Codex
OpenAI's coding agent in Sikemux: install, sign-in, chats, accounts, limits and skills.
Codex is OpenAI’s coding agent. Sikemux runs the codex CLI, signed in with ChatGPT or an API key.
At a glance
| Command | codex |
| Chat in Sikemux | Yes, and its own TUI |
| Permission modes | Normal and YOLO |
| Effort levels | minimal, low, medium, high, xhigh, max |
| Several accounts | Yes |
| Plan limits in the rail | Yes |
Install
Click Install beside Codex on the welcome screen, or run:
curl -fsSL https://chatgpt.com/codex/install.sh | shIt installs to ~/.local/bin/codex. On a Mac, Sikemux also finds the copy of Codex inside the ChatGPT app.
Sign in
codex loginThis opens your browser to sign in with ChatGPT. Sikemux checks the sign-in with Codex itself and never stores your credentials.
How Sikemux runs it
A Codex chat talks to codex app-server, Codex’s own JSON-RPC server. Every step Codex takes (messages, commands, file changes, plans) shows up in the chat as it happens. Switch to TUI for Codex’s terminal interface.
Accounts and limits
Each Codex account is its own CODEX_HOME folder. Add one in Settings → Agents → Codex → Another account. The rail’s Limits shows each rate-limit window Codex reports for the selected account, with its reset time.
Skills
/skills in a Codex chat lists the skills Codex can use there, including the Sikemux library.