
How to Add MCP Servers to Codex
openai.com/index/introducing-codex/OpenAI's coding agent (CLI, IDE, Cloud) with MCP server support — all surfaces share ~/.codex/config.toml.
Setup Guide
1. Locate the config file
~/.codex/config.toml2. Add a server configuration
Run the following command:
codex mcp add sequential-thinking npx -- -y @modelcontextprotocol/server-sequential-thinking3. Restart Codex
Restart or reload Codex to pick up the new MCP server configuration.