Codex CLI Architect MCP

An MCP (Model Context Protocol) server implementation for OpenAI's Codex CLI, enabling AI-powered coding assistance through standardized tool interfaces.

Features

• Technical Consultation: Get expert advice on architecture, design patterns, and technology choices
• Code Review: Comprehensive code quality and security analysis
• Code Explanation: Clear explanations of code snippets and programming concepts
• Read-Only File Access: Can read files in the current workspace (directory and subdirectories)
• Write Protection: Uses Codex CLI's read-only sandbox mode to prevent file modifications
• Sandboxed Execution: Runs with platform-specific sandboxing (Apple Seatbelt on macOS, Landlock/seccomp on Linux)
• No Code Modification: Focuses on analysis and advice, not code generation

Prerequisites

• Node.js 18+
• Codex CLI installed and logged in

Usage with MCP Clients

Claude Code

Register the MCP server with Claude Code:

# Using NPM package
claude mcp add codex -- npx codex-cli-architect-mcp

# With custom model configuration
claude mcp add codex -e CODEX_MODEL=gpt-5 -- npx codex-cli-architect-mcp

# With OpenAI API key
claude mcp add codex -e OPENAI_API_KEY=your-api-key-here -- npx codex-cli-architect-mcp

Other MCP Clients

Configure the MCP server in your client's settings file:

{
    "mcpServers": {
        "codex": {
            "command": "npx",
            "args": ["codex-cli-architect-mcp"],
            "env": {
                "OPENAI_API_KEY": "your-api-key-here",
                "CODEX_MODEL": "gpt-5",
                "CODEX_TIMEOUT": "300000"
            }
        }
    }
}

Available Tools

The MCP server provides the following tools:

1. codex_consult - Technical consultation for architecture, design patterns, and implementation strategies
2. codex_review - Comprehensive code review for quality, security, and best practices
3. codex_explain - Get clear explanations of code snippets or programming concepts

These tools are exposed through the MCP protocol and can be used by any MCP-compatible client.

Configuration

Environment variables:

• OPENAI_API_KEY - OpenAI API key for authentication (optional, uses ChatGPT login if not provided)
• CODEX_MODEL - Model to use (default: gpt-5)
• CODEX_TIMEOUT - Execution timeout in milliseconds (default: 300000)

Development

# Install dependencies
npm install

# Build
npm run build

# Development mode
npm run dev

# Run tests
npm test

License

MIT