> For the complete documentation index, see [llms.txt](https://bountyv.gitbook.io/vdocs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://bountyv.gitbook.io/vdocs/image-api/images-overview.md).

# Overview

Text-to-image generation, instruction-based editing, image-to-image/inpaint, and image-to-video animation across five self-hosted engines (Z-Image, SDXL, SD1.5, Qwen-Image, FLUX.2) plus SFW-only external engines (Seedream, Nano Banana Pro, ChatGPT Image).

## Endpoints

| Endpoint                                                   | Method                          | Description                                                                                                                         |
| ---------------------------------------------------------- | ------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
| [Text-to-Image](/vdocs/image-api/images-txt2img.md)        | `POST /api/v1/images/txt2img`   | Generate an image from a text prompt across five self-hosted architectures plus three SFW external engines                          |
| [Image Edit](/vdocs/image-api/images-edit.md)              | `POST /api/v1/images/edit`      | Instruction edits — undress, add-cum, anime→real, outfit swap, and more                                                             |
| [Image-to-Image / Inpaint](/vdocs/image-api/images-i2i.md) | `POST /api/v1/images/i2i`       | Re-render an image at a chosen denoise strength, optionally masked. Composes from up to 16 reference images on the external engines |
| [Image-to-Video](/vdocs/image-api/images-img2video.md)     | `POST /api/v1/images/img2video` | Animate a still with self-hosted Wan 2.2 (async submit + poll)                                                                      |

All endpoints require the header:

```
Authorization: Bearer sk_live_...
```

See [Authentication](/vdocs/authentication.md) for details.

## Access required

Endpoints here are gated by one of two entitlements:

* **`image`** — the SFW lane: Text-to-Image called with `"mode": "sfw"`.
* **`nsfw`** — the adult lanes: Text-to-Image called with `"mode": "nsfw"`, plus Image Edit, Image-to-Image / Inpaint, and Image-to-Video (all three are `nsfw`-only — there is no SFW mode for them).

If you can read this page but get a `403` `product_disabled`-style error when you call an endpoint, contact your account manager to enable that product on your account.

## Quick start

```bash
curl -X POST https://substance-api.com/api/v1/images/txt2img \
  -H "Authorization: Bearer sk_live_..." \
  -H "Content-Type: application/json" \
  -d '{"prompt": "a woman in a sunlit kitchen", "engine": "zimage", "mode": "sfw"}'
```

Each image endpoint returns its result on success (or a job ID to poll, for Image-to-Video) and charges your pooled credits on completion. Failed generations are refunded automatically — see [Errors](/vdocs/errors.md).

## Safety

Every prompt passes an age-safety blocklist and is augmented with adult-positive / minor-negative tokens, and outputs are additionally screened after generation. Prompts implying minors are rejected with `400` on every endpoint in this group.

## Pricing

Billed per call — see [Credits & pricing](/vdocs/account/credits.md) for current rates. Per-call pricing varies by endpoint and, on Text-to-Image and Image-to-Image, by the selected `engine`.


---

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