use-codex

Overview

codex is the OpenAI Codex CLI (an agentic coding tool like Claude Code, but GPT-backed). You can shell out to it with Bash to hand a whole task to Codex and let it work autonomously, then read back its result. Use this to offload work, get a different model's take, or run a flock of Codex agents in parallel.

Core principle: codex exec is the non-interactive entrypoint. Give it a self-contained prompt, run it unattended, capture the final message from a file. One codex exec call = one autonomous agent.

Before launching: ask model + effort

If the user did NOT specify, ask them which model and which reasoning effort before running. Do not silently pick.

• Effort values: minimal | low | medium | high. High = slowest/smartest.
• Model: e.g. gpt-5.6-sol. If unsure of available names, the config defaults live in ~/.codex/config.toml (grep -i model ~/.codex/config.toml); offer that default. Always pass --model explicitly — the model misreports its own name, so never rely on self-report and never assume the config default is what the user wants.

The autonomous invocation (copy this)