---
title: "Use Veo 3 in Hermes Agent via RunAPI — Video API Guide"
url: "https://runapi.ai/hermes-veo-3.md"
canonical: "https://runapi.ai/hermes-veo-3"
locale: "en"
model: "veo-3"
---

# Use Veo 3 in Hermes Agent.

Veo 3 is Google DeepMind's video generation model that produces 1080p clips up to 8 seconds with native audio — synchronized dialogue, ambient sound, and music generated alongside the video. Hermes Agent calls it through the RunAPI custom provider endpoint, reusing the same API key configured for chat.

## API example

```bash
curl -X POST https://runapi.ai/api/v1/veo_3_1/text_to_video \
  -H "Authorization: Bearer $RUNAPI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "veo-3.1",
    "prompt": "A woman walks through a bustling Tokyo street at night, neon signs reflecting on wet pavement. She speaks into her phone: I just arrived. Ambient city noise, distant car horns, light rain.",
    "duration_seconds": 8,
    "aspect_ratio": "16:9"
  }'

```

### Response

```json
{
  "task_id": "tsk_abc123",
  "status": "pending",
  "model": "veo-3.1"
}

```

## How it works

1. **Configure RunAPI** — Set RUNAPI_API_KEY in the environment where Hermes Agent runs. If you already added RunAPI as a custom:runapi provider for chat, the same key and base_url handle video generation — no separate Google Cloud credentials needed.
2. **Call Veo 3 text_to_video** — Send a POST to the text_to_video endpoint with model set to veo-3.1. Include a prompt with scene descriptions and audio cues (dialogue, ambient sounds). Set duration_seconds to 4, 6, or 8 and aspect_ratio to 16:9 or 9:16. Hermes Agent routes through the custom:runapi provider.
3. **Poll for the result** — The endpoint returns a task_id immediately. Poll the task status endpoint until the status changes to completed, then retrieve the output video URL. The video includes synchronized audio generated from your prompt.

## Parameters

| Parameter | Type | Description |
|-----------|------|-------------|
| `model` | `string` | Required. veo-3.1 (standard quality) or veo-3.1-fast (lower cost, faster generation). |
| `prompt` | `string` | Required. Scene description including visual action, camera movement, and audio cues for dialogue or ambient sound. |
| `duration_seconds` | `integer` | Optional. Video length in seconds. Accepted values: 4, 6, 8. Defaults to 8. |
| `aspect_ratio` | `string` | Optional. Output aspect ratio. Accepted values: 16:9, 9:16, auto. |
| `input_mode` | `string` | Optional. Generation mode. text (default), first_and_last_frames (keyframe-guided), or reference (style reference). |
| `first_frame_image_url` | `string` | Optional. URL of the first frame image. Used when input_mode is first_and_last_frames. |
| `last_frame_image_url` | `string` | Optional. URL of the last frame image. Used when input_mode is first_and_last_frames. |
| `reference_image_urls` | `array` | Optional. URLs of style reference images. Used when input_mode is reference. |
| `callback_url` | `string` | Optional. Webhook URL that receives a POST when the task completes. |

## FAQ

### Can I use Veo 3 in Hermes Agent?

Yes. Hermes Agent calls the RunAPI Veo 3 text_to_video endpoint through the custom:runapi provider. Set model to veo-3.1 and send the request with the same RUNAPI_API_KEY you use for chat. No Google Cloud account or separate video API credentials required.

### Veo 2 vs Veo 3 -- is the upgrade worth it?

Veo 3 adds native audio generation that Veo 2 lacks entirely. If you need synchronized dialogue, sound effects, or ambient audio with your video, Veo 3 is the only option. For silent video where visual quality is all that matters, Veo 2 can be more cost-effective.

### What is the difference between veo-3.1 and veo-3.1-fast?

Both produce video with native audio at up to 1080p. veo-3.1 uses the full quality pipeline and costs more per generation. veo-3.1-fast trades some visual fidelity for lower cost and faster turnaround -- suitable for drafts and iteration.

### Can I control camera movement and audio in Veo 3?

Yes. Describe camera motion in the prompt (dolly in, tracking shot, aerial pan) and Veo 3 interprets it with physics-aware simulation. For audio, include dialogue in quotes and describe ambient sounds -- the model generates synchronized audio natively, no separate TTS or sound library needed.

### How does Hermes Agent handle Veo 3's native audio generation?

Hermes Agent passes your prompt (including dialogue or sound descriptions) to the RunAPI Veo 3 endpoint. The model generates synchronized audio and video together. No separate audio pipeline is needed -- the output includes both tracks.

### Can I use Veo 3 with other models in a Hermes Agent multi-step workflow?

Yes. Hermes Agent can generate a reference image with Imagen 4 or Flux 2, use it as input for Veo 3 image-to-video generation, then add background music with Suno -- all orchestrated in one agent run.


## Links

- [Hermes Agent setup guide →](https://runapi.ai/hermes-agent)
- [Veo 3 on RunAPI →](https://runapi.ai/models/veo-3)
- [Model catalog](https://runapi.ai/models)
- [API docs](https://runapi.ai/docs)