Omnicodex

A minimal, lightning-fast CLI launcher and MCP middleware for Claude Code with interactive model selection and dynamic mid-session model switching via an Antigravity proxy.

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    Claude Code launcher  ·  powered by Antigravity

│
◇  Proxy is running
│
◇  10 models available
│
◆  Choose a starting model
│  ○ Claude Opus 4.6 (Thinking)        (Anthropic)
│  ○ Claude Sonnet 4.6 (Thinking)      (Anthropic)
│  ● Gemini 3.6 Flash (High)           (Google)
│  ○ Gemini 3.6 Flash (Medium)         (Google)
│  ○ Gemini 3.6 Flash (Low)            (Google)
│  ○ Gemini 3.1 Pro (High)             (Google)
│  ○ GPT-4o                            (OpenAI)
└

Key Features

• 🎯 Interactive Model Selection: Select from available Google, Anthropic, and OpenAI models with color-coded provider previews.
• ⚡ Auto Proxy Initialization: Automatically checks and starts the Antigravity proxy (acc start) if not running.
• 🤖 Built-in MCP Server: Auto-registers omnicodex Model Context Protocol (MCP) server into Claude Code settings with pre-approved permissions.
• 🔄 Dynamic Mid-Session Switching: Switch models mid-conversation without losing context or restarting Claude Code via CLI, natural language chat, or the /model command.
• 🛠️ Middleware Routing Proxy: Local proxy server dynamically swaps model endpoints on-the-fly and ensures seamless API compatibility.

Quick Start

Install globally via npm:

npm install -g omnicodex

Launch instantly using omnicodex or the short alias omni:

omnicodex
# or short alias:
omni

(Or run instantly without global installation: npx omnicodex)

Requirements

| Requirement | Version | Purpose | |---|---|---| | 🟢 Node.js | ≥ 18 | JavaScript runtime | | 🤖 Claude Code | latest | CLI tool launched by omnicodex | | ⚡ Antigravity Claude Proxy (acc) | latest | Local proxy providing LLM endpoints |

Usage & Commands

Interactive Launch & Quick Flags

omnicodex                 # Launch with interactive model picker
omni                      # Short alias
omnicodex -m <model-id>   # Direct launch (e.g. omnicodex -m gemini-pro-agent)
omnicodex -q              # Launch without displaying the ASCII banner

Management Commands

omnicodex switch          # Interactive mid-session model switcher picker
omnicodex set <model-id>  # Switch active session model directly (e.g. omnicodex set opus)
omnicodex current         # Display active session model
omnicodex list            # List all available models & providers
omnicodex status          # Show upstream proxy & middleware status
omnicodex --help          # Show help and command summary
omnicodex --version       # Display version

Mid-Session Model Switching (Zero Context Loss)

Need to switch from Sonnet to Gemini 3.1 Pro or Claude Opus mid-session? You can change models instantly without losing conversation state:

Option 1: Direct Natural Language in Claude Chat (MCP)

Thanks to the auto-configured MCP server, you can tell Claude Code directly:

• "Switch model to Gemini 3.1 Pro"
• "Use Opus model for this task"
• "Switch model to Flash High"
• "What model am I currently using?"

Option 2: Native /model Command

Inside Claude Code chat, type /model:

• Opus $\rightarrow$ maps to Gemini 3.1 Pro (gemini-pro-agent)
• Sonnet $\rightarrow$ maps to Claude Sonnet 4.6 (claude-sonnet-4-6)
• Haiku $\rightarrow$ maps to Gemini 3.6 Flash (gemini-3.6-flash-high)

Option 3: Second Terminal

Run from any terminal window:

omnicodex switch
# or set directly:
omnicodex set gemini-pro-agent

⚙️ How It Works Behind The Scenes

1. Proxy Check: Verifies if the Antigravity proxy is active on port 8080 (starts acc start automatically if offline).
2. Model Discovery: Queries http://localhost:8080/v1/models for available provider models.
3. Interactive Selection: Presents a terminal picker powered by @clack/prompts.
4. MCP & Settings Injection: Updates ~/.claude/settings.json with middleware port, token variables, MCP server declaration, and pre-approved tool permissions.
5. Middleware Server: Spawns a lightweight local HTTP middleware that dynamically rewrites model requests to the active LLM.
6. Launcher: Executes Claude Code CLI seamlessly attached to your active terminal.

Interactive Navigation

| Key | Action | |---|---| | ↑ / ↓ | Navigate model options | | Enter | Select model and launch | | Esc / Ctrl+C | Exit picker |

Development & Building

git clone https://github.com/lokeshhh-10/omnicodex.git
cd omnicodex

npm install          # Install dependencies
npm run build        # Build TypeScript output (dist/)
npm run dev          # Rebuild automatically on change
npm run test         # Run Vitest test suite
npm run lint         # Check formatting and linting

Troubleshooting

• omnicodex: command not found
  Ensure global npm binaries are in your system PATH:

  export PATH="$HOME/.local/share/npm/bin:$PATH"

• Proxy not running / acc missing
  Verify Antigravity CLI is installed and executable via acc --version.
• Permission Prompt for MCP tools in Claude Code
  OmniCodex automatically adds tool permissions to ~/.claude/settings.json. If prompted, select "Always allow".

License

MIT