# FLUX.2 Flex Text-to-Image — Atlas Cloud API

> FLUX.2 Flex is a professional text-to-image generation model specialized for typography, fine detail preservation, and production workflows requiring precise customization. It provides adjustable inference steps (1–50) and guidance scale (1.5–10) for fine-grained control, delivering high-quality output up to 4MP.

This is the machine-readable API reference for **FLUX.2 Flex 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-2-flex/text-to-image`
- **Built by**: Black Forest Labs
- **Modality**: Image
- **Model page**: https://www.atlascloud.ai/models/black-forest-labs/flux-2-flex/text-to-image
- **API key**: https://www.atlascloud.ai/console/api-keys
- **Docs**: https://www.atlascloud.ai/docs

## Pricing on Atlas Cloud

- $0.05 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-2-flex/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-2-flex/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-2-flex/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-2-flex/text-to-image"`

- **`prompt`** (`string`, _required_):
  Text prompt for image generation.

- **`enable_prompt_expansion`** (`boolean`, _optional_):
  Whether to use prompt upsampling to enhance the prompt before generation.
  - Default: `true`

- **`size`** (`string`, _optional_):
  Image dimensions in width*height format (e.g., 1024*1024, 1280*720), If not specified, the model will determine the optimal dimension.
  - Default: `"1024*1024"`
  - Min: 256
  - Max: 2048

- **`guidance_scale`** (`number`, _optional_):
  Guidance scale for image generation. High guidance scales improve prompt adherence at the cost of reduced realism.
  - Default: `5`
  - Min: 1.5
  - Max: 10

- **`num_inference_steps`** (`integer`, _optional_):
  Number of steps for image generation. Higher steps lead to more detailed and realistic images.
  - Default: `50`
  - Min: 1
  - Max: 50

- **`output_format`** (`string`, _optional_):
  The format of the output image.
  - Default: `"jpeg"`
  - Options: "jpeg", "png"

- **`safety_tolerance`** (`integer`, _optional_):
  Tolerance level for input and output moderation. Between 0 and 5, 0 being most strict, 5 being least strict.
  - Default: `2`
  - Min: 0
  - Max: 5

- **`seed`** (`integer`, _optional_):
  Random seed for reproducibility. Use -1 for a random seed.
  - Default: `-1`

- **`enable_base64_output`** (`boolean`, _optional_):
  If enabled, the output will be encoded into a BASE64 string instead of a URL. This property is only available through the API.
  - Default: `false`

- **`enable_sync_mode`** (`boolean`, _optional_):
  If set to true, the function will wait for the result to be generated and uploaded before returning the response. It allows you to get the result directly in the response. This property is only available through the API.
  - Default: `false`



**Required Parameters Example**:

```json
{
  "model": "black-forest-labs/flux-2-flex/text-to-image",
  "prompt": ""
}
```


**Full Example**:

```json
{
  "model": "black-forest-labs/flux-2-flex/text-to-image",
  "prompt": "",
  "enable_prompt_expansion": true,
  "size": "1024*1024",
  "guidance_scale": 5,
  "num_inference_steps": 50,
  "output_format": "jpeg",
  "safety_tolerance": 2,
  "seed": -1,
  "enable_base64_output": false,
  "enable_sync_mode": false
}
```


### Output Schema

The API returns the following output format:


- **`code`** (`integer`, _optional_):
  HTTP status code of the response.

- **`message`** (`string`, _optional_):
  Human-readable message; non-empty on failure.

- **`data`** (`object`, _optional_):
  - Properties:
    - **`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 content. Null when status is not completed.

    - **`urls`** (`object`, _optional_):
      Object containing related API endpoints.
      - Properties:
        - **`get`** (`string`, _optional_):
          URL to poll for the prediction result.


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

    - **`created_at`** (`string`, _optional_):
      ISO timestamp of when the request was created (e.g., "2023-04-01T12:34:56.789Z").

    - **`error`** (`string`, _optional_):
      Error message if the task failed, empty string otherwise.

    - **`error_code`** (`integer`, _optional_):
      Error code if the task failed.

    - **`executionTime`** (`number`, _optional_):
      Total execution time in milliseconds.

    - **`timings`** (`object`, _optional_):
      Detailed timing breakdown.
      - Properties:
        - **`inference`** (`number`, _optional_):
          Inference time in milliseconds.





**Example Response**:

```json
{
  "code": 0,
  "message": "",
  "data": {
    "id": "",
    "model": "",
    "outputs": [
      ""
    ],
    "urls": {
      "get": ""
    },
    "status": "",
    "created_at": "",
    "error": "",
    "error_code": 0,
    "executionTime": 0,
    "timings": {
      "inference": 0
    }
  }
}
```


## 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-2-flex/text-to-image",
  "prompt": "",
  "enable_prompt_expansion": true,
  "size": "1024*1024",
  "guidance_scale": 5,
  "num_inference_steps": 50,
  "output_format": "jpeg",
  "safety_tolerance": 2,
  "seed": -1,
  "enable_base64_output": false,
  "enable_sync_mode": 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/black-forest-labs/flux-2-flex/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.2 Flex — Text to Image

**Developer:** Black Forest Labs  
**Model ID:** `black-forest-labs/flux-2-flex/text-to-image`  
**Release Date:** February 23, 2026

#### Overview

FLUX.2 Flex is a professional text-to-image generation model specialized for typography, fine detail preservation, and production workflows requiring precise customization. Built on latent flow matching with a rectified flow transformer architecture, it provides adjustable inference steps (1–50) and a guidance scale (1.5–10) for fine-grained control over the diffusion process.

Compared to FLUX.2 Pro, FLUX.2 Flex offers greater parameter control — making it the preferred choice for workflows that require balancing speed against output quality, or for tasks where text rendering and hex-accurate color are critical. The latest version is up to 3× faster than previous FLUX.2 Flex releases while maintaining the same high output quality.

#### Key Capabilities

- **Superior typography** — Reliable text rendering for complex typography, infographics, memes, UI mockups, and marketing materials with legible fine text.
- **Adjustable inference parameters** — Fine-grained control through configurable steps (1–50) and guidance scale (1.5–10) to balance quality, speed, and prompt adherence.
- **High-resolution output up to 4MP** — Flexible aspect ratios with a fundamentally improved VAE achieving 63.5% better learnability (gFID) and 84.1% better reconstruction quality (LPIPS) versus prior architectures.
- **HEX color accuracy** — Precise color matching using hex color codes for brand-accurate asset creation.
- **Prompt expansion** — Optional automatic prompt enrichment to improve output quality from short or simple prompts.

#### Use Cases

_(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-2-flex/text-to-image · Docs: https://www.atlascloud.ai/docs