Runway Gen-4.5

Runway Gen-4.5. 720p AI video generation, 2-10 seconds, with first-frame image support.

POST/v1/media/queue

from $0.25/second

Overview

Runway Gen-4.5 — 720p video generation with first-frame image support. Async operation — submit a job, poll for completion.

Property	Value
Model ID	`runway/gen-4.5`
Provider	Runway
Resolutions	720p
Aspect Ratios	16:9, 9:16
Duration	2–10 seconds
Audio Generation	Not supported
Billing	Dynamic (actual cost per job)
Pricing	from $0.25/second

Usage

All media models use the async job queue. Submit a job, then poll for the result.

Step 1: Submit Job

Text-to-Video

const res = await fetch('https://api.yepapi.com/v1/media/queue', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    model: 'runway/gen-4.5',
    prompt: 'A cinematic drone shot over a rugged coastline at golden hour',
    options: {
      aspectRatio: '16:9',
      duration: '5',
    },
  }),
});
const { data } = await res.json();
// data.jobId — use this to poll for results

curl -X POST https://api.yepapi.com/v1/media/queue \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "runway/gen-4.5", "prompt": "A cinematic drone shot over a rugged coastline", "options": {"aspectRatio": "16:9", "duration": "5"}}'

Image-to-Video

Pass a reference image via imageData to generate a video from a still image.

const res = await fetch('https://api.yepapi.com/v1/media/queue', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    model: 'runway/gen-4.5',
    prompt: 'Animate this scene — clouds drifting, light changing',
    options: {
      aspectRatio: '16:9',
      duration: '5',
    },
    imageData: {
      mimeType: 'image/jpeg',
      base64: '...', // Base64-encoded image
    },
  }),
});

Step 2: Poll for Result

const status = await fetch(`https://api.yepapi.com/v1/media/status/${data.jobId}`, {
  headers: { 'x-api-key': 'YOUR_API_KEY' },
});
const { data: job } = await status.json();
// job.status — "pending" | "processing" | "completed" | "failed"
// job.result.video — { mimeType, base64 } when completed

curl https://api.yepapi.com/v1/media/status/JOB_ID \
  -H "x-api-key: YOUR_API_KEY"

Request Body

Parameter	Type	Required	Description	Default
`model`	`string`	Yes	`runway/gen-4.5` or aliases `runway`, `runway-gen`	—
`prompt`	`string`	Yes	Text description of the video to generate	—
`options.aspectRatio`	`string`	No	One of: 16:9, 9:16	`16:9`
`options.resolution`	`string`	No	`720p`	`720p`
`options.duration`	`string`	No	`2` to `10` (seconds)	`5`
`options.imageRole`	`string`	No	How to use the input image: `first_frame`	`first_frame`
`imageData.mimeType`	`string`	No	MIME type of input image (image/png, image/jpeg, image/webp)	—
`imageData.base64`	`string`	No	Base64-encoded input image for image-to-video generation	—

Pricing

Tier	Cost/sec
All resolutions	$0.25

Example: 5-second video ≈ 5 x $0.25 = $1.25. Billing is dynamic — each job is billed from the actual cost of the finished video, so shorter or lower-resolution jobs cost less.

Info

Video jobs can take several minutes to complete. Results retained for 1 hour.

Under the Hood

Runway Gen-4.5

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