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Flux 2 LoRA: Text-to-Image with Custom LoRA & Precise Control on playground and API | RunComfy

blackforestlabs/flux-2/lora

Generate highly customized images with the Black Forest Labs Flux 2 model by applying up to three LoRA adapters for precise style and character control on RunComfy.

1. Get started

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

curl --request POST \
  --url https://model-api.runcomfy.net/v1/models/blackforestlabs/flux-2/lora \
  --header "Content-Type: application/json" \
  --header "Authorization: Bearer <token>" \
  --data '{
    "prompt": "GRPZA, dwarf warrior red beard, white background, game asset, pixel art"
  }'

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/lora \
  --header "Content-Type: application/json" \
  --header "Authorization: Bearer <token>" \
  --data '{
    "prompt": "GRPZA, dwarf warrior red beard, white background, game asset, pixel art"
  }'

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"
  ],
  "properties": {
    "prompt": {
      "title": "Prompt",
      "description": "The prompt to generate an image from.",
      "type": "string",
      "default": "GRPZA, dwarf warrior red beard, white background, game asset, pixel art"
    },
    "guidance_scale": {
      "title": "Guidance Scale",
      "description": "Guidance Scale is a measure of how close you want the model to stick to your prompt when looking for a related image to show you.",
      "type": "float",
      "minimum": 0,
      "maximum": 20,
      "default": 2.5
    },
    "seed": {
      "title": "Seed",
      "description": "The seed to use for the generation. If not provided, a random seed will be used.",
      "type": "integer",
      "default": 0
    },
    "num_inference_steps": {
      "title": "Number of Inference Steps",
      "description": "The number of inference steps to perform.",
      "type": "integer",
      "minimum": 4,
      "maximum": 50,
      "default": 28
    },
    "image_size": {
      "title": "Image Size",
      "description": "",
      "type": "string",
      "enum": [
        "square_hd",
        "square",
        "portrait_4_3",
        "portrait_16_9",
        "landscape_4_3",
        "landscape_16_9"
      ],
      "default": "landscape_4_3"
    },
    "output_format": {
      "title": "Output Format",
      "description": "The format of the generated image.",
      "type": "string",
      "enum": [
        "jpeg",
        "png",
        "webp"
      ],
      "default": "png"
    },
    "loras": {
      "title": "LoRAs",
      "description": "List of LoRA weights to apply (maximum 3). Each LoRA can be a URL, HuggingFace repo ID, or local path.",
      "type": "array",
      "default": [
        {
          "path": "gokaygokay/Flux-2D-Game-Assets-LoRA",
          "scale": 1
        }
      ],
      "items": {
        "path": {
          "title": "LoRA Path",
          "description": "URL, HuggingFace repo ID (owner/repo), or local path to LoRA weights.",
          "type": "string",
          "format": "str",
          "default": ""
        },
        "scale": {
          "title": "LoRA Scale",
          "description": "Scale factor for LoRA application (0.0 to 4.0). ",
          "type": "float",
          "format": "float_slider_with_range",
          "minimum": 0,
          "maximum": 4,
          "default": 1
        }
      },
      "maxItems": 3,
      "minItems": 0
    }
  }
}

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" }
      }
    }
  }
}