Whisk Proxy

Generate images with Google Imagen 4 and Nano Banana — completely free. No API key, no paid subscription.

Uses Google Labs Flow API with your regular Google account. Chrome extension for one-click auth, CLI script for generation.

What is this?

A lightweight CLI tool and AI Agent Skill that generates images using Google's latest models through the Flow API (labs.google).

Key features:

• Free — only needs a Google account
• No dependencies — just Node.js 18+ and Chrome
• One-click auth — Chrome extension handles tokens automatically
• Auto-refresh — session cookie lasts ~30 days, no hourly re-auth
• 3 models — Imagen 4, Nano Banana, Reference-to-Image
• AI Agent Skill — works with Claude Code, Codex, and other AI agents

Quick Start

1. Install the Chrome Extension

1. Open chrome://extensions in Chrome
2. Enable "Developer mode" (toggle in top right)
3. Click "Load unpacked"
4. Select the extension/ folder from this project

2. Connect your Google account

1. Open labs.google/fx/tools/flow in Chrome
2. Sign in with your Google account
3. Click the Flow Proxy extension icon in the toolbar
4. Click "Connect"

That's it! Token auto-refreshes for ~30 days.

3. Generate images

# Default model (Imagen 4), 4 images
node scripts/generate.mjs -p "a cat astronaut floating in space"

# Nano Banana (fast, creative)
node scripts/generate.mjs -p "abstract painting in neon colors" -m banana

# Reference-to-Image (style transfer)
node scripts/generate.mjs -p "watercolor portrait of a woman" -m r2i

# Landscape banner
node scripts/generate.mjs -p "futuristic city skyline at sunset" -r 16:9

# Single image, save to specific folder
node scripts/generate.mjs -p "abstract background" -c 1 -o ./my-images

Models

Model	Flag	Best for
Imagen 4	-m imagen4	Highest quality, photorealistic (default)
Nano Banana	-m banana	Fast, creative generation
Reference-to-Image	-m r2i	Style transfer

CLI Options

Flag	Short	Default	Description
--prompt	-p	required	Image description (English works best)
--model	-m	imagen4	Model: imagen4, banana, r2i
--count	-c	4	Number of images per request (1-4)
--ratio	-r	1:1	Aspect ratio (see below)
--output	-o	.	Output directory
--seed	-s	random	Seed for reproducibility

Aspect Ratios

Ratio	Resolution	Best for
1:1	1024x1024	Avatars, icons, social posts
16:9	1365x768	Banners, covers, YouTube thumbnails
9:16	768x1365	Stories, reels, vertical posters
4:3	Classic	Presentations, photos
3:4	Classic	Portraits

Check Token Status

node scripts/status.mjs

How It Works

Chrome Extension              CLI Script
     |                             |
     | 1. User clicks "Connect"    |
     |                             |
     +--> extracts access_token    |
     |    from labs.google session |
     |                             |
     +--> extracts session cookie  |
     |    (~30 day lifetime)       |
     |                             |
     +--> POST to localhost:3847 --+
     |                             |
     |    2. Token saved to        |
     |    ~/.flow-proxy/token.json |
     |                             |
     |    3. generate.mjs sends    |
     |    request to Google API    |
     |                             |
     |    4. When token expires,   |
     |    auto-refreshes via       |
     |    session cookie           |

API endpoint: https://aisandbox-pa.googleapis.com/v1:runImageFx

Auth: OAuth Bearer token from Google Labs session, auto-refreshed via session cookie

Use as AI Agent Skill

This project follows the Agent Skills standard. Copy the folder to your skills directory:

cp -r whisk-proxy ~/.claude/skills/whisk-proxy

The AI agent will automatically discover the skill and use it when you ask to generate images.

Security

• All tokens are stored locally on your machine only (~/.flow-proxy/token.json)
• The Chrome extension only communicates with localhost:3847
• No data is sent to any third-party servers
• The auth server only binds to 127.0.0.1 (not accessible from network)

Troubleshooting

"No valid token found"

Install the Chrome extension and click "Connect" on the Flow page.

"Token expired" + no auto-refresh

Session cookie may have expired (~30 days). Click "Connect" again.

"API Error 403"

Your Google account may not have access. Use a personal Google account (not workspace).

"API Error 429"

Rate limited. Wait a few minutes and try again.

Extension says "Proxy server not running"

Run generate.mjs first — the auth server starts automatically.

Requirements

• Node.js 18+ (uses native fetch)
• Google Chrome (for the extension)
• Google account with access to labs.google
• No npm dependencies, no build step

License

MIT