How to Integrate Codex with MCP from Claude Code (The Story of Getting Stuck with Codex-MCP 404)
Published:Dec 24, 2025 23:31
•1 min read
•Zenn Claude
Analysis
This article details the process of connecting Codex CLI as an MCP server from Claude Code (Claude CLI). It addresses the issue of the `claude mcp add codex-mcp codex mcp-server` command failing and explains how to handle the E404 error encountered when running `npx codex-mcp`. The article provides the environment details, including WSL2/Ubuntu, Node.js version, Codex CLI version, and Claude Code version. It also includes a verification command to check the Codex version. The article seems to be a troubleshooting guide for developers working with Claude and Codex.
Key Takeaways
Reference
“claude mcp add codex-mcp codex mcp-server が上手くいかなかった理由”