🐉 Project Chimera: The Gemini ↔ Claude Code Proxy

   ____ _   _ ___ __  __ _____ ____      _    
  / ___| | | |_ _|  \/  | ____|  _ \    / \   
 | |   | |_| || || |\/| |  _| | |_) |  / _ \  
 | |___|  _  || || |  | | |___|  _ <  / ___ \ 
  \____|_| |_|___|_|  |_|_____|_| \_\/_/   \_\

Project Chimera is a high-performance, stateful API proxy that stitches two rival AI architectures together: it uses Google Gemini (via web session cookies) as the backend brain for Anthropic's official claude-code CLI.

By bridging Claude's powerful terminal automation with Gemini's reasoning capabilities, Chimera gives you a zero-cost, high-speed CLI coding assistant that can read, write, and execute code directly on your local machine.

---

🔥 Key Features

• Zero API Costs: Uses your standard Gemini Web account via session cookies, completely bypassing paid API limits.
• Playwright Cookie Watchdog: Includes a background headless browser that silently wakes up at randomized intervals (20-40 minutes) to ping Google, rotate your session tokens, and keep your authentication alive indefinitely without triggering bot detection.
• "Delta Slicing" Algorithm: Claude Code sends massive, concatenated history payloads that normally trigger Google's XSS/Spam filters. Chimera tracks Google's native stateful memory and uses a custom "Delta Slicer" to only send the newest text on each turn, keeping the prompt ultra-lean.
• Bulletproof Tool Parsing: Custom fallback parsers gracefully handle Gemini's escaped quotes, hallucinatory JSON formatting, and identical-string Edit bugs to ensure your Python scripts and terminal commands are executed flawlessly.
• Auto-Healing Context: If Google throws an internal Error 13 (Context Desync), Chimera instantly catches it, fires a Playwright cookie refresh, and reconstructs the timeline behind the scenes without breaking your terminal flow.

---

⚠️ CRITICAL: The "Evil Clone" Logout Problem

Google's security backend is highly sensitive to concurrent sessions. If you extract cookies from your main personal Chrome profile and run this proxy, Google will see two identical sessions doing different things at the exact same time (one from your real browser, one from the headless Playwright browser).

Google will assume your session was hijacked by a hacker and will immediately hit the kill switch, logging you out of your Google account across all devices.

THE SOLUTION: You must create a Burner Chrome Profile (or use an entirely separate burner Google account) specifically for this proxy.

1. Open Chrome, click your Profile icon in the top right, and click Add.
2. Set up a new profile.
3. Log into Gemini on this new profile. Keep this profile closed when you aren't actively getting cookies.

---

🛠️ Installation & Setup

1. Install Dependencies

You need Python 3.8+ installed, along with Anthropic's official Claude Code CLI. Clone this repository, then install the required Python packages and the Playwright headless browser:

pip install fastapi uvicorn requests pydantic python-dotenv playwright
playwright install chromium

2. Extract Your Gemini Cookies (The Right Way)

We use the Cookie-Editor extension to grab a clean JSON export of your session.

1. Install the Cookie-Editor extension in your Burner Chrome Profile (Chrome Web Store Link).
2. Go to gemini.google.com and ensure you are logged in.
3. Click the Cookie-Editor extension icon in your browser toolbar.
4. Click Export -> Export as JSON (This copies the data to your clipboard).
5. In your project directory, create a file named cookies_raw.json and paste the clipboard contents into it.

3. Generate the Auth State

Run the setup script. This script acts as a sanitizer—it reads cookies_raw.json, cleans up any invalid formatting (like bad sameSite tags), and generates a perfect auth_state.json file for Playwright to use.

python setup.py

You should see: [+] Saved to auth_state.json

🚀 Running Project Chimera

Step 1: Start the Proxy Server

Run the proxy script in your terminal. It will load your auth_state.json, start the background Cookie Watchdog, and host a local API on port 8000.

python gemini_server.py

You should see the Chimera ASCII logo, followed by [*] Cookie Watchdog started.

Step 2: Route Claude Code to Localhost

Open a new, separate terminal window. You need to tell the claude-code CLI to ignore Anthropic's official billing servers and route its traffic to your local Chimera proxy.

Set the environment variables and launch Claude:

On Windows (PowerShell):

$env:ANTHROPIC_BASE_URL="http://127.0.0.1:8000/v1"
$env:ANTHROPIC_API_KEY="chimera_bypass"
claude

On Windows (CMD):

set ANTHROPIC_BASE_URL=http://127.0.0.1:8000/v1
set ANTHROPIC_API_KEY=chimera_bypass
claude

On Mac/Linux (Bash/Zsh):

export ANTHROPIC_BASE_URL="http://127.0.0.1:8000/v1"
export ANTHROPIC_API_KEY="chimera_bypass"
claude

---

🧠 Architecture: How it Works

Anthropic's claude-code CLI expects a stateless API, meaning it bundles the entire conversation history and all tool outputs into every single request it sends.

Google Gemini's Web UI is strictly stateful. It tracks a specific Chat ID on their servers. If you repeatedly send Gemini the exact same history it already remembers, its internal sequence tracker desyncs, and it silently rejects your prompt as a spam/XSS attack.

Project Chimera solves this conflict by:

1. Delta Slicing: Tracking the exact array of blocks sent to Google, comparing it against Claude's incoming payload, and extracting only the new messages and tool results to send forward.
2. Watchdog Persistence: Playwright runs silently in the background, injecting your auth_state.json into a headless Chromium instance, visiting Gemini to force Google to issue fresh TS (Timestamp) cookies, and saving them back to the JSON file so your session never dies.
3. Regex Repair: Gemini occasionally hallucinates unescaped quotes inside JSON strings. Chimera intercepts the raw text stream and surgically repairs malformed <TOOL_CALL> blocks before passing them to Claude for local execution.