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flux-1-schnell

Text-to-Image • Black Forest Labs
@cf/black-forest-labs/flux-1-schnell

FLUX.1 [schnell] is a 12 billion parameter rectified flow transformer capable of generating images from text descriptions.

Model Info
Unit Pricing$0.000053 per 512 by 512 tile, $0.00011 per step

Usage

Workers - Returning a data URI - TypeScript

 
export interface Env {
  AI: Ai;
}


export default {
  async fetch(request, env): Promise<Response> {
    const response = await env.AI.run('@cf/black-forest-labs/flux-1-schnell', {
      prompt: 'a cyberpunk lizard',
      seed: Math.floor(Math.random() * 10)
    });
    // response.image is base64 encoded which can be used directly as an <img src=""> data URI
    const dataURI = `data:image/jpeg;charset=utf-8;base64,${response.image}`;
    return Response.json({ dataURI });
  },
} satisfies ExportedHandler<Env>;

Workers - Returning an image - TypeScript

 
export interface Env {
  AI: Ai;
}


export default {
  async fetch(request, env): Promise<Response> {
    const response = await env.AI.run('@cf/black-forest-labs/flux-1-schnell', {
      prompt: 'a cyberpunk lizard',
      seed: Math.floor(Math.random() * 10)
    });
    // Convert from base64 string
    const binaryString = atob(response.image);
    // Create byte representation
    const img = Uint8Array.from(binaryString, (m) => m.codePointAt(0));
    return new Response(img, {
      headers: {
        'Content-Type': 'image/jpeg',
      },
    });
  },
} satisfies ExportedHandler<Env>;

curl
Terminal window
curl https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/ai/run/@cf/black-forest-labs/flux-1-schnell  \
  -X POST  \
  -H "Authorization: Bearer $CLOUDFLARE_API_TOKEN"  \
  -d '{ "prompt": "cyberpunk cat", "seed": "Random positive integer" }'

Parameters

* indicates a required field

Input

  • prompt * string min 1 max 2048

    A text description of the image you want to generate.

  • steps integer default 4 max 8

    The number of diffusion steps; higher values can improve quality but take longer.

Output

  • image string

    The generated image in Base64 format.

API Schemas

The following schemas are based on JSON Schema

{
    "type": "object",
    "properties": {
        "prompt": {
            "type": "string",
            "minLength": 1,
            "maxLength": 2048,
            "description": "A text description of the image you want to generate."
        },
        "steps": {
            "type": "integer",
            "default": 4,
            "maximum": 8,
            "description": "The number of diffusion steps; higher values can improve quality but take longer."
        }
    },
    "required": [
        "prompt"
    ]
}