ComfyUI BFL Bridge

Custom nodes for ComfyUI that connect to the Black Forest Labs FLUX API for image generation, editing, and inpainting.

Runs on CPU-only servers since all inference happens via the BFL API.

Nodes

BFL Bridge (Text-to-Image)

Generate images using FLUX models via the BFL API.

Supported models:

• Flux 2 Pro / Pro Preview
• Flux 2 Flex
• Flux 2 Klein 9B Preview
• Flux 1.1 Pro / Pro Ultra

Inputs: api_key, model, prompt, width, height, seed, guidance, steps Output: IMAGE

BFL Bridge Kontext (Image Edit)

Edit images using FLUX Kontext API with multi-reference support (up to 3 input images).

Supported models:

• Flux Kontext Max
• Flux Kontext Pro

Inputs: api_key, model, prompt, seed, guidance, steps, image_0, image_1 (optional), image_2 (optional) Output: IMAGE

BFL Bridge Fill (Inpaint/Outpaint)

Inpainting and outpainting using FLUX.1 Fill Pro API.

Inputs: api_key, prompt, seed, guidance, steps, image, mask Output: IMAGE

Installation

Clone into your ComfyUI custom_nodes directory:

cd /path/to/ComfyUI/custom_nodes/
git clone https://github.com/cerridan/ComfyUI_BFLBridge.git

Install dependencies:

pip install aiohttp>=3.9.0 Pillow>=10.0.0 numpy>=1.24.0

Restart ComfyUI.

API Key

Get your API key from api.bfl.ai.

You can provide it in two ways (the node checks in this order):

1. Node input — enter the key directly in the api_key field on the node
2. Environment variable — set BFL_API_KEY and leave the node field empty

If both are provided, the node input takes priority. For server deployments, the environment variable is recommended so the key stays out of workflow files.

Requirements

• ComfyUI >= 0.18.x (uses comfy_api.latest V3 node interface)
• Python >= 3.10
• No GPU required (API-based)

License

Apache 2.0