# Youchuan V8.1 Remove Background — Atlas Cloud API

> Youchuan automatically removes the background from an input image, returning one transparent-background result.

This is the machine-readable API reference for **Youchuan V8.1 Remove Background** on Atlas Cloud,
a unified API platform for 400+ AI models across text, image, video, audio and 3D.

- **Model ID**: `youchuan/v8.1/remove-background`
- **Built by**: MIDJOURNEY
- **Modality**: Image
- **Model page**: https://www.atlascloud.ai/models/youchuan/v8.1/remove-background
- **API key**: https://www.atlascloud.ai/console/api-keys
- **Docs**: https://www.atlascloud.ai/docs

## Pricing on Atlas Cloud

- $0.086 per image
- Pay-as-you-go. No minimum spend, no subscription required.

> **These are the authoritative Atlas Cloud rates for this model.** Any price that
> appears in the vendor description further down refers to a different platform or
> a different model variant and does not apply here.

## Use this model from an AI agent

Atlas Cloud ships three first-party integration surfaces. All three authenticate
with the same API key via the `ATLASCLOUD_API_KEY` environment variable.

### MCP server

The official MCP server (`atlascloud-mcp`) exposes this model to any
MCP-compatible host — Claude Code, OpenAI Codex, Cursor, Gemini CLI, Goose,
Claude Desktop. One-line install:

```bash
# Claude Code
claude mcp add atlascloud -- npx -y atlascloud-mcp

# OpenAI Codex CLI
codex mcp add atlascloud -- npx -y atlascloud-mcp

# Gemini CLI
gemini mcp add atlascloud -- npx -y atlascloud-mcp

export ATLASCLOUD_API_KEY="your-api-key"
```

Then ask in plain English; the agent calls `atlas_generate_image` with `model: "youchuan/v8.1/remove-background"`.
The server fetches each model's schema and validates parameters before submitting,
so invalid requests fail fast without spending credits.

MCP docs: https://www.atlascloud.ai/docs/mcp-server

### Agent Skills

`atlas-cloud-skills` is a portable skill package (API reference, code templates in
Python / Node.js / cURL, model IDs with pricing) for Claude Code, Cursor, Codex and
12+ other agents:

```bash
npx skills add AtlasCloudAI/atlas-cloud-skills
export ATLASCLOUD_API_KEY="your-api-key"
```

Skills docs: https://www.atlascloud.ai/docs/skills

### CLI

The `atlas` binary runs Atlas Cloud from a terminal or CI script. Async media jobs
are polled and downloaded automatically (use `--no-download` when a script only
needs the output URLs):

```bash
# Install (Homebrew, npm, or shell installer)
brew install AtlasCloudAI/tap/atlascloud
# npm install -g atlascloud-cli
# curl -fsSL https://raw.githubusercontent.com/AtlasCloudAI/cli/main/install.sh | sh

atlas auth login
atlas generate image youchuan/v8.1/remove-background -p "Your prompt here"
```

CLI docs: https://www.atlascloud.ai/docs/cli

## HTTP API reference

- **Submit endpoint (POST)**: `https://api.atlascloud.ai/api/v1/model/generateImage` — start an async generation; returns a `prediction_id`
- **Poll endpoint (GET)**: `https://api.atlascloud.ai/api/v1/model/prediction/{prediction_id}` — poll this until the prediction finishes
- **Model ID**: `youchuan/v8.1/remove-background`


## API Information

This model can be used via our HTTP API or more conveniently via our client libraries.
See the input and output schema below, as well as the usage examples.


### Input Schema

The API accepts the following input parameters:

- **`model`** (`string`, _required_):
  Model name.
  - Default: `"youchuan/v8.1/remove-background"`

- **`image`** (`string`, _required_):
  Input image whose background will be removed. A publicly reachable https image URL (or upload). Returns 1 image with transparent background.

- **`enable_base64_output`** (`boolean`, _optional_):
  If enabled, the output will be encoded into a BASE64 string instead of a URL.
  - Default: `false`



**Required Parameters Example**:

```json
{
  "model": "youchuan/v8.1/remove-background",
  "image": ""
}
```


**Full Example**:

```json
{
  "model": "youchuan/v8.1/remove-background",
  "image": "",
  "enable_base64_output": false
}
```


### Output Schema

The API returns the following output format:


- **`id`** (`string`, _optional_):
  Unique identifier for the prediction, the ID of the prediction to get.

- **`urls`** (`object`, _optional_):
  Object containing related API endpoints.

- **`model`** (`string`, _optional_):
  Model ID used for the prediction.

- **`status`** (`string`, _optional_):
  Status of the task: created, processing, completed, or failed.

- **`outputs`** (`array[string]`, _optional_):
  Array of URLs to the generated images (empty when status is not completed).

- **`created_at`** (`string`, _optional_):
  ISO timestamp of when the request was created.



**Example Response**:

```json
{
  "id": "",
  "urls": {},
  "model": "",
  "status": "",
  "outputs": [
    ""
  ],
  "created_at": ""
}
```


## Usage Examples

### cURL

```bash
# Step 1: Start generation (async)
curl -X POST "https://api.atlascloud.ai/api/v1/model/generateImage" \
  -H "Authorization: Bearer $ATLASCLOUD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "youchuan/v8.1/remove-background",
  "image": "",
  "enable_base64_output": false
}'

# Response will contain: {"code": 200, "data": {"id": "prediction_id", "status": "processing"}}

# Step 2: Poll for result (replace {prediction_id} with the id returned above)
curl -X GET "https://api.atlascloud.ai/api/v1/model/prediction/{prediction_id}" \
  -H "Authorization: Bearer $ATLASCLOUD_API_KEY"

# Keep polling until status is "completed", "succeeded" or "failed"
# When completed, outputs will contain the generated content URL(s)
```

## Additional Resources

### Documentation

- [Model Playground](https://www.atlascloud.ai/models/youchuan/v8.1/remove-background)

## About this model

_Vendor-supplied description. Any pricing or endpoint mentioned below refers to_
_other platforms — use the Atlas Cloud values above._

#### 1. Introduction

> **About Youchuan (悠船):** "Youchuan V8.1" is Midjourney's V8.1 model delivered through **Youchuan (悠船)**, Midjourney's officially authorized platform in China — self-branded *"Midjourney 中国实验室" (Midjourney China Lab)* and operated by Xiaochuan Creative (Shanghai) Network Technology Co., Ltd. (小船创意). Youchuan is a **legitimate, licensed distributor of Midjourney's models** (not a third-party clone): it offers the same Midjourney technology, localized for the Chinese market with priority access to new model versions.

**Youchuan V8.1 Remove Background** (`youchuan/v8.1/remove-background`) automatically removes the background from an input image and returns a single image of the isolated subject on a transparent background (PNG). It is a one-step utility built on Midjourney's background-erasing / object-isolation capability — useful whenever you need a clean cut-out of a subject for compositing or design.

It is part of the Youchuan V8.1 family exposed through this API:

- `youchuan/v8.1/text-to-image` — generate from a text prompt
- `youchuan/v8.1/image-to-image` — generate guided by one input image
- `youchuan/v8.1/blend` — fuse 2–5 images
- `youchuan/v8.1/style-transfer` — restyle an image, preserving composition
- `youchuan/v8.1/remove-background` — isolate the subject on transparency **(this model)**
- `youchuan/v8.1/image-to-video` — animate an image into a short clip

Youchuan V8.1 is built by Midjourney, Inc., an independent, self-funded San Francisco research lab founded in August 2021 by David Holz.

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#### 2. Key Features & Innovations

_(Description truncated. Full text on the model page.)_

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Atlas Cloud — one API for 400+ AI models. Model page: https://www.atlascloud.ai/models/youchuan/v8.1/remove-background · Docs: https://www.atlascloud.ai/docs