080:19201024:10241360:7681080:10801168:8801440:10801080:14401808:7682112:912`
`referenceImages` Reference images to be used in the generation process (max 3)	`ReferenceImage[]`	no	`—`	—
└`uri` URI of the reference image	`string`	yes	`—`	—
└`tag` A tag to identify the reference image. This is used to reference the image in prompt text.	`string`	no	`—`	3–16 chars · pattern ^[a-z][a-z0-9_]+$
`options` Options controlling safety checks and drive integration	`object`	no	`—`	—
└`safety_checks` Safety check settings	`object`	no	`—`	—
└`enabled` Whether to run content moderation. Defaults to true.	`boolean`	no	`—`	—
└`drive` Save result to Picsart Drive	`object`	no	`—`	—
└`name` File name in Picsart Drive	`string`	yes	`—`	—
└`attributes` Custom attributes to attach to the file	`object`	no	`—`	—
└`folder` Target folder in Picsart Drive	`object`	no	`—`	—
└`inputs_transformation` Input transformation settings	`object`	no	`—`	—
└`downscale_oversized_images` Whether to downscale oversized input images. Defaults to false.	`boolean`	no	`—`	—

Response

Over HTTP the output arrives inside a status envelope, at response.result. ai.apis.run() unwraps that envelope for you and resolves to { result, usage } instead. Either way the result itself is the vendor's own shape.

json

{
  "result": {
    "url": "https://cdn.picsart.com/…/result.jpg",
    "mimeType": "image/jpeg",
    "driveFile": {
      "id": "wf_abc123"
    }
  }
}

json

{
  "status": "success",
  "response": {
    "id": "wf_abc123",
    "status": "COMPLETED",
    "result": {
      "url": "https://cdn.picsart.com/…/result.jpg",
      "mimeType": "image/jpeg",
      "driveFile": {
        "id": "wf_abc123"
      }
    }
  }
}

RunwayRunway Gen4 Ref API

Params

Result

Other models from Runway

Install the SDK

Authenticate

Make a request

Parameters

Response

Overview

Make a request

Parameters

Response

Rates