Codex

Bridge Claude with OpenAI's Codex CLI. Access GPT-5.4 for code generation, analysis, and review with automatic fallback to GPT-5.4-mini on quota limits.

Installation

Run in your terminal:

# Project scope (current project only)
claude mcp add codex-cli -- npx -y ask-codex-mcp

# User scope (all projects)
claude mcp add --scope user codex-cli -- npx -y ask-codex-mcp

Or install globally:

npm install -g ask-codex-mcp

Prerequisites

1. Node.js v20.0.0 or higher
2. Codex CLI installed and authenticated

Tools

Tool	Purpose
ask-codex	Send prompts to Codex CLI. Defaults to GPT-5.4 with automatic mini fallback
ping	Fast connection test to verify MCP setup

Models

• Default: gpt-5.4 (highest capability)
• Fallback: gpt-5.4-mini (automatic on quota errors)

Key Features

• GPT-5.4 access via the official Codex CLI
• JSONL output parsing for structured responses
• Automatic quota fallback from GPT-5.4 to mini
• Standard MCP transport works with 40+ clients

npm

• Package: ask-codex-mcp
• Binary: ask-codex-mcp