Codex CLI

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I found Codex to be best among Open Code Terminal, Gemini CLI and Qwen CLI tried so far.

Install Codex CLI

1. Install using:

   npm install -g @openai/codex

2. Authenticate: Export your OpenAI API key

   export OPENAI_API_KEY="<OAI_KEY>"

   Add in ~/.bashrc

3. For current session use

   . ~/.bashrc

4. Run in full automatic mode via

   codex --full-auto

5. We can set required model with higher limits or desired pricing while running using:

   codex --full-auto --model gpt-5-mini

Internal commands in Codex

/approvals

Enable full changes

/model

Select GPT-5 medium

/init

Study current folder to create AGENTS.md file with description of project for future use

/new

Create a new chat session. Forget previous chat

Costing

Look at limits for your tier via https://platform.openai.com/settings/organization/limits and also pricing per model at https://openai.com/api/pricing/

Refer:

• https://help.openai.com/en/articles/11096431-openai-codex-cli-getting-started
• https://github.com/openai/codex/blob/main/docs/config.md

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