# BLACKFORESTLABS FLUX 3 Text-to-Image — Atlas Cloud API

> Generate detailed, well-composed images from a text prompt with FLUX 3, in native 2K and 4K with precise layout control and improved text rendering.

This is the machine-readable API reference for **BLACKFORESTLABS FLUX 3 Text-to-Image** on Atlas Cloud,
a unified API platform for 400+ AI models across text, image, video, audio and 3D.

- **Model ID**: `black-forest-labs/flux-3/text-to-image`
- **Built by**: Black Forest Labs
- **Modality**: Image
- **Model page**: https://www.atlascloud.ai/models/black-forest-labs/flux-3/text-to-image
- **API key**: https://www.atlascloud.ai/console/api-keys
- **Docs**: https://www.atlascloud.ai/docs

## Pricing on Atlas Cloud

- $0.02 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: "black-forest-labs/flux-3/text-to-image"`.
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 black-forest-labs/flux-3/text-to-image -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**: `black-forest-labs/flux-3/text-to-image`


## 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: `"black-forest-labs/flux-3/text-to-image"`
  - Options: "black-forest-labs/flux-3/text-to-image"

- **`prompt`** (`string`, _required_):
  The prompt to generate an image from. Describe the subject first, then the action, setting, composition and style. Put exact text in quotes.

- **`aspect_ratio`** (`string`, _optional_):
  Output aspect ratio. auto lets the model choose.
  - Default: `"auto"`
  - Options: "auto", "21:9", "2:1", "16:9", "3:2", "7:5", "4:3", "5:4", "1:1", "4:5", "3:4", "5:7", "2:3", "9:16", "1:2"

- **`resolution`** (`string`, _optional_):
  Output resolution tier. Higher tiers take longer; 4k can take several minutes. Price is set by this tier.
  - Default: `"1k"`
  - Options: "768sq", "1k", "2k", "4k"

- **`enable_prompt_expansion`** (`boolean`, _optional_):
  Rewrites a short prompt into a fuller description while preserving its intent.
  - Default: `false`

- **`output_format`** (`string`, _optional_):
  Format of the generated image.
  - Default: `"jpeg"`
  - Options: "jpeg", "png"

- **`safety_tolerance`** (`integer`, _optional_):
  Safety tolerance level. 0 is the strictest and 4 is the most permissive.
  - Default: `2`
  - Min: 0
  - Max: 4



**Required Parameters Example**:

```json
{
  "model": "black-forest-labs/flux-3/text-to-image",
  "prompt": ""
}
```


**Full Example**:

```json
{
  "model": "black-forest-labs/flux-3/text-to-image",
  "prompt": "",
  "aspect_ratio": "auto",
  "resolution": "1k",
  "enable_prompt_expansion": false,
  "output_format": "jpeg",
  "safety_tolerance": 2
}
```


### Output Schema

The API returns the following output format:


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

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

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

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

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

- **`error`** (`string`, _optional_):
  Error message returned when the task fails.

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



**Example Response**:

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


## 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": "black-forest-labs/flux-3/text-to-image",
  "prompt": "",
  "aspect_ratio": "auto",
  "resolution": "1k",
  "enable_prompt_expansion": false,
  "output_format": "jpeg",
  "safety_tolerance": 2
}'

# 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/black-forest-labs/flux-3/text-to-image)

## About this model

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

### FLUX 3 Text-to-Image

**FLUX 3 Image** is Black Forest Labs' newest image model. It generates detailed, well-composed images from a text prompt, with native output up to 4K, precise layout control, and clean text rendering.

#### Why Choose This?

- **Native 2K and 4K** — pick a tier from `512sq` up to `4k` (16 MP). Fine textures, faces, patterns and small text stay sharp when you zoom, crop or print.
- **Improved text rendering** — well suited to graphic design, ads, posters and infographics.
- **Composition control** — trained to understand layout, so placement described in the prompt is followed closely.
- **One flat price per image**, set by the resolution tier.

#### Parameters

| Parameter | Required | Description |
| --- | --- | --- |
| `model` | Yes | `black-forest-labs/flux-3/text-to-image` |
| `prompt` | Yes | What to generate. |
| `aspect_ratio` | No | `auto`, `21:9`, `2:1`, `16:9`, `3:2`, `7:5`, `4:3`, `5:4`, `1:1`, `4:5`, `3:4`, `5:7`, `2:3`, `9:16`, `1:2`. Default `auto`. |
| `resolution` | No | `512sq`, `768sq`, `1k`, `2k`, `4k`. Default `1k`. Sets the price. |
| `enable_prompt_expansion` | No | Rewrites a short prompt into a fuller description, preserving intent. Default `false`. |
| `output_format` | No | `jpeg` or `png`. Default `jpeg`. |
| `safety_tolerance` | No | `0` (strictest) to `4` (most permissive). Default `2`. |

#### How to Use

```bash
curl -X POST "https://api.atlascloud.ai/api/v1/model/generateImage" \
  -H "Authorization: Bearer $AIP_API_KEY" \
  -H "Content-Type: application/json" \
  --data-raw '{
    "model": "black-forest-labs/flux-3/text-to-image",
    "prompt": "Ultra-wide cinematic shot of a fog-drenched coastal highway at dawn, cliffs on one side, turquoise sea on the other, a single vintage car with headlights on, soft golden rim light",
    "aspect_ratio": "21:9",
    "resolution": "2k",
    "output_format": "jpeg"
  }'
```

_(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/black-forest-labs/flux-3/text-to-image · Docs: https://www.atlascloud.ai/docs