ComfyUI - fal.ai Nano Banana Pro Nodes 🍌

Custom ComfyUI nodes for Nano Banana Pro (a.k.a. Nano Banana 2 / Gemini 3 Pro Image) via the fal.ai API.

Two nodes included:

Node	Description
Nano Banana Pro (Text to Image) 🍌	Generate images from text prompts
Nano Banana Pro (Image Edit) 🍌	Edit existing images with natural language

Installation

1. Clone or copy this folder into your ComfyUI custom_nodes directory:

   cd ComfyUI/custom_nodes
   git clone <this-repo> comfyui-fal-nano-banana-pro
   

2. Install the dependency (only requests — PIL/torch/numpy are already in ComfyUI):

   pip install requests
   

3. Set your fal.ai API key as an environment variable before launching ComfyUI:

   export FAL_KEY="your-fal-api-key-here"
   

   Get a key at: https://fal.ai/dashboard/keys

4. Restart ComfyUI. The nodes will appear under fal.ai/Nano Banana Pro.

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Safety Tolerance / Censorship — How It Works

This is likely the reason you're here, so here's the full picture:

Text-to-Image (fal-ai/nano-banana-pro)

• No safety_tolerance parameter is exposed on this endpoint.
• Content filtering is applied server-side by a combination of Google's Gemini model safety systems and fal.ai's infrastructure.
• You cannot reduce or disable filtering for text-to-image via the API.
• If a prompt is filtered, you'll typically get an empty images array or an error.

Image Editing (fal-ai/nano-banana-pro/edit)

• Exposes safety_tolerance as an API-only parameter (not in fal.ai's playground UI).
• Scale of 1 to 6:
  • 1 = Most strict (blocks the most content)
  • 6 = Least strict (blocks the least content)
  • Default = 4
• This is included as a dropdown in the ComfyUI node.
• Important: Even at level 6, the underlying Gemini model still has Google's built-in safety filters. The safety_tolerance parameter adjusts fal.ai's additional filtering layer on top of the model — it does not remove the model's own refusals.

What this means in practice

• Setting safety_tolerance to 6 on the edit node will let more borderline content through fal.ai's filter, but Google's model-level safety can still refuse to generate certain content.
• The text-to-image node has no equivalent knob — you're subject to whatever the default filtering is.
• If you get empty results, check the description output — it sometimes contains the model's refusal reason.

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Node Parameters

Text to Image

Parameter	Type	Default	Notes
prompt	string	—	Required
num_images	int	1	1–4
aspect_ratio	enum	1:1	10 options
output_format	enum	png	png/jpeg/webp
resolution	enum	1K	1K/2K/4K (4K costs 2x)
seed	int	-1	-1 = random
limit_generations	bool	false	Force exactly 1 image per generation round
enable_web_search	bool	false	Let the model search the web (+$0.015)
timeout	int	300	Max seconds to wait

Image Edit

All of the above, plus:

Parameter	Type	Default	Notes
image	IMAGE	—	Required, primary input image
image_2	IMAGE	—	Optional second reference image
image_3	IMAGE	—	Optional third reference image
safety_tolerance	enum	4	1 (strict) → 6 (permissive). API-only.

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Pricing (fal.ai)

• $0.15 per image at 1K/2K
• $0.30 per image at 4K
• +$0.015 if web search is enabled

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License

MIT