blackforestlabs/flux-2/flex/edit

Create precise, photorealistic visuals from images or text with Flux 2 Flex, offering full control over color, composition, and style for professional design, branding, and marketing workflows.

1. Get started

Use RunComfy's API to run blackforestlabs/flux-2/flex/edit. For accepted inputs and outputs, see the model's schema.

curl --request POST \
  --url https://model-api.runcomfy.net/v1/models/blackforestlabs/flux-2/flex/edit \
  --header "Content-Type: application/json" \
  --header "Authorization: Bearer <token>" \
  --data '{
    "prompt": "Change colors of flowers flowing from rich #6a0dad to soft #ff69b4. Add an artistic carving text with a big font on helmet that says 'FLEX'.",
    "image_urls": [
      "https://playgrounds-storage-public.runcomfy.net/tools/7228/media-files/input-1-1.png"
    ]
  }'

2. Authentication

Set the YOUR_API_TOKEN environment variable with your API key (manage keys in your Profile) and include it on every request as a Bearer token via the Authorization header: Authorization: Bearer $YOUR_API_TOKEN.

3. API reference

Submit a request

Submit an asynchronous generation job and immediately receive a request_id plus URLs to check status, fetch results, and cancel.

curl --request POST \
  --url https://model-api.runcomfy.net/v1/models/blackforestlabs/flux-2/flex/edit \
  --header "Content-Type: application/json" \
  --header "Authorization: Bearer <token>" \
  --data '{
    "prompt": "Change colors of flowers flowing from rich #6a0dad to soft #ff69b4. Add an artistic carving text with a big font on helmet that says 'FLEX'.",
    "image_urls": [
      "https://playgrounds-storage-public.runcomfy.net/tools/7228/media-files/input-1-1.png"
    ]
  }'

Monitor request status

Fetch the current state for a request_id ("in_queue", "in_progress", "completed", or "cancelled").

curl --request GET \
  --url https://model-api.runcomfy.net/v1/requests/{request_id}/status \
  --header "Authorization: Bearer <token>"

Retrieve request results

Retrieve the final outputs and metadata for the given request_id; if the job is not complete, the response returns the current state so you can continue polling.

curl --request GET \
  --url https://model-api.runcomfy.net/v1/requests/{request_id}/result \
  --header "Authorization: Bearer <token>"

Cancel a request

Cancel a queued job by request_id, in-progress jobs cannot be cancelled.

curl --request POST \
  --url https://model-api.runcomfy.net/v1/requests/{request_id}/cancel \
  --header "Authorization: Bearer <token>"

4. File inputs

Hosted file (URL)

Provide a publicly reachable HTTPS URL. Ensure the host allows server‑side fetches (no login/cookies required) and isn't rate‑limited or blocking bots. Recommended limits: images ≤ 50 MB (~4K), videos ≤ 100 MB (~2–5 min @ 720p). Prefer stable or pre‑signed URLs for private assets.

5. Schema

Input schema

{
  "type": "object",
  "title": "Input",
  "required": [
    "prompt",
    "image_urls"
  ],
  "properties": {
    "prompt": {
      "title": "Prompt",
      "description": "The prompt to generate an image from.",
      "type": "string",
      "default": "Change colors of flowers flowing from rich #6a0dad to soft #ff69b4. Add an artistic carving text with a big font on helmet that says 'FLEX'."
    },
    "image_size": {
      "title": "Image Size",
      "description": "The size of the generated image. If auto, the size will be determined by the model. For custom image sizes, width and height can be passed as an object.",
      "type": "string",
      "enum": [
        "auto",
        "square_hd",
        "square",
        "portrait_4_3",
        "portrait_16_9",
        "landscape_4_3",
        "landscape_16_9"
      ],
      "default": "auto"
    },
    "enable_prompt_expansion": {
      "title": "Magic Prompt",
      "description": "Whether to expand the prompt using the model's own knowledge.",
      "type": "boolean",
      "default": true
    },
    "seed": {
      "title": "Seed",
      "description": "The seed to use for the generation.",
      "type": "integer",
      "default": 0
    },
    "output_format": {
      "title": "Output Format",
      "description": "The format of the generated image.",
      "type": "string",
      "enum": [
        "jpeg",
        "png"
      ],
      "default": "jpeg"
    },
    "image_urls": {
      "title": "Image URLs",
      "description": "List of URLs of input images for editing.",
      "type": "array",
      "items": {
        "type": "string",
        "format": "image_uri"
      },
      "maxItems": 10,
      "minItems": 1,
      "default": [
        "https://playgrounds-storage-public.runcomfy.net/tools/7228/media-files/input-1-1.png"
      ]
    },
    "guidance_scale": {
      "title": "Guidance Scale",
      "description": "The guidance scale to use for the generation.",
      "type": "float",
      "default": 3.5,
      "minimum": 1.5,
      "maximum": 10
    },
    "num_inference_steps": {
      "title": "Number of Inference Steps",
      "description": "The number of inference steps to perform.",
      "type": "integer",
      "default": 28,
      "minimum": 2,
      "maximum": 50
    }
  }
}

Output schema

{
  "output": {
    "type": "object",
    "properties": {
      "image": {
        "type": "string",
        "format": "uri",
        "description": "single image URL"
      },
      "video": {
        "type": "string",
        "format": "uri",
        "description": "single video URL"
      },
      "images": {
        "type": "array",
        "description": "multiple image URLs",
        "items": { "type": "string", "format": "uri" }
      },
      "videos": {
        "type": "array",
        "description": "multiple video URLs",
        "items": { "type": "string", "format": "uri" }
      }
    }
  }
}