Runway API examples: Gen-4.5 and Gen-4 image-to-video (useapi.net)

Runnable Node.js examples for the Runway API by useapi.net: generate Runway's own Gen-4.5 / Gen-4 / Gen-4 Turbo text-to-video and image-to-video, Aleph video-to-video and Frames images, plus the models Runway hosts, Seedance 2.5 / 2.0, Veo 3.1, Kling O3 / 3.0, MiniMax H3, Wan 3.0, FLUX 3, Sora 2, Grok Imagine 1.5, HappyHorse, Nano Banana / Pro, GPT Image and Seedream 5, with Act-Two character animation, lip-sync, Kling motion control and Topaz 4K upscale. It all runs through a simple REST API that drives your own Runway account, with no developer account or per-call metering; accounts on Runway's Unlimited plan can use credit-free exploreMode on images and most video models.

Each example reads a list of prompts from prompts.json, submits them through the useapi.net Runway API, polls each task until it is final, and downloads every result — so you can queue a batch and come back to the winners.

Example	What it does	Tutorial
video/	Batch-generate Gen-4.5 / Gen-4 video — text-to-video and first/last-frame image-to-video — with any hosted model selectable per prompt	How to Generate Runway Gen Videos via API
frames/	Batch-generate high-fidelity Frames images, including up to three reference images (@IMG_1–@IMG_3)	How to Batch-Generate Images with Runway Frames via API

Quick start

You need Node.js v21 or newer (no dependencies to install), a useapi.net API token, and a connected Runway account (one $15/month subscription covers every useapi.net API):

git clone https://github.com/useapi/runway-api.git
cd runway-api/video
node ./runwayml.mjs <API_TOKEN> <EMAIL>

API_TOKEN is your useapi.net token and EMAIL is your connected Runway account email — every script looks the account up by email automatically. Edit prompts.json in each folder to queue your own prompts. Every supported parameter is documented on the POST /videos/create and POST /frames/create endpoint pages.

Common questions

• Is there a Runway API? Yes, and this repo uses the useapi.net Runway API, which spends the credits of the Runway website plan you already pay for, credits Runway's own developer API can't use. Those credits reach models its developer price list doesn't sell: FLUX 3, Kling 2.6, Kling 3.0 Motion Control, Wan 2.2 Animate and Topaz 4K upscale (as of October 2026). Every model runs on one unified endpoint.
• Is there a Runway image-to-video API? Yes. Upload the still with POST /assets and pass its assetId as imageAssetId1 (the start frame) to POST /videos/create. For a first-to-last-frame transition, add imageAssetId2 on kling-3.0-pro or veo-3.1; the Gen-4.x models take a start frame only. The video/ example does both.
• Which models can I use? Pick one per request with model: gen4.5 (default), gen4, gen4-turbo, plus seedance-2-5, seedance-2 / -fast / -mini, veo-3.1, the kling-o3-* tiers, kling-3.0-pro / -standard, kling-2.6-pro, minimax-h3 / minimax-h3-max, wan-3.0 / wan-3.0-prime, flux-3, sora-2 / sora-2-pro, grok-imagine-1.5 and happyhorse-1.0.
• Where do I get an API key? You call this API with a useapi.net API token and connect your Runway account once with its email and password through the Runway setup. Create the Runway account with the email option (Google, Apple and SSO sign-ups aren't supported). You can start on a free Runway account, which gets unlimited Image Upscaler and Frames Describe runs through this API.
• How much does it cost? Through useapi.net a Runway credit costs $0.008 on Max billed yearly ($76/month for 9,500 credits), against $0.01 on Runway's developer API (as of October 2026). Generations cost the same credits as in the web app. The cost calculator prices every model on every plan.
• Can I make images, animate characters and lip-sync too? Yes: Frames and the unified images endpoint (13 models), Act-Two, lip-sync in 28+ languages and 4K upscale.
• How many accounts can I connect? Each useapi.net subscription covers 3 Runway accounts, and each extra $10/month subscription adds 3 more.
• More answers: Runway API questions.

Tutorials

• How to Generate Runway Gen Videos via API — text-to-video and first/last-frame image-to-video via the unified videos/create endpoint, the model lineup, and exploreMode
• How to Batch-Generate Images with Runway Frames via API — high-fidelity Frames images, styles, and up to three reference images

About useapi.net

useapi.net is an experimental REST API for AI services. The Runway API drives your own Runway account, so you spend your plan's credits at consumer rates instead of metered developer-API pricing. See the model matrix and pricing on the API overview.

Visit our Discord Server or Telegram Channel for any support questions and concerns.

We regularly post guides and tutorials on the YouTube Channel.

License

The example code in this repository is released under the MIT License. It covers the example scripts only, not the useapi.net service or API.