How to Use the Veo 3.1 Image to Video API: image to video integration guide (2026)

Veo 3.1 Image to Video is an image to video model by Google: Cinematic I2V with Audio. Converts images to 1080p video with synchronized sound and start/end frame interpolation. On NamiFusion you can try it in the playground (exact quote shown before you submit), then call it through one unified REST API — a typical run costs about $3.20.

TL;DR

· Task type: image to video, provided by Google

· Pricing: about $3.20 per typical run ($1 = 100 credits), pay-as-you-go

· Getting started: playground (exact quote before submit) → create an API key → one POST request

· Tunable parameters: 9 (see the table below)

· No platform watermark; commercial use allowed (per the Terms of Service)

What can you build with Veo 3.1 Image to Video?

Short-form video and ad clips: go from a prompt or a single image to publishable motion content.

Product demos and concept previews: validate storyboards and visual direction cheaply before any shoot.

A social content factory: batch vertical clips and ride trending topics fast.

Remixing existing assets: image-to-video brings static work to life and extends its lifespan.

How do you call this API?

1. Sign up on NamiFusion and create a key on the API Keys page (free credits on signup).

2. Submit a task with the cURL example below, passing your key as a Bearer token.

3. Poll the task status with the returned task_uuid and read the output URLs when completed.

# 1) Submit — returns { "task_uuid": "..." }
curl -X POST "https://www.namifusion.com/api/v1/marketplace/run/google/veo3.1/image-to-video" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "input": {
    "image": "https://kaito-1328216764.cos.ap-tokyo.myqcloud.com/marketplace/thumbnails/2026-01-27/8b14994924bd.jpeg",
    "prompt": "Cinematic aerial drone shot of a modern metropolis at twilight, transitioning into night. The city lights flicker on one by one, creating a glowing grid against the deep blue hour sky. The camera glides smoothly between skyscrapers, revealing moving traffic streams below. High production value, 8k resolution, volumetric fog. Audio: Ambient city hum, wind rushing past the camera, and a swelling, majestic orchestral score that builds tension.",
    "aspect_ratio": "16:9",
    "duration": "8",
    "resolution": "1080p",
    "generate_audio": true,
    "negative_prompt": "shaky camera, blurry, low resolution, static, silence, distorted audio, pixelated, text, watermark, cartoon, overexposed",
    "seed": 42
  }
}'

# 2) Poll until status is "completed", then read the output URLs
curl "https://www.namifusion.com/api/v1/marketplace/run/tasks/TASK_UUID" \
  -H "Authorization: Bearer YOUR_API_KEY"

What parameters does it take?

image (Input Image): required

last_image (End Image): optional

prompt (Prompt): required

aspect_ratio (Aspect Ratio): optional, default "16:9"

duration (Duration): optional, default "8"

resolution (Resolution): optional, default "1080p"

generate_audio (Generate Audio): optional, default true

negative_prompt (Negative Prompt): optional

seed (Seed): optional

How do you write prompts for Veo 3.1 Image to Video?

1. Subject first: lead with the actor and action, then add environment, lighting and style ("an astronaut sprinting through a neon street in the rain, cinematic, shallow depth of field").

2. Concrete nouns beat stacked adjectives: "85mm portrait lens, golden-hour backlight" works far better than "very beautiful, ultra high quality".

3. Change one variable per iteration: pin the seed to reproduce a result, tweak a single phrase at a time so you know what actually moved the output.

4. State negatives positively: instead of "no blur", ask for "sharp focus, crisp details".

How much does it cost?

Pay-per-use in credits. A typical run costs about $3.20 ($1 = 100 credits); the exact price varies with parameters like resolution or duration, and the playground shows the exact quote before you submit.