I wanted to use Nano Banana in ComfyUI with my Google API instead of buying Comfy credits. I already had the $300 free trial sitting in Google Cloud.

I made an API key and tried a few of the custom nodes that let you use your own key. Every time I got this: `429 prepayment credits depleted`

Turns out Google changed it in March. That credit does not pay for Gemini API in AI Studio anymore, it says so in their own docs. And all the Gemini nodes use AI Studio, atleast the ones I checked.

Google has another door called Vertex AI. Same models, different address, and the credit does work there. You log in with gcloud instead of pasting a key.

So I made a node for it: [https://github.com/haristahir1/comfyui-gemini-ownkey](https://github.com/haristahir1/comfyui-gemini-ownkey)

What it does:

* Nano Banana Pro and 2.5 Flash Image
* text to image, or up to 14 reference images
* aspect ratio, and 1K 2K 4K
* a reference mode setting. By default Gemini copies the face from your reference photo even when your prompt describes someone completely different. You can turn that off, keep it on, or sit in the middle.
* switch between AI Studio and Vertex right in the node
* your key sits in a config file instead of the node, so it does not get saved into workflows you share with people
* two small scripts that tell you whether a problem is your login, your billing, or Google being down

Been generating with it on my own machine and it works. 2K comes out clean and the reference modes do what they say.

It is in ComfyUI Manager now, search "gemini own key". Or git clone it if you prefer. I only tested it on Windows portable, ComfyUI 0.34.2.

I vibe coded this so please check everything carefully & for fair use only! Double check your APIs and stuff. Cheers!

The $300 Google free trial does not work with any Gemini node in ComfyUI, so I made one that does