Codex CLI

Codex CLI uses a global configuration file rather than per-project MCP config. CCE registers itself in the user-level config with a project-specific section.

Quick setup

cce init --agent codex

Or let CCE auto-detect (if ~/.codex/ exists or the VS Code OpenAI extension is installed):

cce init

Files created

~/.codex/config.toml

Codex CLI reads MCP servers from this single user-global file. CCE adds one section per project, keyed by a slug derived from the project’s absolute path:

[mcp_servers.cce-my-project-a3f2b1]
command = "cce"
args = ["serve", "--project-dir", "/path/to/your/project"]

Multiple projects coexist in the same file. Each gets a unique section name (cce-<basename>-<hash>) so two projects named “api” in different directories won’t collide.

AGENTS.md

Contains instructions for Codex to use context_search for code exploration. The CCE block is wrapped in markers so your own content is preserved during upgrades.

Important notes

• Codex CLI does not support per-project .mcp.json files. The global ~/.codex/config.toml is the only location for MCP server registration.
• Running cce uninstall removes only the section for the current project.
• If you’re using Codex via the VS Code extension (not the CLI), CCE detects it by looking for openai.* directories under ~/.vscode/extensions/.

Verify it’s working

1. After cce init, start a new Codex session in your project directory
2. Ask a code question:

How does error handling work in this project?

3. Check that Codex calls context_search in the tool output
4. Verify savings:

cce savings

Cross-agent memory

Decisions recorded during Claude Code sessions (record_decision) are stored in the project’s memory.db and shared across all agents. If you switch between Claude Code and Codex on the same project, session_recall returns decisions from both.

Troubleshooting

”cce: command not found” in Codex

Codex resolves commands from your shell’s PATH. If you installed with uv tool install:

• macOS/Linux: Ensure ~/.local/bin is in your PATH (add to ~/.zshrc or ~/.bashrc)
• Windows: Ensure %USERPROFILE%\.local\bin is in your system PATH

Codex doesn’t detect the MCP server

Check that ~/.codex/config.toml exists and contains the [mcp_servers.cce-...] section:

cat ~/.codex/config.toml | grep cce

If missing, re-run cce init --agent codex.

Multiple projects interfering

Each project section in config.toml includes --project-dir pointing to the correct path. If you renamed or moved a project, run cce uninstall in the old location and cce init --agent codex in the new one.

Windows: config.toml path

On Windows, the config file is at %USERPROFILE%\.codex\config.toml. CCE handles backslash escaping in TOML automatically, but if you edit the file manually, use forward slashes or double backslashes in paths.