Images
February 17, 2026
Table of contents
Unified image generation endpoint supporting multiple Runway models: Nano Banana (nano-banana), Nano Banana Pro (nano-banana-pro), Gen-4 (gen4), and Gen-4 Turbo (gen4-turbo).
Nano Banana and Nano Banana Pro support image references of famous people and minors, unlike Google Flow.
Each model has different capabilities, reference image limits, resolution options, and optional parameters.
Accounts with a Runway Unlimited plan can set exploreMode to true to generate images without using credits. Explore mode generations are queued at lower priority and may take significantly longer — expect 5–15 minutes compared to 10–30 seconds for regular generations.
Model Comparison
| Feature | Nano Banana | Nano Banana Pro | Gen-4 | Gen-4 Turbo |
|---|---|---|---|---|
| Reference images | 0–3 | 0–14 | 0–3 | 1–3 (required) |
| Resolution | — | 1K, 2K, 4K | 1080p, 720p | 1080p |
| diversity | — | — | ✓ | — |
| seed | — | — | ✓ | ✓ |
| style | — | — | ✓ | ✓ |
Please be aware that Runway’s moderation system analyzes your image and 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.
The account you use to upload asset(s) via POST /assets will also be used to execute the generation. Uploading an asset to a specific account ensures that generation with that asset will occur under the same account.
https://api.useapi.net/v1/runwayml/images/create
Request Headers
Authorization: Bearer {API token}
Content-Type: application/json
# Alternatively you can use multipart/form-data
# Content-Type: multipart/form-data
API tokenis required, see Setup useapi.net for details.
Request Body
{
"model": "nano-banana-pro",
"email": "Optional Runway API account email",
"text_prompt": "Required text prompt",
"aspect_ratio": "16:9",
"resolution": "1K",
"num_images": 4,
"imageAssetId1": "user:user_id-runwayml:account_email-asset:asset_uuid",
"exploreMode": true,
"replyUrl": "Place your call back URL here",
"replyRef": "Place your reference id here",
"maxJobs": 5
}
-
modelis required. Supported values:nano-banana,nano-banana-pro,gen4,gen4-turbo. See model comparison for details. -
emailis optional, if not provided API will randomly select available account. -
text_promptis required. Describe your image in detail. Maximum length 5000 characters. -
aspect_ratiois optional. Supported values:16:9(default),9:16,1:1,4:3,3:4,21:9. resolutionis optional. Available resolutions depend on model.- Gen-4:
1080p(default),720p - Gen-4 Turbo:
1080p - Nano Banana Pro:
1K(default),2K,4K - Nano Banana: not supported
- Gen-4:
-
num_imagesis optional. Supported values:1(default),4. -
imageAssetId1throughimageAssetId14are optional. Specify the assetIds of reference images. Use GET /assets/?mediaType=image to see the list of image assets. To upload a new image asset use POST /assets. Parameters can be referred in the prompt as@IMG_1,@IMG_2, etc. Maximum number of reference images depends on model — see model comparison. -
diversityis optional. Aesthetic Range, higher values increase the creative variation between generations in a set. Only supported by Gen-4. When using reference images, defaults to 2. Valid range: 1…5. -
seedis optional. Only supported by Gen-4 and Gen-4 Turbo. Valid range 1…4294967294. -
styleis optional. Supported by Gen-4 and Gen-4 Turbo. Supported values:vivid,vivid-warm,vivid-cool,high-contrast,high-contrast-warm,high-contrast-cool,bw,bw-contrast,muted-pastel,dreamscape,nordic-minimal,light-anime,dark-anime,painted-anime,3d-cartoon,sketch,low-angle,in-motion,terracotta. -
exploreModeis optional. Set totrueif you have a Runway Unlimited plan and wish to execute relaxed generation. You are not charged credits for Explore mode generations. -
replyUrlis optional, if not provided value from useapi.net account will be used. Place here your callback URL. API will call the providedreplyUrlonce Runway task completed or failed. Maximum length 1024 characters. We recommend using sites like webhook.site to test callback URL functionality. -
replyRefis optional, place here your reference id which will be stored and returned along with this Runway task response / result. Maximum length 1024 characters. maxJobsis optional, if not provided value for referenced by image assetId 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 a429response. Once you get a429, 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
-
Use returned
taskIdto retrieve task status and results using GET /tasks/taskId. The generated images can be found in theartifactsarray of the task with the statusSUCCEEDED.If you specify the optional parameter
replyUrlthe API will call the providedreplyUrlwith task progress updates until the task is complete or fails.{ "task": { "id": "<uuid>", "name": "nano-banana-pro <your text prompt>", "image": null, "createdAt": "2026-02-17T23:58:27.296Z", "updatedAt": "2026-02-17T23:58:27.423Z", "taskType": "gemini_image", "options": { "name": "nano-banana-pro <your text prompt>", "text_prompt": "<your text prompt>", "reference_images": [ { "tag": "IMG_1", "assetId": "<asset uuid>", "url": "<asset CDN url>" } ], "aspect_ratio": "9:16", "image_size": "1K", "num_images": 1, "assetGroupId": "<uuid>", "creationSource": "tool-mode", "model": "gemini-3-pro-image-preview", "exploreMode": false, "recordingEnabled": true }, "status": "PENDING", "error": null, "progressText": null, "progressRatio": "0", "estimatedTimeToStartSeconds": 0, "artifacts": [], "sharedAsset": null, "sourceAssetId": null, "taskId": "user:user_id-runwayml:account_email-task:task_uuid", "code": 200 } } -
{ "error": "<Error message>", "code": 400 } -
{ "error": "Unauthorized", "code": 401 } -
You do not have enough credits to run this task.
{ "error": "You do not have enough credits to run this task." } -
Wait in a loop for at least 10..30 seconds and retry again.
When
exploreModeistrueand another explore mode job is still running, the new job will not start until the current one completes. Since explore mode generations can take 5–15 minutes, you may need to wait significantly longer before retrying.There are two possible cases for API response 429:
- API query is full and can not accept new images/create requests. Size of query defined by
maxJobsoptional 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>" } ] }, "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." } - API query is full and can not accept new images/create requests. Size of query defined by
Model
{ // TypeScript, all fields are optional
taskId: string,
id: string,
name: string,
image: string,
createdAt: string,
updatedAt: string,
taskType: string,
options: {
name: string,
text_prompt: string,
aspect_ratio: string,
num_images: number,
exploreMode: boolean,
seed: number,
diversity: number,
style: string,
width: number,
height: number,
flip: boolean,
model: string,
image_size: string,
reference_images: { assetId: string, url: string, tag: string }[],
creationSource: string,
assetGroupId: string,
recordingEnabled: boolean
},
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/images/create" \ -d '{"model": "nano-banana-pro", "text_prompt": "…"}' -
const model = "nano-banana-pro"; const text_prompt = "text prompt"; const apiUrl = `https://api.useapi.net/v1/runwayml/images/create`; const token = "API token"; const data = { method: 'POST', headers: { 'Authorization': `Bearer ${token}`, 'Content-Type': 'application/json' } }; data.body = JSON.stringify({ model, text_prompt }); const response = await fetch(apiUrl, data); const result = await response.json(); console.log("response", {response, result}); -
import requests model = "nano-banana-pro" text_prompt = "text prompt" apiUrl = f"https://api.useapi.net/v1/runwayml/images/create" token = "API token" headers = { "Content-Type": "application/json", "Authorization" : f"Bearer {token}" } body = { "model": f"{model}", "text_prompt": f"{text_prompt}" } response = requests.post(apiUrl, headers=headers, json=body) print(response, response.json())