codex

Install and update

npm i -g @openai/codex@latest

Setup bubblewrap

Codex specific workflow
/memories - turn on memories, specific information about project tech like preferences, tech stack

• memories are located in CODEX_HOME/memories

/fast - fast mode, consume 2 to 2.5x more usage
/statusline - display on the bottom bar

• useful one include, context used, 5h/weekly limit, token usage
• these will be saved in config.toml

Ctrl-T - open transcript

codex --yolo

• no sandbox, no ask for permission

Codex store it’s information in ~/.codex and support multiple profiles via CODEX_HOME variable

• default configuration file is in ~/.codex/config.toml

Instructions
Run this command to verify setup

codex --model gpt-5.4-mini --ask-for-approval never "Show which instruction files are active."

Useful workflows

• add steps to reproduce and constraints (if it’s a bug)
• break task into small steps
• have a clear definition of done

Agents: https://developers.openai.com/codex/subagents

• .codex/agents/agent.toml
• may require [mcp_servers.server_name]
• inherit same permission as workspace (e.g. YOLO)
• require name, description, developer_instructions

If a model and model_reasoning_effort is provided and the model is unavailable

• leave it blank for the current model

Skills https://developers.openai.com/codex/skills

• .agents/skills/<name>
• ~/.agents/skills

When using the $skill-installer, it installs system-wide

MCP: https://developers.openai.com/codex/mcp

• .codex/config.toml
• may need to be ignored by Git if it contain tokens
• custom configuration compared to .mcp.json

Use codex non-interactively

codex -a never exec --model gpt-5.4-mini "prompt"

Editor, Codex can use external editors such as vim for editing prompts and brings it back to the compose

VISUAL=vim codex

• or add it into .bashrc

Notification Hooks
https://developers.openai.com/codex/hooks
Located in CODEX_HOME/hooks.json or config.toml
Example

[[hooks.PostToolUse.hooks]]
type = "command"
command = '/usr/bin/python3 "$(git rev-parse --show-toplevel)/.codex/hooks/post_tool_use_review.py"'
timeout = 30
statusMessage = "Reviewing Bash output"

For permission request hook this is not possible. Look into tmux bell hooks project-setup

Codex now use remote-control for access on mobile

[Unit]
Description=Codex remote control bridge
After=network-online.target
 
[Service]
Type=simple
WorkingDirectory=/home/kevin
ExecStart=/home/kevin/.nvm/versions/node/v24.14.0/bin/codex remote-control
Restart=always
RestartSec=5
StandardOutput=append:/home/kevin/.codex/remote-control.log
StandardError=append:/home/kevin/.codex/remote-control.log
 
[Install]
WantedBy=default.target

• use this systemd service to keep it running
• use which codex to get the fullpath of Codex
• replace ~ with the user of the system